METHODS:

Inclusion was limited to those with abdominal CT-scans with and without contrast enhancement within 120 days. Analytic Morphomics, a semi-automated computational image processing system, was used to provide standardized, granular, anatomically indexed measurements of aortic wall calcification from abdominal CT-scans. Aortic calcification area (ACA) and aortic wall calcification percent (ACP) and were the outcomes of interest. Multiple linear regression was used to evaluate the relationship of aortic measurements. Models were further controlled for age and sex. Stratification of measurements by vertebral level was also performed.

RESULTS:

A positive association was observed for non-contrast calcification in ACP β 0.74 (95% CI 0.72, 0.76) and ACA β 0.44 (95% 0.43, 0.45). Stratified results demonstrated the highest coefficient of determination at L2 for percent and L3 for area models [R²> 0.91 (ACP) 0.74 (ACA)]. Adjusted lumber-level associations between non-contrast and contrast measurements ranged from (β 0.69-0.82) in ACP and (β 0.37-0.54) in ACA.

CONCLUSION:

A straightforward correction score for comparison of abdominal aortic calcification measurements in contrast-enhanced and non-contrast scans is discussed. Correction of aortic calcification from CT scans can reduce scan heterogeneity and will be instrumental in creating larger cardiovascular cohorts as well as cardiovascular risk surveillance programs.

Healthy US population reference values for CT visceral fat measurements and the impact of IV contrast, HU range, and spinal levels.

Derstine BA, Holcombe SA, Ross BE, Wang NC, Wang SC, Su GL

Sci Rep. 2022 Feb 11;12(1):2374.

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ABSTRACT:

Measurements of visceral adipose tissue cross-sectional area and radiation attenuation from computed tomography (CT) scans provide useful information about risk and mortality. However, scan protocols vary, encompassing differing vertebra levels and utilizing differing phases of contrast enhancement. Furthermore, fat measurements have been extracted from CT using different Hounsfield Unit (HU) ranges. To our knowledge, there have been no large studies of healthy cohorts that reported reference values for visceral fat area and radiation attenuation at multiple vertebra levels, for different contrast phases, and using different fat HU ranges. Two-phase CT scans from 1,677 healthy, adult kidney donors (age 18-65) between 1999 and 2017, previously studied to determine healthy reference values for skeletal muscle measures, were utilized. Visceral adipose tissue cross-sectional area (VFA) and radiation attenuation (VFRA) measures were quantified using axial slices at T10 through L4 vertebra levels. T-tests were used to compare males and females, while paired t-tests were conducted to determine the effect (magnitude and direction) of (a) contrast enhancement and (b) different fat HU ranges on each fat measure at each vertebra level. We report the means, standard deviations, and effect sizes of contrast enhancement and fat HU range. Male and female VFA and VFRA were significantly different at all vertebra levels in both contrast and non-contrast scans. Peak VFA was observed at L4 in females and L2 in males, while peak VFRA was observed at L1 in both females and males. In general, non-contrast scans showed significantly greater VFA and VFRA compared to contrast scans. The average paired difference due to contrast ranged from 1.6 to - 8% (VFA) and 3.2 to - 3.0% (VFRA) of the non-contrast value. HU range showed much greater differences in VFA and VFRA than contrast. The average paired differences due to HU range ranged from - 5.3 to 22.2% (VFA) and - 5.9 to 13.6% (VFRA) in non-contrast scans, and - 4.4 to 20.2% (VFA) and - 4.1 to 12.6% (VFRA) in contrast scans. The - 190 to - 30 HU range showed the largest differences in both VFA (10.8% to 22.2%) and VFRA (7.6% to 13.6%) compared to the reference range (- 205 to - 51 HU). Incidentally, we found that differences in lung inflation result in very large differences in visceral fat measures, particularly in the thoracic region. We assessed the independent effects of contrast presence and fat HU ranges on visceral fat cross-sectional area and mean radiation attenuation, finding significant differences particularly between different fat HU ranges. These results demonstrate that CT measurements of visceral fat area and radiation attenuation are strongly dependent upon contrast presence, fat HU range, sex, breath cycle, and vertebra level of measurement. We quantified contrast and non-contrast reference values separately for males and females, using different fat HU ranges, for lumbar and thoracic CT visceral fat measures at multiple vertebra levels in a healthy adult US population.

2021

The psoas muscle index distribution and influence of outcomes in an Asian adult trauma population: an alternative indicator for sarcopenia of acute diseases.

Tee YS, Cheng CT, Wu YT, Kang SC, Derstine BA, Fu CY, Liao CH, Su GL, Wang SC, Hsieh CH

Eur J Trauma Emerg Surg. 2021 Dec; 47(6):1787-1795.

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BACKGROUND:

Sarcopenia has been shown to be an independent negative predictor in various diseases. The measurement of pre-defined criteria of skeletal muscle in patients with acute disease is usually unavailable. Therefore, we evaluate the psoas muscle area based on computed tomography (CT) imaging as an alternative for sarcopenia in an Asian trauma population.

METHODS:

Derstine BA, Holcombe SA, Ross BE, Wang NC, Su GL, Wang SC

Sci Rep. 2021 Jan 11; 11(1):279

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ABSTRACT:

Measurements of skeletal muscle cross-sectional area (SMA) at the level of the third lumbar (L3) vertebra derived from clinical computed tomography (CT) scans are commonly used in assessments of sarcopenia, the loss of skeletal muscle mass and function associated with aging. As SMA is correlated with height and Body Mass Index (BMI), body size adjustment is necessary to fairly assess sarcopenic low muscle mass in individuals of different height and BMI. The skeletal muscle index, a widely used measure, adjusts for height as $(S M A / h e i g h t^{2})$ but uses no BMI adjustment. There is no agreed upon standard for body size adjustment. We extracted L3 SMA using non-contrast-enhanced CT scans from healthy adults, split into ‘Under-40’ and ‘Over-40’ cohorts. Sex-specific allometric analysis showed that height to the power of one was the optimal integer coefficient for height adjusted SMA in both males and females. We computed two height-adjusted measures $S M A_{HT} = S M A / h e i g h t$ and $S M A_{H T 2} = S M A / h e i g h t^{2}$ , comparing their Pearson correlations versus age, height, weight, and BMI separately by sex and cohort. Finally, in the ‘Under-40’ cohort, we used linear regression to convert each height-adjusted measure into a z-score ( $z (S M A_{HT})$ , $z (S M A_{H T 2})$ ) adjusted for BMI. $S M A_{HT}$ was less correlated with height in both males and females ( $r = 0.005$ , $p = 0.91$ and $r = 0.1$ , $p = 0.01$ ) than $S M A_{H T 2}$ ( $r = - 0.30$ and $r = - 0.21$ , $p < 0.001$ ). $z (S M A_{HT})$ was uncorrelated with BMI and weight, and minimally correlated with height in males and females ( $r = - 0.01$ , $p = 0.85$ and $r = 0.15$ , $p < 0.001$ ). The final $z (S M A_{HT})$ equation was: $z = (I - \hat{I}) / S D (I)$ , where $I = S M A / h e i g h t$ , $\hat{I} = 50 + B M I + 13 \times s e x + 0.6 \times B M I \times s e x$ , $S D (I) = 8.8 + 2.6 \times s e x$ , and sex = 1 if male, 0 if female. We propose $S M A_{HT}$ for optimal height adjustment and the $z (S M A_{HT})$ score for optimal height and BMI adjustment. By minimizing correlations with height and BMI, the $z (S M A_{HT})$ score produces unbiased assessments of relative L3 skeletal muscle area across the full range of body sizes.

2020

Gastroesophageal resuscitative occlusion of the aorta: Physiologic tolerance in a swine model of hemorrhagic shock.

Tiba MH, McCracken BM, Colmenero CI, Plott JS, Leander DC, Greer NL, Wang SC, Shih AJ, Eliason JL, Ward KR

J Trauma Acute Care Surg. 2020 Dec; 89(6):1114-1123.

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BACKGROUND:

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been shown to be effective for management of noncompressible torso hemorrhage. However, this technique requires arterial cannulation, which can be time-consuming and not amendable to placement in austere environments. We present a novel, less invasive aortic occlusion device and technique designated gastroesophageal resuscitative occlusion of the aorta (GROA). In this study, we aimed to characterize the physiological tolerance and hemodynamic effects of a prototype GROA device in a model of severe hemorrhagic shock and resuscitation and compare with REBOA.

METHODS:

Tee Y-S, Cheng C-T, Wu Y-T, Kang S-C, Derstine BA, Fu C-Y, Liao C-H, Su GL, Wang SC, Hsieh C-H.

Eur J Trauma Emerg Surg. 2020 Apr 10. [Online ahead of print] PMID: 32277250 DOI: 10.1007/s00068-020-01360-x

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BACKGROUND:

METHODS:

RESULTS:

Psoas muscle index was significantly higher in males (1065.09 ± 230.51 mm2/m2 in males vs 719.57 ± 147.39 mm2/m2 in females, p < 0.001) and decreased gradually with aging (p < 0.001). PMI of the subset of patients aged 18-40 (n = 462) weas analyzed to determine sex-specific cut-off values for ELPMI. PMI cut-off values for ELPMI (2 SD below mean) were 675 mm2/m2 for males and 490 mm2/m2 for females. The entire trauma cohort was further analyzed, and ELPMI was identified as an independent risk factor for a longer length of intensive unit stay (β coefficient = 3.881, p = 0.011).

CONCLUSIONS:

Data from young trauma adults were used to establish cut-off values for ELPMI, which is a longer ICU stay predictor. These cut-off values for ELPMI may apply to other acute disease entities.

2019

Morphomic Index Is an Independent Predictor of Survival After Lung Cancer Resection.

Ferguson MK, Mitzman B, Derstine B, Lee SM, Pienta MJ, Wang SC, Lin J.

Ann Thorac Surg. 2019 Dec 17;. doi: 10.1016/j.athoracsur.2019.10.064. [Epub ahead of print] PubMed PMID: 31862495.

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BACKGROUND:

Sarcopenia, visceral fat volume, and bone density have been associated with lung cancer survival. We developed a morphomic index based on computed tomographic measurements of these components, and assessed its relationship to survival after lung cancer resection.

METHODS:

Patients who underwent lung cancer resection from 1995 to 2014 were evaluated. A morphomic index (range of 0 to 3) was developed as the sum of the scores for three body components-dorsal muscle area, vertebral trabecular bone density, and visceral fat area-measured at vertebral levels T10 to T12, with a point assigned to each component when in the lowest tercile. The relationship of the morphomic index to overall survival was assessed by the log rank test. Overall survival was assessed using Cox proportional hazards models adjusted for relevant covariates.

RESULTS:

We included 944 patients (451 women; 48%). The mean age was 66.4 ± 10.3 years. Median follow-up was 4.5 years. Median survival was associated with the morphomic index scores on univariate analysis (P < .001). Morphomic index scores of 2 (P = .026) and 3 (P = .004) referenced to score 0 or 1 were independent predictors of survival on Cox regression analysis.

CONCLUSIONS:

A morphomic index is an independent predictor of survival after lung cancer resection. The index may help in calibrating patient expectations and in shared decision making regarding lung cancer surgery.

Comparison of Body Size, Morphomics, and Kidney Function as Covariates of High-Dose Methotrexate Clearance in Obese Adults with Primary Central Nervous System Lymphoma.

Pai MP, Debacker KC, Derstine B, Sullivan J, Su GL, Wang SC.

Pharmacotherapy. 2020 Feb 23;. doi: 10.1002/phar.2379. [Epub ahead of print] PubMed PMID: 32090349.

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BACKGROUND:

High-dose methotrexate (HD-MTX) is used to treat primary central nervous system lymphoma (PCNSL), but potential differences in MTX clearance (CL) due to obesity have not been studied. We characterized the relationship between HD-MTX CL and computed tomography (CT)-generated body composition (morphomic), body size descriptors, and laboratory measurements in a cohort of obese and non-obese patients with PCNSL.

METHODS:

Medical records from adult patients with PCNSL treated with HD-MTX over a 10-year period were queried. Individuals with CT data within 30 days of the first cycle of treatment were included. Population pharmacokinetic analysis was performed using a 2-compartment base structural model. We specifically compared body surface area (BSA) to standard body size, morphomic, and renal function estimation methods as covariates of HD-MTX CL.

RESULTS:

The final data set consisted of non-obese (n=45) and obese (n=28) patients with 291 observations (3-7 samples per patient) with a mean (standard deviation) weight of 69.8 (11.6) kg and 104 (14.9) kg, respectively (p=0.0001). Vertebral body height was more informative than BSA of MTX CL. Similarly, a CL model incorporating age, albumin, and serum creatinine was more informative than kidney function equations and body size. The final model of MTX CL was based on age, albumin, serum creatinine, and vertebral body height.

CONCLUSIONS:

Common clinical variables coupled with vertebral body height are more predictive of first cycle MTX CL than BSA, alternate body size descriptors, and commonly used kidney function equations.

Morphomic Factors Associated With Complete Response to Neoadjuvant Therapy in Esophageal Carcinoma.

Chiu CH, Zhang P, Chang AC, Derstine BA, Ross BE, Enchakalody B, Shah NV, Wang SC, Chao YK, Lin J.

Ann Thorac Surg.2020 Jan;109(1):241-248. doi: 10.1016/j.athoracsur.2019.08.031. Epub 2019 Sep 21. PubMed PMID: 31550463.

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BACKGROUND:

In patients undergoing neoadjuvant chemoradiotherapy (nCRT) followed by surgery for locally advanced esophageal squamous cell carcinoma (ESCC), patients with a pathologic complete response (pCR) have the greatest benefit. The purpose of this study was to identify morphomic factors obtained from pretreatment computed tomography scans associated with a pCR in ESCC.

METHODS:

We retrospectively analyzed patients with ESCC treated with nCRT who underwent esophagectomy between 2006 and 2016. Clinical and morphomic characteristics pre-nCRT were analyzed to identify factors associated with pCR using univariate and multivariable analyses.

RESULTS:

There were 183 patients with ESCC included in this study, and 45 (24.6%) patients achieved pCR. The overall survival in patients with pCR was better than that in patients without pCR (5.8 years vs 1.2 years; P < .001). On univariate analysis, increased age, radiation dose greater than or equal to 4000 cGy, and larger subcutaneous adipose tissue area were correlated with pCR. On multivariable logistic regression, increased age (odds ratio, 1.53; P = .03), radiation dose greater than or equal to 4000 cGy (odds ratio, 2.19; P = .04), and larger dorsal muscle group normal-density area (odds ratio, 1.59; P = .03) were independently associated with pCR.

CONCLUSIONS:

Increased age, radiation dose greater than or equal to 4000 cGy, and larger dorsal muscle group normal-density area were significantly associated with pCR. These factors may be useful in determining which patients are most likely to benefit from nCRT followed by esophagectomy.

Morphomic Signatures Derived from Computed Tomography Predict Hepatocellular Carcinoma Occurrence in Cirrhotic Patients.

Liang KH, Zhang P, Lin CL, Wang SC, Hu TH, Yeh CT, Su GL.

Dig Dis Sci. 2019 Nov 2; doi: 10.1007/s10620-019-05915-w. [Epub ahead of print] PubMed PMID: 31677071.

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BACKGROUND AND AIMS:

Computed tomography (CT) provides scans of the human body from which digitized features can be extracted. The aim of this study was to examine the role of these digital biomarkers for predicting subsequent occurrence of hepatocellular carcinoma (HCC) in cirrhotic patients.

METHODS:

A cohort of 269 patients with cirrhosis were recruited and prospectively followed for the occurrence of HCC in Taiwan. CT scans were retrospectively retrieved and computationally processed using analytic morphomics. A predictive score was constructed using Cox regression and the generalized iterative modeling method, maximizing the log likelihood of the time to HCC development. An independent cohort of 274 patients from University of Michigan was utilized to examine the predictive validity of this score in a Western population.

RESULTS:

Of the 27 digitized features at the 12th thoracic vertebral level, six features were significantly associated with HCC occurrence. Two digitized features (fascia eccentricity and the bone mineral density) were able to stratify patients into high- and low-risk groups with distinct cumulative incidence of HCC in both the training and validation cohorts (P = 0.015 and 0.044, respectively). When the two digitized features were tested in the Michigan cohort, only bone mineral density remained an effective predictor.

CONCLUSIONS:

Digitized features derived from the CT were effective in predicting subsequent occurrence of HCC in cirrhosis patients. The bone mineral density measured on CT was an effective predictor for patients in both Taiwan and USA.

Assessing Small Bowel Stricturing and Morphology in Crohn's Disease Using Semi-automated Image Analysis.

Stidham RW, Enchakalody B, Waljee AK, Higgins PDR, Wang SC, Su GL, Wasnik AP, Al-Hawary M.

Inflamm Bowel Dis. 2019 Aug 29;. doi: 10.1093/ibd/izz196. [Epub ahead of print] PubMed PMID: 31504540.

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BACKGROUND:

Evaluating structural damage using imaging is essential for the evaluation of small intestinal Crohn's disease (CD), but it is limited by potential interobserver variation. We compared the agreement of enterography-based bowel damage measurements collected by experienced radiologists and a semi-automated image analysis system.

METHODS:

Patients with small bowel CD undergoing a CT-enterography (CTE) between 2011 and 2017 in a tertiary care setting were retrospectively reviewed. CT-enterography studies were reviewed by 2 experienced radiologists and separately underwent automated computer image analysis using bowel measurement software. Measurements included maximum bowel wall thickness (BWT-max), maximum bowel dilation (DIL-max), minimum lumen diameter (LUM-min), and the presence of a stricture. Measurement correlation coefficients and paired t tests were used to compare individual operator measurements. Multivariate regression was used to model identification of strictures using semi-automated measures.

RESULTS:

In 138 studies, the correlation between radiologists and semi-automated measures were similar for BWT-max (r = 0.724, 0.702), DIL-max (r = 0.812, 0.748), and LUM-min (r = 0.428, 0.381), respectively. Mean absolute measurement difference between semi-automated and radiologist measures were no different from the mean difference between paired radiologists for BWT-max (1.26 mm vs 1.12 mm, P = 0.857), DIL-max (2.78 mm vs 2.67 mm, P = 0.557), and LUM-min (0.54 mm vs 0.41 mm, P = 0.596). Finally, models of radiologist-defined intestinal strictures using automatically acquired measurements had an accuracy of 87.6%.

CONCLUSIONS:

Structural bowel damage measurements collected by semi-automated approaches are comparable to those of experienced radiologists. Radiomic measures of CD will become an important new data source powering clinical decision-making, patient-phenotyping, and assisting radiologists in reporting objective measures of disease status.

Crash Telemetry-Based Injury Severity Prediction is Equivalent to or Out-Performs Field Protocols in Triage of Planar Vehicle Collisions.

He K, Zhang P, Wang SC.

Prehosp Disaster Med. 2019 Aug;34(4):356-362. doi: 10.1017/S1049023X19004515. Epub 2019 Jul 19. PubMed PMID: 31322099.

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INTRODUCTION:

With the increasing availability of vehicle telemetry technology, there is great potential for Advanced Automatic Collision Notification (AACN) systems to improve trauma outcomes by detecting patients at-risk for severe injury and facilitating early transport to trauma centers.

METHODS:

National Automotive Sampling System Crashworthiness Data System (NASS-CDS) data from 1999-2013 were used to construct a logistic regression model (injury severity prediction [ISP] model) predicting the probability that one or more occupants in planar, non-rollover motor vehicle collisions (MVCs) would have Injury Severity Score (ISS) 15+ injuries. Variables included principal direction of force (PDOF), change in velocity (Delta-V), multiple impacts, presence of any older occupant (≥55 years old), presence of any female occupant, presence of right-sided passenger, belt use, and vehicle type. The model was validated using medical records and 2008-2011 crash data from AACN-enabled Michigan (USA) vehicles identified from OnStar (OnStar Corporation; General Motors; Detroit, Michigan USA) records. To compare the ISP to previously established protocols, a literature search was performed to determine the sensitivity and specificity of first responder identification of ISS 15+ for MVC occupants.

RESULTS:

The study population included 924 occupants in 836 crash events. The ISP model had a sensitivity of 72.7% (95% Confidence Interval [CI] 41%-91%) and specificity of 93% (95% CI 92%-95%) for identifying ISS 15+ occupants injured in planar MVCs. The current standard 2006 Field Triage Decision Scheme (FTDS) was 56%-66% sensitive and 75%-88% specific in identifying ISS 15+ patients.

CONCLUSIONS:

The ISP algorithm comparably is more sensitive and more specific than current field triage in identifying MVC patients at-risk for ISS 15+ injuries. This real-world field study shows telemetry data transmitted before dispatch of emergency medical systems can be helpful to quickly identify patients who require urgent transfer to trauma centers.

CT Correlation of Skeletal Landmarks and Vascular Anatomy in Civilian Adult Trauma Patients Implications for Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA).

Eliason J L, Derstine BA, Horbal SR, Wang NC, Holcombe SA, Chiu C-H, Ross BE, Bromwell B, Morrison J, Wang SC.

J Trauma Acute Care Surg: Mar 1, 2019. Vol Pub Ahead of Print Issue doi: 10.1097/TA.0000000000002247.

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BACKGROUND:

REBOA is a valuable resuscitative adjunct in a variety of clinical settings. In resource-limited or emergency environments, REBOA may be required with delayed or absent image-guidance or verification. Catheter insertion lengths may be informed by making CT correlations of skeletal landmarks with vascular lengths.

METHODS:

2247 trauma patients with CT imaging between 2000-2015 at a single civilian tertiary care center were identified, yielding 1789 patients with adequate contrast opacification of the arterial system in the chest, abdomen, and pelvis. Individual scans were analyzed using MATLAB software, with custom high-throughput image processing algorithms applied to correlate centerline vascular anatomy with musculoskeletal landmarks. Data were analyzed using R version 3.3.

RESULTS:

The median centerline distance from the skin access to the aortic bifurcation was longer by 0.3 cm on the right than on the left side. Median Aortic Zone I length was 21.6 (IQR, 20.3-22.9) cm, while Zone III was 8.7 (7.8-9.5) cm. Torso extent (TE) correlation to Zone I was much higher than for Zone III (R2 0.58 vs 0.26 (right) and 0.58 vs. 0.27 (left), p<0.001). Assuming a 4 cm balloon length, optimal fixed insertion length would be 48 cm and 28 cm for Zones I and III (Error 0.4% vs 33.3%), respectively, although out of zone placements can be reduced if adjusted for TE (Error 0% vs 26.4%).

CONCLUSIONS:

CT morphometry suggests a fixed REBOA catheter insertion length of 48 cm for Zone I and 28 cm for Zone III is optimal (on average, for average-height individuals), with improved accuracy by formulaic adjustments for torso extent. High residual error for Zone III placement may require redesign of existing catheter balloon lengths or consideration of the relative risk associated with placing the balloon catheter too low or too high.

An Anatomic Indexing System for Costal Cartilage and Its Application in Calcification Representation in Finite-Element Human Body Models.

Huang Y, Zhou Q, Wang SC, Nie BB, Holcombe SA.

International Research Council on Biomechanics of Injury, IRC-19-32.

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Costal cartilage plays an important role in the structural stiffness of the ribcage as segments that flexibly connect the bony ribs to the sternum. Calcification of costal cartilage occurring throughout adult life can substantially change local material properties and stiffen the structural mechanical response. Current finite element (FE) human body models (HBMs) have a simplified representation of costal cartilage with homogeneous material properties, yet the FE meshes allow for discrete regions within a given mesh to be modeled using separate materials. To represent costal cartilage and its calcification across the population, this study proposed a consistent indexing system shared between HBMs as well as the real humans they represent. In this system, spatial positions in the costal cartilage are identified using a continuous coordinate space. This study also proposed a modeling framework to represent costal cartilage calcification in multiple models in a consistent fashion with real human data. This study successfully applied the indexing system to several current commercial FE HBMs and tested the ability of the framework with a limited set of real human data. The indexing system and modeling framework are expected to be a precursor to future study on the influence of calcification on mechanical responses of the ribcage.

Computed Tomography Evidence of Psoas Muscle Atrophy Without Concomitant Tendon Wasting in Early Sepsis.

Kubiak CA, Ranganathan K, Matusko N, Jacobson JA, Wang SC, Park PK, Levi BL.

J Surg Res. 2019 Feb;234:210-216. doi: 10.1016/j.jss.2018.09.010. Epub 2018 Oct 11. PubMed PMID: 30527476.

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BACKGROUND:

Morphomic studies have demonstrated a correlation between sarcopenia and clinical outcomes in septic patients. However, tendon morphomics has not yet been studied in this context. The purpose of the present study was to evaluate tendon morphology in septic patients through analytic morphomics. We hypothesized that morphomic analyses would reveal concomitant muscle and tendon wasting in sepsis patients. The results of this study may help to implement different rehabilitation modalities for critically ill patients.

MATERIALS AND METHODS:

STUDY DESIGN:

The Michigan Surgical and Health Optimization Program (MSHOP) is a formal prehabilitation program that engages patients in 4 activities before surgery: physical activity, pulmonary rehabilitation, nutritional optimization, and stress reduction. We prospectively collected demographic, intraoperative (first hour), and postoperative data for patients enrolled in MSHOP undergoing major abdominal surgery. Statistical analysis was performed using 2:1 propensity score matching to compare the MSHOP group (n = 40) to emergency (n = 40) and elective, non-MSHOP (n = 76) patients.

RESULTS:

Overall, 70% of MSHOP patients complied with the program. Age, sex, American Society of Anesthesiologists (ASA) classification, and BMI did not differ significantly between groups. One hour intraoperatively, MSHOP patients showed improved systolic and diastolic blood pressures and lower heart rate (Figure). There was a significant reduction in Clavien-Dindo class 3 to 4 complications in the MSHOP group (30%) compared with the nonprehabilitation (38%) and emergency (48%) groups (p = 0.05). This translated to total hospital charges averaging $75,494 for the MSHOP group, $97,440 for the nonprehabilitation group, and $166,085 for the emergency group (p < 0.001).

CONCLUSIONS:

Patients undergoing prehabilitation before colectomy showed positive physiologic effects and experienced fewer complications. The average savings of $21,946 per patient represents a significant cost offset for a prehabilitation program, and should be considered for all patients undergoing surgery.

2018

Morphomic Malnutrition Score: A Standardized Screening Tool for Severe Malnutrition in Adults.

Lee C, Raymond E, Derstine BA, Glazer JM, Goulson R, Rajasekaran A, Cherry‐Bukowiec J, Su GL, Wang SC.

JPEN J Parenter Enteral Nutr. 2018 May 22. doi: 10.1002/jpen.1175. [Epub ahead of print] PubMed PMID: 29786877.

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BACKGROUND:

Granular diagnostic criteria for adult malnutrition are lacking.

OBJECTIVE:

This study uses analytic morphomics to define the Morphomic Malnutrition Score (MMS), a robust screening tool for severe malnutrition.

METHODS:

The study population (n = 643) consisted of 2 cohorts: 1) 124 emergency department patients diagnosed with severe malnutrition by a registered dietitian (RD) and an available computed tomography (CT) scan within 2 days of RD evaluation, and 2) 519 adult kidney donor candidates to represent a healthy cohort. Body composition markers of muscle area and abdominal adiposity were measured from patient CT scans using analytic morphomic assessment, and then converted to sex- and age-adjusted percentiles using the Reference Analytic Morphomics Population (RAMP). RAMP consists of 6000 patients chosen to be representative of the general population. The combined cohort was then randomly divided into training (n = 453) and validation (n = 190) sets. MMS was derived using logistic regression. The model coefficients were transformed into a score, normalized from 0 to 10 (10 = most severe).

RESULTS:

Severely malnourished patients had lower amounts of muscle and fat than kidney donors, specifically for dorsal muscle group area at the twelfth thoracic vertebral level (P < 0.001), psoas muscle area at the fourth lumbar vertebral level (P < 0.001), and subcutaneous fat area at the third lumbar vertebral level (P < 0.001)-all parameters in MMS. MMS for severely malnourished patients was higher than kidney donors (7.7 ± 2.2 vs 3.8 ± 2.0, respectively; P-value < 0.001). An MMS > 6.1 was accurate in determining nutrition diagnosis (82.1% sensitivity; 88.3% specificity; 85.2% balanced accuracy).

CONCLUSIONS:

MMS provides an evidence-based, granular assessment to distinguish severely malnourished adults from a healthy population.

Measuring rib cortical bone thickness and cross section from CT.

Holcombe SA, Hwang E, Derstine BA, Wang SC.

Med Image Anal. 2018 Oct;49:27-34. Doi: 10.1016/j.media.2018.07.003. Epub 2018 Jul 10. PubMed PMID: 30031288.

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This study assesses the ability to measure local cortical bone thickness, and to obtain mechanically relevant properties of rib cross-sections from clinical-resolution computed tomography (CT) scans of human ribs. The study utilized thirty-four sections of ribs published by Perz et al. (2015) in three modalities: standard clinical CT (clinCT), high-resolution clinical CT (HRclinCT), and microCT (µCT). Clinical-resolution images were processed using a Cortical Bone Mapping (CBM) algorithm applied to cross-cortex signals resampled perpendicularly to an initial smooth periosteal border. Geometric constraints were applied to remove outlier signals from consideration, and final predicted periosteal and endosteal borders from HRclinCT and clinCT were developed. Target values for local cortical thickness and for overall cross-sectional area and inertial properties were obtained from segmentation of the periosteal and endosteal borders on each corresponding µCT image. Errors in prediction (mean ± SD) of local cortical bone thickness for HRclinCT and clinCT resolutions were -0.03±0.17 mm and -0.05±0.22 mm, respectively, with R2 coefficients of determination from linear regression of 0.82 and 0.71 (p < 0.0001 for both). Predicted cortical shell measures derived from the periosteal and endosteal borders included total cross-sectional area (prediction errors of 6 ± 3% and -1±5% respectively for HRclinCT and clinCT with R2 correlations of 0.99 and 0.96), cortical shell area (errors of -3±8% and -8±11% with R2 correlations of 0.91 and 0.87), and principal area moment of inertia (errors of 2 ± 8% and -3±11% with R2 correlations of 0.98 and 0.95). Results here show substantial reductions in rib cross-sectional measurement error compared to past histogram-based thresholding methods and provide first validation of the CBM method when applied to rib bones. With the ubiquity of clinical CT scans covering the thorax and ribs, this study opens the door for individualized and population-wide quantification of rib structural properties and their corresponding effects on rib injury.

Thoracolumbar Spine Fracture occurring in Obese People involved in Motor Vehicle Crashes.

Ejima S, Holcombe SA, Zhang PC, Derstine BA, Goulson RL, MacWilliams J, Kohoyda-Inglis CJ, Wang SC.

International Research Council on the Biomechanics of Impact. 2018 September; :157-166.

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Crash data from the International Center of Automotive Medicine (ICAM) database, with analytic morphomics, were used to evaluate thoracolumbar spine fractures for obese occupants in frontal crashes. Two BMI (Body Mass Index) groups (non‐obese and obese) with a maximum abbreviated injury scale (MAIS) in the spine region of >2 (MAIS-6S 2+) were categorised and compared. The fracture types were assessed based on AIS for each occupant. Univariate analyses were conducted to investigate the association between analytic morphomics measures and thoracolumbar spine fracture. The results indicate that MAIS 2+ injury occurred mainly in severe crashes with high delta‐V and large intrusion. Transverse process fractures were the most common AIS 2+ fractures, followed by minor compression type fractures (≤ 20% anterior height). Compared to the non‐obese occupants, the majority of obese occupants sustained transverse process fractures at lumbar vertebra with a higher incidence ratio. A statistical analysis was conducted, using vehicle, demographic, and morphomic variables, to explain the difference between transverse process fractures and vertebra body compression fractures. Transverse process fractures were related to BMI and vehicle factors (intrusion) in the obese group. In addition, morphomics related to fat distribution, muscle area, and cortical bone density are the major difference between non‐obese and obese occupants.

Skeletal muscle cutoff values for sarcopenia diagnosis using T10 to L5 measurements in a healthy US population.

Derstine BA, Holcombe SA, Ross BE, Wang NC, Su GL, Wang SC

Sci Rep. 2018 Jul 27;8(1):11369. doi: 10.1038/s41598-018-29825-5. PubMed PMID: 30054580; PubMed Central PMCID: PMC6063941.

Pienta MJ, Zhang P, Derstine BA, Enchakalody B, Weir WB, Grenda T, Goulson R, Reddy RM, Chang AC, Wang SC, Lin J.

Ann Thorac Surg. 2018 Feb;105(2):399-405. doi: 10.1016/j.athoracsur.2017.08.049. Epub 2017 Dec 2. PubMed PMID: 29198627; PubMed Central PMCID: PMC5783736.

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BACKGROUND: The purpose of this study was to identify morphomic factors on standard, pretransplantation computed tomography (CT) scans associated with outcomes after lung transplantation.

METHODS: A retrospective review of 200 patients undergoing lung transplantation at a single institution from 2003 to 2014 was performed. CT scans obtained within 1 year before transplantation underwent morphomic analysis. Morphomic characteristics included lung, dorsal muscle group, bone, and subcutaneous and visceral fat area and density. Patient data were gathered from institutional and United Network for Organ Sharing databases. Outcomes, including initial ventilator support greater than 48 hours, length of stay, and survival, were evaluated using univariate and multivariable analyses.

RESULTS: On multivariable Cox regression, subcutaneous fat/total body area (hazard ratio [HR] 0.60, p = 0.001), lung density 3 volume (HR 0.67, p = 0.013), and creatinine (HR 4.37, p = 0.010) were independent predictors of survival. Initial ventilator support more than 48 hours was associated with decreased vertebral body to linea alba distance (odds ratio [OR] 0.49, p = 0.002) and Zubrod score 4 (OR 14.0, p < 0.001). Increased bone mineral density (p < 0.001) and increased cross-sectional body area (p < 0.001) were associated with decreased length of stay, whereas supplemental oxygen (p < 0.001), bilateral transplantation (p = 0.002), cardiopulmonary bypass (p < 0.001), and Zubrod score 3 (p < 0.001) or 4 (p = 0.040) were associated with increased length of stay.

CONCLUSIONS: Morphomic factors associated with lower metabolic reserve and frailty, including decreased subcutaneous fat, bone density, and body dimensions were independent predictors of survival, prolonged ventilation, and increased length of stay. Analytic Morphomics® using pretransplantation CT scans may improve recipient selection and risk stratification.

2017

Quantifying Sarcopenia Reference Values Using Lumbar and Thoracic Muscle Areas in a Healthy Population.

Derstine BA, Holcombe SA, Goulson RL, Ross BE, Wang NC, Sullivan JA, Su GL, Wang SC.

J Nutr Health Aging. 2017;21(10):180-185. doi: 10.1007/s12603-017-0983-3.

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BACKGROUND: Sarcopenia is defined as the loss of skeletal muscle mass and function associated with aging. Muscle mass can be reliably and accurately quantified using clinical CT scans but reference measurements are lacking, particularly in healthy US populations.

METHODS: Two-phase CT scans from healthy kidney donors (age 18-40) at the University of Michigan between 1999-2010 were utilized. Muscle mass was quantified using two thoracic and two lumbar muscle cross-sectional area (CSA) measures. Indexed measurements were computed as area divided by height-squared. Paired analyses of non-contrast and contrast phases and different Hounsfield Unit (HU) ranges for muscle were conducted to determine their effect on CSA muscle measures. We report the means, standard deviations, and 2SD sarcopenia cutoffs from this population.

RESULTS: Healthy population CSA (cm2) cutoffs for N=604 males/females respectively were: 34.7/20.9 (T12 Dorsal Muscle), 91.5/55.9 (T12 Skeletal Muscle), 141.7/91.2 (L3 Skeletal Muscle), 23.5/14.3 (L4 Total Psoas Area), and 23.4/14.3 (L4 Psoas Muscle Area). Height-indexed CSA (cm2/m2) cutoffs for males/females respectively were: 10.9/7.8 (T12 Dorsal Muscle), 28.7/20.6 (T12 Skeletal Muscle), 44.6/34.0 (L3 Skeletal Muscle), 7.5/5.2 (L4 Total Psoas Area), and 7.4/5.2 (L4 Psoas Muscle Area). We confirmed that a mask of -29 to 150 HU is optimal and shows no significant difference between contrast-enhanced and non-contrast CT scan CSA measurements.

CONCLUSIONS: We quantified reference values for lumbar and thoracic muscle CSA measures in a healthy US population. We defined the effect of IV contrast and different HU ranges for muscle. Combined, these results facilitate the extraction of clinically valuable data from the large numbers of existing scans performed for medical indications.

Calcification of costal cartilage in the adult rib cage

248. Holcombe SA, Wang SC.

The 2017 IRCOBI Conference, Proceedings of the 2017 International Research Council on the Biomechanics of Impact.

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ABSTRACT: Costal cartilage bridges the sternum and the ribs and plays a key role in the biomechanics of the chest. Costal cartilage is known to calcify in local regions with age, which can substantially stiffen its overall response to loading. However, the rate of accumulation of the calcified volume is not well quantified. Current computational models of the thorax assign a homogeneous soft material to cartilage segments, yet their finite element meshes are well suited to the specification of interstitial calcification zones, should applicable data become available.

This study measures volumes and extents of costal cartilage calcification from 205 live subject CT scans. Significant increases in volume calcification – both in a given cartilage segment and in the lengthwise extent of those segments that experience calcification – are seen with age (p<0.0001). Age and sex accounted for 35% of all inter‐individual population variability. Specific recommendations for introducing person‐age via regional calcification to models of the costal cartilage are that (1) calcification volume within a segment should increase at the rate of 0.9 mm (for an equivalent cube edge length) per decade, and (2) should involve an increasing lengthwise extent of the cartilage segment at a rate of at least 7% per decade.

The Effect of Rib Fracture Pattern in the Obese

Ejima S, Holcombe SA, Zhang P, Derstine BA, Goulson RL, MacWilliams J, Kohoyda-Inglis C, Wang SC.

The 2017 IRCOBI Conference, Proceedings of the 2017 International Research Council on the Biomechanics of Impact.

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ABSTRACT: In this study, Analytic Morphomics® is applied to understand rib fractures in obese occupants in frontal and nearside crashes. Rib fracture patterns were examined in occupants involved in crashes from the International Center for Automotive Medicine database. Among these occupants, two BMI groups (nonobese and obese) with a maximum abbreviated injury scale in the chest region of > 3 (MAISthx3+) were categorized and compared. Univariate analyses were conducted for the BMI groups to compare the rib fracture incidence ratio in each rib and occupant factors based on morphomics variables. In frontal crashes, rib fractures were mainly located under the path of shoulder belt. For the obese group, fracture patterns tended to be located on the lower ribs (#6-8). In the nearside crashes, rib fractures were located in the lateral and posterior regions. For the obese group, fracture patterns tended to be located more laterally rather than posteriorly. Morphomics related to rib angle, fat in the back, and subcutaneous fat are the major differences between the groups. The current results for rib orientation and fat distribution can highlight the importance of considering these morphomics characteristics when assessing chest injury and creating obese computer models.

Second generation AACN injury severity prediction algorithm: development and real-world validation

Wang SC, Kohoyda-Inglis C, Ejima S, MacWilliams JB, Zhang P, Stacey L, Melocchi A, Gorman D, Kral J., Joyner, J.

Proceedings of 25th International Technical Conference on Enhanced Safety of Vehicles (ESV), Detroit, Michigan. June 2017. Paper No. 17-0133.

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ABSTRACT: Advanced automatic collision notification(AACN)based injury severity prediction (ISP) has great potential to improve post-crash care.The national Expert Panel for Field Triage set 20% risk of Injury Severity Score (ISS) 15+ injury as the threshold for urgent transport to a trauma center.Earlier, we published an Injury Severity Prediction algorithm (ISP v1) that was developed using data from the National Automotive Sampling System Crashworthiness Data System (NASS_CDS) for the calendar years 1999-2008.In a field trialpublished at ESV 2015,this ISP algorithm version 1 demonstratedbetter than predicted sensitivity to detect seriously injured (ISS15+) crash occupants.In the current study, wesought to a) update the ISP algorithm using more current NASS-CDS data, b) improve predictive accuracy by refining the granularity of the input data, and c)validate the ability of this updated algorithm (ISP v2) using real-world crash cases involving GM vehicles equipped with OnStar.

NASS-CDS data (1999-2013) was used to develop a functional logistic regression model to predict the probability that a crash-involved vehicle would contain one or more occupants with ISS15+ injuries in planar, non-rollover crash events involving Model Year 2000 and newercars, light trucks, and vans. Two of the parameters used in the original ISP algorithm were modified (principal direction of force [PDOF], older occupant age) and a new parameter was created and involved the presence of a right-sided passenger.This study was approved by the IRB of the Michigan Department of Health and Human Services (formerly the Michigan Department of Community Health). The initial 924 occupants in 836 crashes published in the 2015 study were again opened for review and injury severity predictions from the updated algorithm werecompared to the observed injury outcomes.

The updated ISP v2, which employs the functional data analysis technique to model the effect of PDOF to ISS 15+ injury as a continuous cyclic function, showed an improved predictive performance (AUC 0.872, AIC 2370) over the original ISP v1 (AUC 0.865, AIC 2377) that used only 4 crash directions. The original elderly age cutoff of 55 performed better than an age cutoff of 60, so age ≥55 was retained as a parameter in ISP v2.Using field data for validation, the updated ISP algorithm had significantly improved sensitivity for detecting seriously injured (ISS15+) occupants (72.7% vs. 63.4%) with minimal changes in specificity (93% vs 94%). The AUROC for ISP v2 was 0.946, an improvement over the AUROC for ISP v1 (AUROC 0.932).

This study confirms under real world field conditions that occupant injury severity can be predicted using vehicle telemetry data. The updated ISPv2algorithm’s ability to predict a 20% or greater risk of severe (ISS15+) injury confirms ISP’s utility for the field triage of crash subjects.

Relationships of Vancomycin Pharmacokinetics to Body Size and Composition Using a Novel Pharmacomorphomic Approach Based on Medical Imaging.

Pai MP, Derstine BA, Lichty M, Ross BE, Sullivan JA, Su GL, Wang SC.

Antimicrob Agents Chemother. 2017 Oct 24;61(11). pii: e01402-17. doi: 10.1128/AAC.01402-17. Print 2017 Nov. PubMed PMID: 28807918; PubMed Central PMCID: PMC5655058.

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Abstract

Antibiotics such as vancomycin are empirically dosed on the basis of body weight, which may not be optimal across the expanding adult body size distribution. Our aim was to compare the relationships between morphomic parameters generated from computed tomography images to conventional body size metrics as predictors of vancomycin pharmacokinetics (PK). This single-center retrospective study included 300 patients with 1,622 vancomycin concentration (52% trough) measurements. Bayesian estimation was used to compute individual vancomycin volume of distribution of the central compartment (Vc) and clearance (CL). Approximately 45% of patients were obese with an overall median (5th, 95th percentile) weight and body mass index of 87.2 (54.7, 123) kg and 28.8 (18.9, 43.7) kg/m2, respectively. Morphomic parameters of body size such as body depth, total body area, and torso volume of the twelfth thoracic through fourth lumbar vertebrae (T12 to L4) correlated with Vc. The relationship of vancomycin Vc was poorly predicted by body size but was stronger with T12-to-L4 torso volume (coefficient of determination [R2] = 0.11) than weight (R2 = 0.04). No relationships between vancomycin CL and traditional body size metrics could be discerned; however, relationships with skeletal muscle volume and total psoas area were found. Vancomycin CL independently correlated with total psoas area and inversely correlated with age. Thus, vancomycin CL was significantly related to total psoas area over age (R2 = 0.23, P < 0.0001). This proof-of-concept study suggests a potential role for translation of radiographic information into parameters predictive of drug pharmacokinetics. Prediction of individual antimicrobial pharmacokinetic parameters using Analytic Morphomics® has the potential to improve antimicrobial dose selection and outcomes of obese patients.

The 'Cushion Effect' Is Not Protective for Children Involved in Motor Vehicle Crashes.

Calista Harbaugh, MD, Brianna Henderson, Peng Zhang, PhD, Brian Derstine, Sven A. Holcombe, PhD, Stewart Wang, MD, PhD, Peter F. Ehrlich, MD, FACS

Journal of the American College of Surgeons, October 2017. Volume 225, Issue 4, e187 - e188

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Abstract

INTRODUCTION: Analytic Morphomics® (AM) applies computational image processing algorithms to cross-sectional images to perform detailed measurements on morphological features in 3D space. In adults, data suggests that body composition can impact the risk and pattern of injury in motor vehicle crashes (MVC) with increased BMI protecting against abdominal injuries and pelvic fractures. This is known as the "cushion effect." The purpose of this study is to examine the impact of the "cushion effect" on thoracic, abdominal and spine injuries in children involved in frontal MVC.

METHODS: Retrospective chart review and AM were performed on 617 patients admitted to the University of Michigan after MVC. Injury severity was assessed using maximum abbreviated injury score (MAIS) and crash impact rating was derived from crash reporting forms (UD-10). AM measures included visceral fat cross-sectional area, subcutaneous fat cross-sectional area, trabecular bone density and psaos muscle area at L4 vertebral level.

RESULTS: Of the 617 MVC, 212 were frontal crashes and included in the study. The population was 45% male with average age 12.4 ± 5.0 years. Sex, age and impact rating did not correlate with MAIS. Subcutaneous fat cross-sectional area, visceral fat cross-sectional area, bone density and psoas muscle area did not correlate with injury severity for MAIS 2+ abdominal, thoracic or spinal injuries.

CONCLUSIONS: Though subcutaneous fat has previously correlated with decreased abdominal and pelvic injury in adults, this study shows that subcutaneous fat does not impact the risk of thoracic, abdominal or spine injuries in children involved in frontal crashes.

Morphometric age and survival following kidney transplantation.

Terjimanian MN, Underwood PW, Cron DC, Augustine JJ, Noon KA, Cote DR, Wang SC, Englesbe MJ, Woodside KJ.

Clin Transplant. 2017 Oct;31(10). doi: 10.1111/ctr.13066. Epub 2017 Aug 28. Erratum in: Clin Transplant. 2017 Dec 16;:. PubMed PMID: 28758236.

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BACKGROUND: As patients with chronic kidney disease become older, there is greater need to identify who will most benefit from kidney transplantation. Analytic Morphomics® has emerged as an objective risk assessment tool distinct from chronologic age. We hypothesize that morphometric age is a significant predictor of survival following transplantation.

METHODS: A retrospective cohort of 158 kidney transplant patients from 2005 to 2014 with 1-year preoperative imaging was identified. Based on a control population comprising of trauma patients and kidney donors, morphometric age was calculated using the validated characteristics of psoas area, psoas density, and abdominal aortic calcification. The primary outcome was post-transplant survival.

RESULTS: Cox regression showed morphometric age was a significant predictor of survival (hazard ratio, 1.06 per morphometric year [95% confidence interval, 1.03-1.08]; P < .001). Chronological age was not significant (hazard ratio, 1.03 per year [0.98-1.07]; P = .22). Among the chronologically oldest patients, those with younger morphometric age had greater survival rates compared to those with older morphometric age.

CONCLUSIONS: Morphometric age predicts survival following kidney transplantation. Particularly for older patients, it offers improved risk stratification compared to chronologic age. Morphomics may improve the transplant selection process and provide a greater assessment of prospective survival benefits.

Using Analytic Morphomics® to describe body composition associated with post-kidney transplantation diabetes mellitus.

Cron DC, Noon KA, Cote DR, Terjimanian MN, Augustine JJ, Wang SC, Englesbe MJ, Woodside KJ.

Clin Transplant. 2017 Sep;31(9). doi: 10.1111/ctr.13040. Epub 2017 Jul 20. PubMed PMID: 28640481.

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BACKGROUND: Better risk assessment tools are needed to predict post-transplantation diabetes mellitus (PTDM). Using analytic morphomic measurements from computed tomography (CT) scans, we aimed to identify specific measures of body composition associated with PTDM.

METHODS: We retrospectively reviewed 99 non-diabetic kidney transplant recipients who received pre-transplant CT scans at a single institution between 1/2005 and 5/2014. Analytic morphomic techniques were used to measure abdominal adiposity, abdominal size, and psoas muscle area and density, standardized by gender. We measured the associations of these morphomic factors with PTDM.

RESULTS: One-year incidence of PTDM was 18%. The morphomic factors significantly associated with PTDM included visceral fat area (OR=1.84 per standard deviation increase, P=.020), body depth (OR=1.79, P=.035), and total body area (OR=1.67, P=.049). Clinical factors significantly associated with PTDM included African American race (OR=3.01, P=.044), hypertension (OR=2.97, P=.041), and dialysis vintage (OR=1.24 per year on dialysis, P=.048). Body mass index was not associated with PTDM (OR=1.05, P=.188). On multivariate modeling, visceral fat area was an independent predictor of PTDM (OR=1.91, P=.035).

CONCLUSIONS: Analytic Morphomics® can identify pre-transplant measurements of body composition that are predictive of PTDM in kidney transplant recipients. Pre-transplant imaging contains a wealth of underutilized data that may inform PTDM prevention strategies.

Dorsal Muscle Attenuation May Predict Failure to Respond to Interleukin-2 Therapy in Metastatic Renal Cell Carcinoma.

Otemuyiwa B, Derstine BA, Zhang P, Wong SL, Sabel MS, Redman BG, Wang SC, Alva AS, MS.

Acad Radiol. 2017 Sep;24(9):1094-1100. doi: 10.1016/j.acra.2017.03.003. Epub 2017 Mar 22. PubMed PMID: 28341412

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RATIONALE AND OBJECTIVES: To explore whether the sarcopenia body type can help predict response to interleukin-2 (IL-2) therapy in metastatic renal cell carcinoma (RCC).

MATERIALS AND METHODS: Institutional review board approval was obtained for this Health Insurance Portability and Accountability Act-compliant retrospective cohort study of 75 subjects with metastatic RCC who underwent pretreatment contrast-enhanced computed tomography within 1 year of initiating IL-2 therapy. Cross-sectional area and attenuation of normal-density (31-100 Hounsfield units [HU]) and low-density (0-30 HU) dorsal muscles were obtained at the T11 vertebral level. The primary outcome was partial or complete response to IL-2 using RECIST 1.1 criteria at 6 weeks. A conditional inference tree was used to determine an optimal HU cutoff for predicting outcome. Bonferroni-adjusted multivariate logistic regression was conducted to investigate the independent associations between imaging features and response after controlling for demographics, doses of IL-2, and RCC prognostic scales (eg, Heng and the Memorial Sloan Kettering Cancer Center [MSKCC]).

RESULTS: Most subjects had intermediate prognosis by Heng (65% [49 of 75]) and the MSKCC (63% [47 of 75]) criteria; 7% had complete response and 12% had partial response. Mean attenuation of low-density dorsal muscles was a significant univariate predictor of IL-2 response after Bonferroni correction (P = 0.03). The odds of responding to treatment were 5.8 times higher for subjects with higher-attenuation low-density dorsal muscles (optimal cutoff: 18.1 HU). This persisted in multivariate analysis (P = 0.02). Body mass index (P = 0.67) and the Heng (P = 0.22) and MSKCC (P = 0.08) clinical prognostic scales were not significant predictors of response.

CONCLUSIONS: Lean cross-sectional attenuation of low-density dorsal muscles (ie, sarcopenia) may predict IL-2 response in metastatic RCC. Clinical variables are poor predictors of response.

The effect of age and demographics on rib shape

Holcombe SA, Wang SC, Grotberg JB

J Anat. 2017 Aug;231(2):229-247. doi: 10.1111/joa.12632. Epub 2017 Jun 13. PubMed PMID: 28612467.

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INTRODUCTION

Elderly populations have a higher risk of rib fractures and other associated thoracic injuries than younger adults, and the changes in body morphology that occur with age are a potential cause of this increased risk. Rib centroidal path geometry for 20,627 ribs was extracted from computed tomography (CT) scans of 1042 live adult subjects, then fitted to a six-parameter mathematical model that accurately characterizes rib size and shape, and a three-parameter model of rib orientation within the body. Multivariable regression characterized the independent effect of age, height, weight, and sex on the rib shape and orientation across the adult population, and statistically significant effects were seen from all demographic factors (P < 0.0001). This study reports a novel aging effect whereby both the rib end-to-end separation and rib aspect ratio are seen to increase with age, producing elongated and flatter overall rib shapes in elderly populations, with age alone explaining up to 20 percent of population variability in the aspect ratio of mid-level ribs. Age was not strongly associated with overall rib arc length, indicating that age effects were related to shape change rather than overall bone length. The rib shape effect was found to be more strongly and directly associated with age than previously documented age-related changes in rib angulation. Other demographic results showed height and sex being most strongly associated with rib size, and weight most strongly associated with rib pump-handle angle. Results from the study provide a statistical model for building rib shapes typical of any given demographic by age, height, weight, and sex, and can be used to help build population-specific computational models of the thoracic rib cage. Furthermore, results also quantify normal population ranges for rib shape parameters which can be used to improve the assessment and treatment of rib skeletal deformity and disease.

Body Composition Predicts Survival in Patients with Hepatocellular Carcinoma Treated with Transarterial Chemoembolization.

Parikh ND, Zhang P, Singal AG, Derstine BA, Krishnamurthy V, Barman P, Waljee AK, Su GL

Cancer Res Treat. 2018 Apr;50(2):530-537. doi: 10.4143/crt.2017.156. Epub 2017 Jun 1.

This retrospective study population contains 2591 individual CT scans of a normative reference population of males and females (1-20years old). Growth curves were constructed at the 5th, 25th, 50th, 75th, and 95th quantiles for morphomic variables, including psoas muscle area, trabecular bone density, and visceral fat area by age and gender.

RESULTS

Total psoas muscle area increases over time until late adolescence. Trabecular bone density remains stable until adolescence, decreases during adolescence, and increases in young adulthood. Visceral fat area increases over time with greater variation between the 5th and 95th percentile with increasing age.

CONCLUSIONS

The PRAMP™ data have been used to construct age- and sex-specific reference growth curves. This may be used to better define "abnormal" in efforts to create unique risk-categorization algorithms specific to particular clinical and global health investigations.

LEVEL OF EVIDENCE

Level II

Ranganathan K, Agarwal S, Cholok D, Loder S, Li J, Sung Hsieh HH, Wang SC, Buchman SR, Levi B.

J Surg Res. 2016 Nov;206(1):53-61. doi: 10.1016/j.jss.2016.04.040. Epub 2016 Jul 13.

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BACKGROUND

Luckenbaugh AN, Hollenbeck BK, Montgomery JS, Lee CT, Gilbert SM, Dunn RL, Friedman JF, Englesbe MJ, Wang SC, Hollingsworth JM

Bladder Cancer. 2016 Apr 27;2(2):235-240.

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BACKGROUND

Data from the general surgery literature suggests that patient morphometric data obtained from preoperative imaging may help predict a patient's risk around surgery.

OBJECTIVES

In this context, we evaluated for associations between psoas muscle area and short-term convalescence following radical cystectomy.

METHODS

After identifying patients who underwent radical cystectomy at our institution (2008 to 2013), we calculated their psoas muscle area from staging computed tomography scans using established analytic morphomic techniques. We then determined early recovery among patients with high and low psoas muscle area using the validated Convalescence and Recovery Evaluation (CARE) questionnaire-a 27-item survey, divided into four domains (activity, cognitive, gastrointestinal, and pain recovery). Finally, we assessed the relationship between psoas muscle area and changes in CARE scores with nested linear regression models.

RESULTS

Among the 86 men and among 31 women in our cohort, the median total psoas muscle area was 2,544 mm² and 1,511 mm², respectively (P < 0.001 for the comparison). While there was no association between psoas muscle area and recovery in men, women with higher (versus lower) total psoas muscle area had smaller decreases in their pain scores postoperatively and a quicker return to their baseline level (P = 0.05). Activity scores also approached baseline levels faster among women with higher psoas muscle area, although this finding did not reach statistical significance.

CONCLUSIONS

Psoas muscle area is potentially an important preoperative predictor of recovery for women undergoingradical cystectomy. More broadly speaking, Analytic Morphomics® may represent a novel approach to better understand perioperative risk.

Early development of the mouse morphome

Hampel, J.A., Rinkinen, J., Peterson, J.R., Agarwal, S., Loder, S., Eboda, O., Enchakalody, B., Wang, S.C., Buchman, S.R., Levi, B.

Journal of Craniofacial Surgery, 2016 Apr 19. doi: 10.1097/SCS.0000000000002574.

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INTRODUCTION

Analytical morphomics focuses on extracting objective and quantifiable data from clinical computered tomography (CT) scans to measure patients' frailty. Studies are currently retrospective in nature; therefore, it would be beneficial to develop animal models for well-controlled, prospective studies. The aim of this study is to develop an in vivo microCT protocaol for the longitudinal acquisition of whole-body images suitable for morphomic analyses of bone.

METHODS

The authors performed phantom studies on 2 microCT systems (Inveon and CT120) to study tissue radiodensity and further characterize system performance for collecting animal data. The authors also describe their design of a phantom-immobilization device using phantoms and an ovariectomized (OVX) mouse.

RESULTS

The authors discovered increased consistency along the z-axis for scans acquired on the Inveon compared with CT120, and calibration by individual slice reduces variability. Objects in the field of view had more impact on measurement acquired using the CT120 compared with the Inveon. The authors also found that using the middle 80% of slices for data analysis further decreased variability, on both systems. Moreover, bone-mineral-density calibration using the QCT Pro Mini phantom improved bone-mineral-density estimates across energy spectra, which helped confirm our technique. Comparison of weekly body weights and terminal uterine mass between sham and OVX groups validated our model.

DISCUSSION

The authors present a refined microCT protocol to collect reliable and objective data. This data will be used to establish a platform for research animal morphomics that can be used to test hypotheses developed from clinical human morphomics.

Investigating the clinical significance of body composition changes in patients undergoing chemoradiation for oropharyngeal cancer using Analytic Morphomics®

Wang C, Vainshtein JM, Veksler M, Rabban PE, Sullivan JA, Wang SC, Eisbruch A, Jolly S.

Springerplus. 2016 Apr 11;5:429. doi: 10.1186/s40064-016-2076-x. eCollection 2016.

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BACKGROUND

The purpose is to investigate the clinical significance of body morphomics changes in stage III-IV oropharyngeal cancer patients during concurrent chemoradiotherapy (CRT).

METHODS

Fifty patients who underwent CRT were selected for body composition analyses by either availability of pre/post treatment DEXA scans or a novel CT-based approach of body morphomics analysis (BMA). BMA changes (lean psoas and total psoas area) were compared to total lean body mass changes by DEXA scans using two-sample t tests. Pearson correlation was used to compare the BMA measures to head and neck specific quality of life outcomes. Cox hazards model was used to predict mortality and tumor recurrence.

RESULTS

Clinically significant declines in total psoas area and lean body mass of similar magnitude were observed in both BMA and DEXA cohorts after CRT. Loss of psoas area (P < 0.05) was associated with greater frailty and mobility issues (3 out of 15 UWQ)L domains). Total psoas area is more sensitive for local recurrence than weight changes and T-stage on multivariate analyses.

CONCLUSIONS

BMA specifically evaluating psoas area appears to correlate with head and neck cancer quality of life physical domains. Pre- and post-treatment total psoas area at L4 appears prognostic for tumor recurrence.

Factors Influencing Specificity and Sensitivity of Injury Severity Prediction (ISP) Algorithm for AACN

Pal C, Okabe T, Kulothungan V, Sangolla N, Manoharan J, Wang SC, Combest J.

International Journal of Automotive Engineering. Vol. 7 (2016 Mar 25) No. 1 p. 15-22

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Abstract

To improve the accuracy of Injury Severity Prediction in the event of vehicle crash, a new methodology is proposed using the US vehicle accident database (NASS-CDS). This proposed method is an extension of the base algorithm introduced by Kononen et al. in which, some of the additional variables were introduced and branched logistic regression methodology was used. Results suggest that the proposed branching method has some advantage over the base algorithm due to better linearization of the complex multidimensional non-linear relationship of the input and output variables.

Psoas muscle size as a frailty measure for open and transcatheter aortic valve replacement

Paknikar R, Friedman J, Cron D, Deeb GM, Chetcuti S, Grossman PM, Wang S, Englesbe M, Patel HJ

J Thorac Cardiovasc Surg. 2016 Mar;151(3):745-50. doi: 10.1016/j.jtcvs.2015.11.022. Epub 2015 Nov 21

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OBJECTIVE

To evaluate the use of sarcopenia as a frailty assessment tool for patients with aortic stenosis undergoing surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR).

METHODS

The study cohort comprised 295 patients who underwent either SAVR (n = 156) or TAVR (n = 139). The mean preoperative Society of Thoracic Surgeons mortality risk score was 4.7%. Preoperative computed tomography (CT) scans were used to calculate gender-standardized total psoas area (TPA), as a validated measure of sarcopenia.

RESULTS

For the entire cohort, independent predictors of a composite measure of 30-day death, stroke, renal failure, prolonged ventilation, and deep wound infection included preoperative STS major morbidity and mortality risk score (odds ratio [OR], 91.1; P = .02) and TPA (OR, 0.5; P = .024). Two-year survival was 85.7% in patients with sarcopenia, compared with 93.8% in patients without sarcopenia (P = .02). Independent predictors of late survival included TPA (hazard ratio, 0.47; P = .02). Male sex (OR, 0.52; P = .04) and TPA (OR, 0.6; P = .001) were predictive of high resource utilization. A separate analysis by treatment group found that TPA predicted high resource utilization after SAVR (OR, 0.4; P < .001), but not after TAVR (P = .66).

CONCLUSIONS

CT scan-derived measurement of TPA as an objective frailty assessment tool predicts early morbidity and mortality, high resource utilization, and late survival after treatment for aortic stenosis. The correlation observed between sarcopenia and resource utilization after SAVR versus TAVR suggests that this simple and reproducible risk assessment tool also may help identify those patients who will derive optimal benefit from catheter-based therapy.

Analytic Morphomics®: a novel CT imaging approach to quantify adipose tissue and muscle composition in allogeneic hematopoietic cell translation

Chughtai K, Song Y, Zhang P, Derstine B, Gatza E, Friedman J, Hully L, Inglis C, Goldstein S, Magenau J, Pawarode A, Reddy P, Riwes M, Yank G, Wang SC, Choi SW

Bone Marrow Transplant. 2016 Mar;51(3):446-50. doi: 10.1038/bmt.2015.267. Epub 2015 Nov 9.

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Abdominal Adiposity, body composition and survival after liver transplantation

Terjimanian MN, Harbaugh CM, Hussain A, Olugbade KO Jr, Waits SA, Wang SC, Sonnenday CJ, Englesbe MJ

Clin Transplant. 2016 Mar;30(3):289-94. doi: 10.1111/ctr.12688. Epub 2016 Feb 13.

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BACKGROUND

Current measures of obesity do not accurately describe body composition. Using cross-sectional imaging, objective measures of musculature and adiposity are possible and may inform efforts to optimize liver transplantation outcomes.

METHODS

Abdominal visceral fat area and psoas muscle cross-sectional area were measured on CT scans for 348 liver transplant recipients. After controlling for donor and recipient characteristics, survival analysis was performed using Cox regression.

RESULTS

Visceral fat area was significantly associated with post-transplant mortality (p < 0.001; HR = 0.91 per cm(2), 95% CI: 0.88-0.94). Among patients with smaller TPA, the patients with high visceral fat area had 71.8% one-yr survival compared to 81.8% for those with low visceral fat area (p = 0.15). At five yr, the smaller muscle patients with high visceral fat area had 36.9% survival compared to 58.2% for those with low visceral fat area (p = 0.023).

CONCLUSIONS

Abdominal adiposity is associated with surival after liver transplantation, especially in patients with small trunk muscle size. When coupled with trunk musculature, abdominal adiposity offers direct characterization of body composition that can aid preoperative risk evaluation and inform transplant decision-making.

Limitations of the barcelona clinic liver cancer staging system with a focus on transarterial chemoembolization as a key modality of treatment of hepatocellular carcinoma

Barman PM, Su GL.

Clinical Liver Disease. 2016 February; 7(2):32-35.

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Abstract

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is one of the leading causes of cancer-related death in the United States. Prognosis of HCC remains poor, driven by advanced tumor burden at diagnosis in two-thirds of cases.

Cancer staging systems are important for prognostication and determination of therapy. HCC has unique characteristics for which it is more difficult to use standard cancer staging strategies. First, there is enormous heterogeneity with regard to patient characteristics and HCC biology. Second, in the Western world, the majority of HCC occurs in patients with significant underlying liver disease, making liver function and functional status important in determining outcome. Lastly, tissue diagnosis is not often required, and radiological diagnosis is often the standard. Various staging systems (Table 1) have been proposed to incorporate these variables, but there is no universal worldwide consensus. Two of these staging systems [Barcelona Clinic Liver Cancer (BCLC) and Groupe d'ETUDE et de Traitement du Carcinome Hepatocellulaire (GRETCH)] include performance status, with the BCLC being validated in various geographical settings and with very large data sets. As a result, the BCLC staging system is the most accepted system in the United States, having received the endorsement of both the American Association for the Study of Liver Diseases and the European Association for the Study of Liver Diseases and the European Association for the Study of Liver diseases (Figure 1). Its main advantage is the unique way in which it provides therapy guidelines based on staging, making it a very useful clinical tool.

5^th International ACC Symposium: Surgical Considerations in the Treatment of Adrenocortical Carcinoma: 5^th International ACC Symposium Session: Who, When and What Combination?

Miller, BS.

Horm Cancer. 2016 Feb;7(1):24-8. doi: 10.1007/s12672-0150243-0. Epub 2016 Jan 4.

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Abstract

Significant progress has been made in the understanding of how surgical technique impacts outcome in patients with adrenal cancer. Current and future areas of investigation center on expanding the role of surgery in patients with locally recurrent or metastatic disease, use of neoadjuvant therapy as a bridge to surgery, the impact of formal lymphadenectomy on survival, and improved diagnosis, prognosis, and selection of patients for surgery and other treatments using morphomic analysis.

2015

Sarcopenia and failure to rescue following liver transplantation

Underwood PW, Cron DC, Terjimanian MN, Wang SC, Englesbe MJ, Waits SA

Clin Transplant. 2015 Dec;29(12):1076-80. doi: 10.1111/ctr.12629. Epub 2015 Oct 15.

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INTRODUCTION

Tannenbaum EP, Zhang P, Maratt JD, Gombera MM, Holcombe SA, Wang SC, Bedi A, Goulet JA.

Arthroscopy. 2015 Jul;31(7):1247-54. doi: 10.1016/j.arthro.2015.02.007. Epub 2015 May 13.

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PURPOSE

To assess the prevalence of acetabular retroversion in a large population of patients with asymptomatic hips. Furthermore, we sought to identify gender differences in acetabular morphology to address the current thinking that retroversion and pincer-type femoroacetabular impingement (FAI) are more common in women.

METHODS

We retrospectively reviewed morphologic features of acetabula from a consecutive series of trauma-protocol computed tomography scans of patients without pelvis injury. An automated algorithm determined the acetabular rim profile and center of the femoral head, normalized the frontal plane of the pelvis, and calculated version and coverage. We then compared male and female rim profiles, specifically focusing on version and acetabular wall coverage in the 1-o'clock (anterosuperior), 2-o'clock (central), and 3-o'clock (inferior) positions.

RESULTS

Vaughn V, Cron DC, Terjimanian MN, Gala ZS, Wang SC, Su GL, Volk ML

Clin Transplant. 2015 May;29(5):458-64. doi: 10.1111/ctr.12537. Epub 2015 Apr 16.

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Among liver transplant recipients, development of post-transplant complications such as new-onset diabetes after transplantation (NODAT) is common and highly morbid. Current methods of predicting patient risk are inaccurate in the pre-transplant period, making implementation of targeted therapies difficult. We sought to determine whether Analytic Morphomics® (using computed tomography scans) could be used to predict the incidence of NODAT. We analyzed peri-transplant scans from 216 patients with varying indications for liver transplantation, among whom 61 (28%) developed NODAT. Combinations of visceral fat, subcutaneous fat, and psoas area were considered in addition to traditional risk factors. On multivariate analysis adjusting for usual risk factors such as type of immunosuppression, subcutaneous fat thickness remained significantly associated with NODAT (OR = 1.43, 95% CI 1.00-1.88, p = 0.047). Subgroup analysis showed that patients with later-onset of NODAT had higher visceral fat, whereas subcutaneous fat thickness was more correlated with earlier-onset of NODAT (using 10 months post-transplant as the cut-off).

CONCLUSION

Analytic Morphomics® may be used to help assess NODAT risk in patients undergoing liver transplantation.

Implications of sarcopenia in major surgery

Friedman J, Lussiez A, Sullivan J, Wang S, Englesbe M.

Nutr Clin Pract. 2015 Apr;30(2):175-9. doi: 10.1177/0884533615569888. Epub 2015 Feb 13.

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BACKGROUND

Sarcopenia, defined as a decrease in skeletal muscle mass and strength, is an important risk factor in clinical medicine associated with frailty, mortality, and worse surgical and nonsurgical outcomes. Conventional measures of sarcopenia rely on the subjective "eyeball test" and do not adequately describe risk. Computed tomography (CT) imaging studies may be used to objectively measure sarcopenia and may be used for surgical risk stratification and identification of patients for inclusion in a novel clinical remediation program.

METHODS

We describe results observed in the general, vascular, and liver transplant surgery populations determined by Analytic Morphomics®--an analysis of CT scans in a semiautomated process using MATLAB v13.0. A perioperative optimization program has been implemented with the objective of remediating sarcopenia through improvement of patient mental and physical status prior to surgery.

RESULTS

Using Analytic Morphomics®, we have noted significantly higher cost and increased rates of mortality and surgical complications among sarcopenic patients. The training program shows initial success, and among participating patients, we have observed reductions in payer and hospital costs and a decrease in length of hospital stay for patients following surgery.

CONCLUSIONS

Through Analytic Morphomics®, we are able to quantify markers of sarcopenia and identify patients at risk for increased mortality and poor surgical outcomes. Early identification of patients offers us the opportunity to remediate sarcopenia through perioperative training and support. Participating patients spend less time in the hospital and have lower healthcare costs. This program has the potential to improve the perioperative patient experience and ease financial burdens.

Morphomic analysis as an aid for preoperative risk stratification in patients undergoing major head and neck cancer surgery

Rinkinen J, Agarwal S, Beauregard J, Aliu O, Benedict M, Buchman SR, Wang SC, Levi B

J Surg Res. 2015 Mar;194(1):177-84. doi: 10.1016/j.jss.2014.10.002. Epub 2014 Oct 7.

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BACKGROUND

Patients undergoing major head and neck cancer surgery (MHNCS) may develop significant postoperative complications. To minimize the risk of complications, clinicians often assess multiple measures of preoperative health in terms of medical comorbidities. One emerging method to decrease surgical complications is preoperative assessment of patient frailty measured by specific tissue characteristics. We hypothesize that morphomic characteristics of the temporalis region serve as predictive markers for the development of complications after MHNCS.

METHODS

We performed a retrospective review of 69 patients with available computed tomography (CT) imaging who underwent MHNCS from 2006-2012. To measure temporalis region characteristics, we used morphomic analysis of available preoperative CT scans to map out the region. All available CT scans had been performed as part of the patient's routine work-up and were not ordered for morphomic analysis. We describe the correlation among temporalis fat pad volume (TFPV), mean zygomatic arch thickness, and incidence of postoperative complications.

RESULTS

We noted significant difference in the zygomatic bone thickness and TFPV between patients who had medical complications, surgical complications, or total major complications and those who did not. Furthermore, by use of binary logistic regression, our data suggest decreased TFPV and zygomatic arch thickness are stronger predictors of developing postoperative complications than previously studies preoperative characteristics.

CONCLUSIONS

We describe morphomic analysis of the temporalis region in patients undergoing MHNCS to identify patients at risk for complications. Regional anatomic morphology may serve as a marker to objectively determine a patient's overall health. Use of the temporalis region is appropriate in patients undergoing MHNCS because of the availability of preoperative scans as part of routine work up for head and/or neck cancer.

Visceral adiposity is negatively associated with bone density and muscle attenuation

Zhang P, Peterson M, Su GL, Wang SC

Am J Clin Nutr. 2015 Feb;101(2):337-43. doi: 10.3945/ajcn.113.081778. Epub 2014 Nov 26.

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BACKGROUND

The storage of adipose tissue in ectopic compartments is a hallmark attribute linking greater body mass index (BMI) with cardiometabolic diseases. Despite ample evidence to confirm that increased visceral adipose tissue (VAT) deposition occurs with obesity, the interrelations between altered fat partitioning and regional muscle and bone quality are less well understood.

OBJECTIVE

We examined the association between adiposity and spinal muscle and bone quality across a large, heterogeneous cohort of adults.

DESIGN

We identified 8833 thoracic or abdominal computed tomography scans from patients in the University of Michigan Health System who were aged 18-64.9 y. We measured trabecular bone densities, cortical bone densities, VAT areas, and subcutaneous adipose tissue (SAT) areas at vertebral levels T7 to L5. Psoas muscle attenuation (an indicator of fat infiltration in muscle) was measured at the L4 level.

RESULTS

Muscle attenuation as well as trabecular and cortical bone densities revealed negative correlations with BMI, SAT, and VAT. The correlation between BMI and psoas attenuation was -0.321, between BMI and the density of cortical bone was -0.250, and between BMI and trabecular bone was -0.143 (all P < 0.001). However, correlations between VAT and lower muscle attenuation were stronger as were those between VAT and lower bone densities. Inverse correlations between VAT and densities of psoas muscle and cortical and trabecular bone were -0.460, -0.407, and -0.434, respectively (P < 0.001). Even after adjustment for age, sex, and BMI, partial correlations between VAT, muscle attenuation, and bone densities remained significant at -0.250, -0.119, and -0.216, respectively (P < 0.001).

CONCLUSIONS

Contrary to previous reports that high body mass is associated with increased bone quality, our data show a significant negative association between BMI and muscle and bone densities, suggesting fat infiltration into these tissues. More importantly, correlations between VAT and decreased bone and muscle densities remained statistically significant even after adjustment for age, sex, and BMI.

Use of Analytic Morphomics® of liver, spleen, and body composition to identify patients at risk for cirrhosis

Krishnamurty V, Zhang P, Ethiraj S, Enchakalody B, Waljee AK, Wang L, Wang SC, Su GL

Clin Gastroenterol Hepatol. 2015 Feb;13(2)360-368.e5. doi: 10.1016/j.cgh.2014.07.042. Epub 2014 Jul 30.

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BACKGROUND & AIMS

A diagnosis of cirrhosis can be made on the basis of findings from imaging studies, but these are subjective. Analytic Morphomics® uses computational image processing algorithms to provide precise and detailed measurements of organs and body tissues. We investigated whether morphomic parameters can be used to identify patients with cirrhosis.

METHODS

E. T. Chang, A. Lussiez, J. Li, N. Wang, S. C. Wang

Academic Surgical Congress Abstracts. 2015.

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Introduction

Acute kidney injury (AKI) occurs in approximately 20% of hospitalized adults and costs the US $10 billion annually. Prolonged hospital stay, cost, and mortality have been shown to be increased in these patients and those requiring renal replacement therapy have an even higher mortality rate. In the setting of colon surgery, a recent large scale study found several associated factors with postoperative AKI including advanced age, chronic renal failure, and total colectomy. However, a surgical decision informed by standard clinical data alone may not be sufficient. We set out to study the relationship between AKI and quantitative kidney morphomic factors from cross-sectional preoperative imaging for patients undergoing colectomies and comparing the results with demographic and intra-operative data. We hypothesized that individualized kidney characteristics would correlate with the risk of postoperative AKI development.

Methods

A retrospective review of prospectively gathered data from adult patients undergoing colectomies from 2006-2012 at the University of Michigan was conducted. 390 initial subjects without elevated baseline creatinine values, ESRD, a prior nephrectomy, or renal injury were included. Polycystic kidneys or other kidney abnormalities identified on imaging were excluded resulting in 326 subjects. AKI was defined by the KDIGO criteria within 30 days of injury. Demographic and intraoperative factors were evaluated along with measurements of pertinent kidney morphomic data including volume, surface area, and average Hounsfield Units (HU) which were subjected to univariate analyses.

Results

Of the 326 patients, 60 developed AKI (18.4%). Of demographic factors, advanced age (p=0.0002) and a higher BMI (p=0.02) were associated with AKI. Comorbidities associated with AKI included hypertension (p=0.008) and diabetes (p=0.013). Interestingly, intraoperative factors including surgical time (p=0.13), blood transfusions (p=0.14), blood loss (p=0.42), and hypotensive episodes (p=0.17) were not significantly associated with AKI. Table 1 shows the results of the univariate analysis of the morphomic factors.

Conclusion

AKI is a serious complication and the prevalence after colorectal surgery at our institution was 18.4%. Our analysis shows that a lower average parenchymal HU was the most significant morphomic factor associated with postoperative AKI. This study is the first to provide information that morphomic analysis can be useful in clinical practice to determine which patients are at risk for developing AKI after a colectomy.

2014

Cross-sectional area of the abdomen predicts complication incidence in patients undergoing sternal reconstruction

Kozlow JH, Lisiecki J, Terjimanian MN, Rinkinen J, Brownley RC, Agarwal S, Wang SC, Levi B

J Surg Res. 2014 Dec;192(2):670-7. doi: 10.1016/j.jss.2014.05.041. Epub 2014 May 24

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BACKGROUND

Sternal reconstruction with vascularized flaps is central to the management of sternal wound infections and mediastinitis but carries a high risk of complications. There is a need to identify reliable predictors of complication risk to help inform patients and clinicians in preparation for surgery. Unfortunately, body mass index and serum albumin may not be reliable predictors of complication rates. Analytic Morphomics® provides a robust quantitative method to measure patients' obesity as it pertains to their risk of complications in undergoing sternal reconstruction.

METHODS

We identified 34 patients with preoperative computed tomography scans of the abdomen from a cohort of sternal reconstructions performed between 1997 and 2010. Using semiautomated Analytic Morphomics®, we identified the patients' skin and fascia layers between the ninth and 12th thoracic spine levels; from these landmarks, we calculated morphomic measurements of the patients' abdomens, including their total body cross sectional area and the cross sectional area of their subcutaneous fat. We obtained the incidence of complications from chart review and correlated the incidence of complications (including seroma, hematoma, recurrent wounds, mediastinitis, tracheostomy, and death) with patients' morphomic measurements.

RESULTS

Sixty-two percent of patients (n = 21) suffered complications after their operation. Those who suffered from complications, relative to those who did not have complications, had increased visceral fat area (12,547.2 mm(2)versus 6569.9 mm(2), P = 0.0080), subcutaneous fat area (16,520.2 mm(2)versus 8020.1 mm(2), P = 0.0036), total body area (91,028.6 mm(2)versus 67,506.5 mm(2), P = 0.0022), fascia area (69,238.4 mm(2)versus 56,730.9 mm(2), P = 0.0118), total body circumference (1101.8 mm versus 950.2 mm, P = 0.0017), and fascia circumference (967.5 mm versus 868.1 mm, P = 0.0077). We also demonstrated a significant positive correlation between the previously mentioned morphomic measurements and the incidence of complications in multivariate logistic regression models, with odds ratios ranging from 1.19-3.10 (P values ranging from 0.010-0.022).

CONCLUSIONS

Increases in abdominal morphomic measurements correlate strongly with the incidence of complications in patients undergoing sternal reconstruction. This finding may influence preoperative risk stratification and surgical decision making in this patient population.

Morphomic analysis for preoperative donor site risk assessment in patients undergoing abdominal perforator flap breast reconstruction: a proof of concept study

Levi B, Rinkinen J, Kidwell KM, Benedict M, Stein IC, Lisiecki J, Enchakalody B, Wang SC, Kozlow JH, Momoh AO

J Reconstr Microsurg. 2014 Nov;30(9):635-40. doi: 10.1055/s-0034-1376400. Epub 2014 Jun 9

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BACKGROUND

Morphomics are three-dimensional measurements of aspects of the human anatomy generated by computed tomographic (CT) imaging. The purpose of this study was to generate preliminary data on the efficacy of morphomics, as a potential risk stratification tool, in predicting abdominal donor site wound-healing complications in patients undergoing abdominal perforator flap breast reconstruction.

PATIENTS & METHODS

In total, 58 consecutive patients undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction were evaluated. Using preoperative CT scan data, we quantified patients' body area, visceral and subcutaneous fat, fascia area, and body depth between T12 and L4. Associations between morphomic measures and complication rates were examined using t-tests and logistic regression.

RESULTS

Of the 58 patients, 11 (19%) patients developed a wound dehiscence and 47 (81%) patients healed their abdominal incision without complications. Patients with a dehiscence had a significantly higher body mass index (BMI) (34.32 vs. 29.26 kg/m², p = 0.014) than patients without a dehiscence. Multiple morphometric measures including higher visceral fat area (p = 0.003) were significant predictors of abdominal donor site wound dehiscence. BMI (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.03–1.32; p = 0.017) and visceral fat area (OR, 1.24; 95% CI, 1.08–1.42; p = 0.002) were independently significant predictors for wound dehiscence in the entire sample. Only visceral fat area retained its predictive ability in patients with a BMI > 30 kg/m².

CONCLUSIONS

Morphomic measurements correlate with the likelihood of developing postoperative donor site dehiscence after DIEP flap breast reconstruction. As a proof of concept study, this demonstrates that objective data obtained from CT scans may help in preoperatively assessing the risk for donor site wound healing complications in patients undergoing DIEP flap breast reconstruction.

Analytic Morphomics® corresponds to functional status in older patients

Miller AL, Min LC, Diehl KM, Cron DC, Chan CL, Sheetz KH, Terjimanian MN, Sullivan JA, Palazzolo WC, Wang SC, Hall KE, Englesbe MJ

J Surg Res. 2014 Nov;192(1):19-26. doi: 10.1016/j.jss.2014.06.011. Epub 2014 Jun 11

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BACKGROUND

Older patients account for nearly half of the United States surgical volume, and age alone is insufficient to predict surgical fitness. Various metrics exist for risk stratification, but little work has been done to describe the association between measures. We aimed to determine whether Analytic Morphomics®, a novel objective risk assessment tool, correlates with functional measures currently recommended in the preoperative evaluation of older patients.

MATERIALS & METHODS

We retrospectively identified 184 elective general surgery patients aged >70 y with both a preoperative computed tomography scan and Vulnerable Elderly Surgical Pathways and outcomes Assessment within 90 d of surgery. We used Analytic Morphomics® to calculate trunk muscle size (or total psoas area [TPA]) and univariate logistic regression to assess the relationship between TPA and domains of geriatric function mobility, basic and instrumental activities of daily living (ADLs), and cognitive ability.

RESULTS

Greater TPA was inversely correlated with impaired mobility (odds ratio [OR] = 0.46, 95% confidence interval [CI] 0.25-0.85, P = 0.013). Greater TPA was associated with decreased odds of deficit in any basic ADLs (OR = 0.36 per standard deviation unit increase in TPA, 95% CI 0.15-0.87, P < 0.03) and any instrumental ADLs (OR = 0.53, 95% CI 0.34-0.81; P < 0.005). Finally, patients with larger TPA were less likely to have cognitive difficulty assessed by Mini-Cog scale (OR = 0.55, 95% CI 0.35-0.86, P <0.01). Controlling for age did not change results.

CONCLUSIONS

Older surgical candidates with greater trunk muscle size, or greater TPA, are less likely to have physical impairment, cognitive difficulty, or decreased ability to perform daily self-care. Further research linking these assessments to clinical outcomes is needed.

Paraspinous muscle as a predictor of surgical outcome

Canvasser LD, Mazurek AA, Cron DC, Terjimanian MN, Chang ET, Lee CS, Alameddine MB, Claflin J, Davis ED, Schumacher TM, Wang SC, Englesbe MJ

J Surg Res. 2014 Nov;192(1):76-81. doi: 10.1016/j.jss.2014.05.057. Epub 2014 May 27.

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BACKGROUND

Objective measures for preoperative risk assessment are needed to inform surgical risk stratification. Previous studies using preoperative imaging have shown that the psoas muscle is a significant predictor of postoperative outcomes. Because psoas measurements are not always available, additional trunk muscles should be identified as alternative measures of risk assessment. Our research assessed the relationship between paraspinous muscle area, psoas muscle area, and surgical outcomes.

METHODS

Using the Michigan Surgical Quality Collaborative database, we retrospectively identified 1309 surgical patients who had preoperative abdominal computerized tomography scans within 90 d of operation. Analytic morphomic techniques were used to measure the cross-sectional area of the paraspinous muscle at the T12 vertebral level. The primary outcome was 1-y mortality. Analyses were stratified by sex, and logistic regression was used to assess the relationship between muscle area and postoperative outcome.

RESULTS

The measurements of paraspinous muscle area at T12 were normally distributed. There was a strong correlation between paraspinous muscle area at T12 and total psoas area at L4 (r = 0.72, P <0.001). Paraspinous area was significantly associated with 1-y mortality in both females (odds ratio = 0.70 per standard deviation increase in paraspinous area, 95% confidence interval 0.50-0.99, P = 0.046) and males (odds ratio = 0.64, 95% confidence interval 0.47-0.88, P = 0.006).

CONCLUSIONS

Paraspinous muscle area correlates with psoas muscle area, and larger paraspinous muscle area is associated with lower mortality rates after surgery. This suggests that the paraspinous muscle may be an alternative to the psoas muscle in the context of objective measures of risk stratification.

Dorsal muscle group area and surgical outcomes in liver transplantation

Lee CS, Cron DC, Terjimanian MN, Canvasser LD, Mazurek AA, Vonfoerster E, Tishberg LM, Underwood PW, Chang ET, Wang SC, Sonnenday CJ, Englesbe MJ

Clin Transplant. 2014 Oct;28(10):1092-8. doi: 10.1111/ctr.12422. Epub 2014 Aug 11.

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INTRODUCTION

Better measures of liver transplant risk stratification are needed. Our previous work noted a strong relationship between psoas muscle area and survival following liver transplantation. The dorsal muscle group is easier to measure, but it is unclear if they are also correlated with surgical outcomes.

METHODS

The authors identified 93 patients who underwent component release ventral hernia repair (2004 to 2012). The surgical technique involved release of the external oblique muscle lateral to the linea semilunaris. Using analytic morphomic techniques, the authors measured patients' morphology using routine preoperative computed tomography scans. Two-sample t test was used to evaluate the effect of morphomic and demographic factors on surgical-site infection. Separate logistic regression analyses were performed on these morphomic factors to evaluate their predictive value in assessing the risk of surgical site infection, controlling for demographic covariates.

RESULTS

Surgical site infections were observed in 31 percent (n = 29) of the population. Subcutaneous fat area, total body area, and total body circumference had increased odds ratios for surgical site infection (p = 0.004, 0.014, and 0.012, respectively), indicating that these measures are better associated with surgical site infection than body mass index. These calculations control for demographic covariates, confirming that these morphomic parameters are predictive of surgical site infection.

CONCLUSION

Specific morphomic values serve as superior predictors of surgical site infection in patients undergoing component separation technique hernia repair than currently used values such as body mass index.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Morphometric age and mortality after liver transplant

Waits SA, Kim EK, Terjimanian MN, Tishberg LM, Harbaugh CM, Sheetz KH, Sonnenday CJ, Sullivan JA, Wang SC, Englesbe MJ

JAMA Surg. 2014 Apr;149(4):335-40. doi: 10.1001/jamasurg.2013.4823.

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IMPORTANCE

Morphometric assessment has emerged as a strong predictor of postoperative morbidity and mortality. However, a gap exists in translating this knowledge to bedside decision making. We introduced a novel measure of patient-centered surgical risk assessment: morphometric age.

OBJECTIVE

To investigate the relationship between morphometric age and posttransplant survival.

DATA SOURCES

Medical records of recipients of deceased-donor liver transplants (study population) and kidney donors/trauma patients (morphometric age control population).

STUDY SELECTION

A retrospective cohort study of 348 liver transplant patients and 3313 control patients. We assessed medical records for validated morphometric characteristics of aging (psoas area, psoas density, and abdominal aortic calcification). We created a model (stratified by sex) for a morphometric age equation, which we then calculated for the control population using multivariate linear regression modeling (covariates). These models were then applied to the study population to determine each patient's morphometric age.

DATA EXTRACTION AND SYNTHESIS

All analytic steps related to measuring morphometric characteristics were obtained via custom algorithms programmed into commercially available software. An independent observer confirmed all algorithm outputs. Trained assistants performed medical record review to obtain patient characteristics.

RESULTS

Cox proportional hazards regression model showed that morphometric age was a significant independent predictor of overall mortality (hazard ratio, 1.03 per morphometric year [95% CI, 1.02-1.04; P < .001]) after liver transplant. Chronologic age was not a significant covariate for survival (hazard ratio, 1.02 per year [95% CI, 0.99-1.04; P = .21]). Morphometric age stratified patients at high and low risk for mortality. For example, patients in the middle chronologic age tertile who jumped to the oldest morphometric tertile have worse outcomes than those who jumped to the youngest morphometric tertile (74.4% vs 93.2% survival at 1 year [P = .03]; 45.2% vs 75.0% at 5 years [P = .03]).

CONCLUSIONS & RELEVANCE

Morphometric age correlated with mortality after liver transplant with better discrimination than chronologic age. Assigning a morphometric age to potential liver transplant recipients could improve prediction of postoperative mortality risk.

Use of morphomic analysis for preoperative risk stratification in patients undergoing major head and neck cancer surgery

Rinkinen J, Agarwal S, Terjimanian M, Beauregard J, Ranganathan K, Benedict M, Hiltzik D, Stein I, Lisiecki J, Wang SC, Buchman SR, Levi B.

Plast Reconstr Surg. 2014 Mar;133(3 Suppl):131. doi: 10.1097/01.prs.0000444939.16228.9f.

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Temporalis muscle morphomics: the psoas of the craniofacial skeleton

Ranganathan K, Terjimanian M, Lisiecki J, Rinkinen J, Mukkamala A, Brownley C, Buchman SR, Wang SC, Levi B

J Surg Res. 2014 Jan;186(1):246-52. doi: 10.1016/j.jss.2013.07.059. Epub 2013 Aug 30.

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BACKGROUND

The psoas muscle has been shown to predict patient outcomes based on the quantification of muscle area using computed tomography (CT) scans. The accuracy of morphomic analysis on other muscles has not been clearly delineated. In this study, we determine the correlation between temporalis muscle mass, psoas muscle area, age, body mass index (BMI), and gender.

METHODS

Temporalis and psoas muscle dimensions were determined on all trauma patients who had both abdominal and maxillofacial CT scans at the University of Michigan between 2004 and 2011. Age, BMI, and gender were obtained through chart review. Univariate and multivariate analyses were performed to determine the relative relationship between morphomic data of the temporalis and psoas muscles and the ability of such information to correspond with clinical variables, such as BMI, age, and gender.

RESULTS

A total of 646 patients were included in the present study. Among the 249 (38.5%) women and 397 (61.5%) men, the average age was 49.2 y. Average BMI was 27.9 kg/m². Total psoas muscle area directly correlated with mean temporalis muscle thickness (r = 0.57, P < 0.001). There was an indirect correlation between age and psoas muscle area (r = -0.52, P < 0.001) and temporalis muscle thickness (r = -0.36, P < 0.001). Neither psoas nor temporalis measurements correlated strongly with BMI (r = 0.18, P < 0.001; r = 0.14, P = 0.002), although stronger correlations were found in a more "frail," subgroup as defined by a BMI of <20 (r = 0.59, P = 0.002).

CONCLUSIONS

We demonstrate that dimensions of the temporalis muscle can be quantified and may serve as a proxy for age. Going forward, we aim to assess the utility of temporalis and psoas morphomics in predicting complication rates among trauma patients admitted to the hospital to predict outcomes in the future.

Characterization of vertebral angle and torso depth by gender and age groups with a focus on occupant safety

Parenteau CS, Zhang P, Holcombe S, Wang SC

Traffic Inj Prev. 2014;15(1):66-72. doi: 10.1080/15389588.2013.829217.

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OBJECTIVE

The human body changes as it becomes older. The automotive safety community has been interested in understanding the effect of age on restraint performance. Focus has been placed on characterizing the body's structural changes associated with age and gender. In this study, spine alignment and torso depth were assessed, because both variables have been shown to affect injury risk.

METHODS

The data was obtained from computed tomography (CT) scans of more than 24,000 patients aged 16 and older. The data consisted of thoracic and lumbar vertebral angles relative to a fixed plane, as well as vertebra-to-front skin and spine-to-back skin distances. Angle measurements were taken in the sagittal plane at each vertebra level from T1 to L5; distance measurements were taken from T6 to L5. The data were analyzed as a function of gender and age with the young group defined as 16 to 29 years old and the older group as 75 and up.

Rinkinen J, Zhang P, Wang L, Enchakalody B, Terjimanian M, Holcombe S, Wang SC, Buchman SR, Levi B.

J Craniofac Surg. 2013 Jan;24(1):250-5. doi: 10.1097/SCS.0b013e31827006f5.

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INTRODUCTION

Analytical morphomics is the term we created to describe an innovative, highly automated, anatomically indexed processing of 3D medical imaging data captured during the course of a patients' preoperative CT scan. Our specific aim is to determine the efficacy of craniofacial morphomic indices (CMI) such as temporalis muscle and temporal fat pad morphometric values to predict blood transfusion requirement and hospital stay in a cohort of children with nonsyndromic craniosynostosis (NSC).

METHODS

High-throughput, semi-automated image analysis was used to reconstruct the 3-dimensional anatomy of the temporalis muscle and temporal fat pad and to quantify CMIs. The prognostic effect of CMI on clinical outcomes were evaluated among all NSC patients and compared across various craniosynostosis subtypes using Wilcoxon nonparametric tests and Kendall's τ to determine significance.

RESULTS

Using preoperative CT images, we evaluated 117 children with NSC from the University of Michigan Health System. Results demonstrate that increased temporal fat pad volume and local temporalis muscle volume are associated with better clinical outcomes in craniosynostosis patients. More specifically, temporal fat pad volume was shown to be a significant predictor of perioperative blood transfusion requirements (P = 0.0033) and increased temporal muscle volume correlated with decreased hospital stay (P = 0.016) when controlling for other covariates including age, sex, weight, and preoperative hematocrit. In addition, the same significant predictors were found when examining individual subtypes of craniosynostosis.

CONCLUSION

Our findings demonstrate that maxillofacial CT scans provide a useful quantitative index reflecting general patient health, risk stratification, and probabilities of intervention in addition to their previously established ability to determine the specific pathology of the patient. We demonstrate that temporal morphomics predict the incidence of blood transfusion, hospital stay, and serve as a proxy for fitness in patients undergoing craniosynostosis surgery.

2012

Quantifying the eyeball test: sarcopenia, Analytic Morphomics®, and liver transplantation

Englesbe, MJ

Liver Transpl. 2012 Oct;18(10):1136-7. doi: 10.1002/lt.23510.

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Analytic Morphomics®, core muscle size, and surgical outcomes

Englesbe MJ, Lee JS, He K, Fan L, Schaubel DE, Sheetz KH, Harbaugh CM, Holcombe SA, Campbell DA, Sonnenday CJ, Wang SC

Ann Surg. 2012 Aug;256(2):255-61. doi: 10.1097/SLA.0b013e31826028b1.

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OBJECTIVE

Assess the relationship between lean core muscle size, measured on preoperative cross-sectional images, and surgical outcomes.

BACKGROUND

Novel measures of preoperative risk are needed. Analytic morphomic analysis of cross-sectional diagnostic images may elucidate vast amounts of patient-specific data, which are never assessed by clinicians.

METHODS

The study population included all patients within the Michigan Surgical Quality Collaborative database with a computerized tomography(CT) scan before major, elective general or vascular surgery (N = 1453). The lean core muscle size was calculated using analytic morphomic techniques. The primary outcome measure was survival, whereas secondary outcomes included surgical complications and costs. Covariate adjusted outcomes were assessed using Kaplan-Meier analysis, multivariate cox regression, multivariate logistic regression, and generalized estimating equation methods.

RESULTS

The mean follow-up was 2.3 years and 214 patients died during the observation period. The covariate-adjusted hazard ratio for lean core muscle area was 1.45 (P = 0.028), indicating that mortality increased by 45% per 1000 mm(2) decrease in lean core muscle area. When stratified into tertiles of core muscle size, the 1-year survival was 87% versus 95% for the smallest versus largest tertile, whereas the 3-year survival was 75% versus 91%, respectively (P < 0.003 for both comparisons). The estimated average risk of complications significantly differed and was 20.9%, 15.0%, and 12.3% in the lower, middle, and upper tertiles of lean core muscle area, respectively. Covariate-adjusted cost increased significantly by an estimated $10,110 per 1000 mm(2) decrease in core muscle size (P = 0.003).

CONCLUSIONS

Core muscle size is an independent and potentially important preoperative risk factor. The techniques used to assess preoperative CT scans, namely Analytic Morphomics®, may represent a novel approach to better understanding patient risk.

Use of Temporal Morphomic Indices as a Clinically Important Variable in the Diagnosis of Nonsyndromic Craniosynostosis

Rinkinen J, Wang L, Zhang P, Lisiecki J, Enchakalody B, Holcombe S, Dombrowski A, Wang SC, Buchman SR, Levi B

Ann Plast Surg. 2012 Jul 31;73(1):86-91. doi: 10.1097/SAP.0b013e31826caf8d.

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INTRODUCTION

Preoperative computed tomography (CT) evaluation of patients with nonsyndromic craniosynostosis (NSC) has focused on the bony cranial vault while ignoring the surrounding soft tissues. In this study, we posit that novel CT-derived temporal muscle and temporal fat pad morphomics (tissue thickness, area, and volume) can be used to calculate temporal morphomic indices (TMIs), which are unique to each NSC subtype (metopic, coronal, and sagittal) and divergent from normal individuals.

METHODS

High-throughput image analysis was used to reconstruct the 3-dimensional anatomy and quantify a TMI. These steps were completed in a semiautomated method using algorithms programmed in MATLAB v13.0. Differences in TMI across various craniosynostosis subtypes were assessed using Wilcoxon nonparametric tests for both patients with NSC and a control cohort of patients with trauma.

RESULTS

Using preoperative CT images, we evaluated 117 children with NSC from the University of Michigan Health System and 50 age-matched control patients between 1999 and 2011. Results indicate significant differences in TMI among the normal and NSC groups, with normal patients having significantly higher TMI values than patients with metopic, sagittal, and coronal synostosis. In addition, significant differences were found to exist between each craniosynostosis category.

CONCLUSIONS

Patients with craniosynostosis demonstrate diminished temporalis muscle and overlying fat pad volume and thickness compared with control patients. The unique changes in temporal morphomics presented in this article demonstrate not only that the bony calvaria is affected by craniosynostosis but also that there exist quantifiable aberrations in the temporalis muscle and temporal fat pad. The methodologies described offer a novel methodology to use pre-existing CT scans to glean additional preoperative information on the soft tissue characteristics of patients with craniosynostosis.

Worsening central sarcopenia and increasing intra-abdominal fat correlate with decreased survival in patients with adrenocortical carcinoma

Miller BS, Ignatoski KM, Daignault S, Lindland C, Doherty M, Gauger PG, Hammer GD, Wang SC, Doherty GM

World J Surg. 2012 Jul;36(7):1509-16. doi: 10.1007/s00268-012-1581-5.

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BACKGROUND

Accurate prediction of survival from adrenocortical carcinoma (ACC) is difficult and current staging models are unreliable. Central sarcopenia as part of the cachexia syndrome is a marker of frailty and predicts mortality. This study seeks to confirm that psoas muscle density (PMD), lean psoas muscle area (LPMA), lumbar skeletal muscle index (LSMI), and intra-abdominal (IA) or subcutaneous fat (SC) can be used in combination to more accurately predict survival in ACC patients.

METHODS

PMD, LPMA, IA, and SC fat were measured on serial CT scans of patients with ACC. Clinical outcome was correlated with quantitative data from patients with ACC and analyzed. A linear regression model was used to describe the relationship between PMD, LPMA, LSMI, IA, and SC fat, time to recurrence, and length of survival according to tumor stage.

RESULTS

One hundred twenty-five ACC patients (94 females) were treated from 2005 to 2011. Significant morphometric predictors of survival include PMD, LPMA, and IA fat (p ≤ 0.0001, ≤ 0.0024, <0.0001, respectively) and improve prediction of survival compared to using stage alone. A 100-mm(2) increase in LPMA confers an 8% lower hazard of death. LSMI does not change significantly between stages (p = 0.3196).

CONCLUSION

Decreased PMD, LPMA, and increased IA fat suggest decreased survival in ACC patients and correlate with traditional staging systems. A more precise prediction of survival may be achieved when staging systems and morphometric measures are used in combination. Serial measurements of morphometric data are possible. The rate of change of these variables over time may be more important than the absolute value.

Morphomic Analysis of Cervical Facet Angles

Wang NC, Holcombe SA, Cohan RD, Kohoyda-Inglis C, Wang, SC

Holcombe S, Kohoyda-Inglis C, Wang L, Goulet JA, Wang SC, Kent RW

Stapp Car Crash J. 2011 Nov;55:479-90.

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Abstract

The size and shape of the acetabulum and of the femoral head influence the injury tolerance of the hip joint. The aim of this study is to quantify changes in acetabular cup geometry that occur with age, gender, height, and weight. Anonymized computed tomography (CT) scans of 1,150 individuals 16+ years of age, both with and without hip trauma, were used to describe the acetabular rim with 100 equally spaced points. Bilateral measurements were taken on uninjured patients, while only the uninjured side was valuated in those with hip trauma. Multinomial logistic regression found that after controlling for age, height, weight, and gender, each 1 degree decrease in acetabular anteversion angle (AAA) corresponded to an 8 percent increase in fracture likelihood (p<0.001). Age, weight, and gender were found to influence anteversion angle significantly, with each 10 years in age increasing AAA by 1.07 degrees, each 10 kg of weight decreasing AAA by 0.45 degrees, and being female resulting in 1.42 degrees greater AAA than males. Height was not found to relate significantly to AAA after other anthropometric factors were controlled for. Height, age, and weight, however, correlated with femoral head radius, thus establishing a relationship with acetabular rim size independent of rim shape. A parametric model of the 3D acetabular rim landmark points is reported, allowing for the creation of individualized acetabular geometry for any given age, gender, height, and weight. A custom-built tool to produce such geometry programmatically is also provided.

Surgical site infection and analytic morphometric assessment of body composition in patients undergoing midline laparotomy

Lee JS, Terjimanian MN, Tishberg LM, Alawieh AZ, Harbaugh CM, Sheetz KH, Holcombe SA, Wang SC, Sonnenday CJ, Englesbe MJ

J Surg Res. 2011 Aug;213(2):236-244. doi: 10.1016/j.jamcollsurg.2011.04.008

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BACKGROUND

Obesity is a known risk factor for surgical site infection (SSI). Our hypothesis is that morphometric measures of midline subcutaneous fat will be associated with increased risk of SSI and will predict SSI better than conventional measures of obesity.

STUDY DESIGN

We identified 655 patients who underwent midline laparotomy (2006 to 2009) using the Michigan Surgical Quality Collaborative database. Using novel, semiautomated analytic morphometric techniques, the thickness of subcutaneous fat along the linea alba was measured between T12 and L4. To adjust for variations in patient size, subcutaneous fat was normalized to the distance between the vertebrae and anterior skin. Logistic regression analyses were used to identify factors independently associated with the incidence of SSI.

RESULTS

Overall, SSIs were observed in 12.5% (n = 82) of the population. Logistic regression revealed that patients with increased subcutaneous fat had significantly greater odds of developing a superficial incisional SSI (odds ratio [OR] = 1.76 per 10% increase, 95% CI 1.10 to 2.83, p = 0.019). Smoking, steroid use, American Society of Anesthesiologists (ASA) classification, and incision-to-close operative time were also significant independent risk factors for superficial incisional SSI. When comparing subcutaneous fat and body mass index (BMI) as the only model variables, subcutaneous fat significantly improved model predictions of superficial incisional SSI (area under the receiver operating characteristic curve [AUC] 0.60, p = 0.023); BMI did not (AUC 0.52, p = 0.73).

CONCLUSIONS

Abdominal subcutaneous fat is an independent predictor of superficial incisional SSI after midline laparotomy. Novel morphometric measures may improve risk stratification and help elucidate the pathophysiology of surgical complications.

Central Adiposity and Surgical Site Infection in Patients Undergoing Midline Laparotomy

Lee JS, Terjimanian MN, Alawieh AZ, Tishberg LM, Harbaugh CM, Kowalsky DB, Sheetz KH, Holcombe Sa, Wang SC, Englesbe MJ

J Surg Res. 2011 Feb;165(2):199-200. doi: 10.1016/j.jss.2010.11.600.

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Abstract

Obesity is a known risk factor for surgical site infection (SSI). Although body mass index (BMI) and body fat percentage are typically used to define obesity, these metrics do not directly assess body composition at the site of the wound. Within this context, measures of adiposity targeted at the surgical site may improve predictions of SSI risk. Such measures can be readily obtained from preoperative cross-sectional imaging. The objective of this study is to determine whether the amount of abdominal fat along the midline is correlated with SSI in patients undergoing procedures requiring midline laparotomy.

Safety Belt & Occupant Factors Influencing Thoracic and Upper Abdominal Injuries in Frontal Crashes

Lu H, Andreen M, Faust D, Furton L, Holcombe S, Kohoyda-Inglis C, Putala B, Yee J, Wang S.

SAE International. 2011; #2011-01-1129.

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Abstract

This paper reports on a study that examines the effect of shoulder belt load limiters and pretensioners as well as crash and occupant factors that influence upper torso harm in real world frontal crashes. Cases from the University of Michigan International Center for Automotive Medicine (ICAM) database were analyzed. Additional information was used from other databases including the National Highway Traffic Safety Administration (NHTSA) New Car Assessment Program (NCAP), the Insurance Institute for Highway Safety (IIHS), the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS), and patient data available from the University of Michigan Trauma Center. The ICAM database is comprised of information from real world crashes in which occupants were seriously injured and required treatment at a Level 1 Trauma Center. Cases from the database were included in this study if they met the following criteria: (a) the primary collision involved a frontal type crash and; (b) case occupants were seated in front outboard positions, restrained by 3-point safety belts and deployed frontal airbags. One hundred thirty three (133) case occupants who sustained nearly 1,800 injuries were selected for study from the ICAM database. The study included evaluations of skeletal, organ, and vessel injuries to the upper torso. Potential influencing factors were divided into three general categories: vehicle factors (i.e. seatbelt design); occupant factors; and crash related factors. Considering the challenges and limitations for analysis of field accident data and within the scope of this study, data indicated that: case occupants without shoulder belt load limiters experienced a higher level of upper torso harm in lower severity frontal crashes. The average Delta V for case occupants with shoulder belt load limiters was significantly higher (7.1 km/h, 34% greater crash energy) than that for the case occupants without load limiters. Case occupants with shoulder belt load limiters had significantly fewer clavicle fractures in frontal crashes. For the 62 case occupants with load limiters, the presence or absence of pretensioners did not appear to substantially change the crash severity associated with AIS ≥2 upper torso harm. Lower bone mineral density of the L4 vertebra was indicative of susceptibility to upper torso skeletal injuries. Smaller psoas muscle cross section area was indicative of susceptibility to upper torso internal and skeletal injuries.

2010

Sarcopenia and mortality after liver transplantation

Englesbe MJ, Patel SP, He K, Lynch RJ, Schaubel DE, Harbaugh C, Holcombe SA, Wang SC, Segev, DL, Sonnenday CJ

J Am Coll Surg. 2010 Jan;211(2):271-278. doi: 10.1016/j.jamcollsurg.2010.03.039

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BACKGROUND

Surgeons frequently struggle to determine patient suitability for liver transplantation. Objective and comprehensive measures of overall burden of disease, such as sarcopenia, could inform clinicians and help avoid futile transplantations.

STUDY DESIGN

The cross-sectional area of the psoas muscle was measured on CT scans of 163 liver transplant recipients. After controlling for donor and recipient characteristics using Cox regression models, we described the relationship between psoas area and post-transplantation mortality.

RESULTS

Psoas area correlated poorly with Model for End-Stage Liver Disease score and serum albumin. Cox regression revealed a strong association between psoas area and post-transplantation mortality (hazard ratio = 3.7/1,000 mm2 decrease in psoas area; p < 0.0001). When stratified into quartiles based on psoas area (holding donor and recipient characteristics constant), 1-year survival ranged from 49.7% for the quartile with the smallest psoas area to 87.0% for the quartile with the largest. Survival at 3 years among these groups was 26.4% and 77.2%, respectively. The impact of psoas area on survival exceeded that of all other covariates in these models.

CONCLUSIONS

Central sarcopenia strongly correlates with mortality after liver transplantation. Such objective measures of patient frailty, such as sarcopenia, can inform clinical decision making and, potentially, allocation policy. Additional work is needed develop valid and clinically relevant measures of sarcopenia and frailty in liver transplantation.

Frailty, core muscle size, and mortality in patients undergoing open abdominal aortic aneurysm repair

Lee JS, He K, Harbaugh CM, Schaubel DE, Sonnenday CJ, Wang SC, Englesbe MJ, Eliason JL

J Vasc Surg. 2010 June 10-13;53(4):912-7. doi: 10.1016/j.jvs.2010.10.111. Epub 2011 Jan 7.

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OBJECTIVES

Determining operative risk in patients undergoing aortic surgery is a difficult process, as multiple variables converge to affect overall mortality. Patient frailty is certainly a contributing factor, but is difficult to measure, with surgeons often relying on subjective or intuitive influences. We sought to use core muscle size as an objective measure of frailty, and determine its utility as a predictor of survival after abdominal aortic aneurysm (AAA) repair.

METHODS

Four hundred seventy-nine patients underwent elective open AAA repair between 2000 and 2008. Two hundred sixty-two patients (54.7%) had preoperative computed tomography (CT) scans available for analysis. Cross-sectional areas of the psoas muscles at the level of the L4 vertebra were measured. The covariate-adjusted effect of psoas area on postoperative mortality was assessed using Cox regression.

RESULTS

Of the 262 patients, there were 55 deaths and the mean length of follow-up was 2.3 years. Cox regression revealed a significant association between psoas area and postoperative mortality (P = .003). The effect of psoas area was found to decrease significantly as follow-up time increased (P = .008). Among all covariates included in the Cox models (including predictors of mortality such as American Society of Anesthesiologists [ASA] score), the psoas area was the most significant.

CONCLUSION

Core muscle size, an objective measure of frailty, correlates strongly with mortality after elective AAA repair. A better understanding of the role of frailty and core muscle size may aid in risk stratification and impact timing of surgical repair, especially in more complex aortic operations.

2009

Analysis of injury trends in frontal University of Michigan CIREN cases in the context of crash tests

O'Brien-Mitchell B, Baily K, Faust D, Jensen J, Kleinert J, Wodzinski C, Kohoyda-Inglis C, Wang SC.

Proceedings of the 21^st International Technical Conference on the Enhanced Safety of Vehicles (ESV), 2009. Technical Paper #09-0188-W.

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Four-hundred forty two U-M CIREN (University of Michigan Crash Injury Research and Engineering Network) cases have previously been compared to crash tests used in the automotive industry. The comparison demonstrated that the majority of cases were similar in crash configuration and extent to industry crash tests, while smaller proportions either had a greater extent of crash deformation or had different crash configurations than those commonly produced in crash tests. Of the 442 cases, 290 frontal cases were analyzed in greater detail to understand trends in injury causation while considering physical characteristics of occupants (gender, age, body mass index.) Those trends were then evaluated in the context of biomechanics of crash test tools such as Anthropomorphic Test Devices [ATDs] and injury risk curves. Several trends were identified and presented.

Ehrlich PF, Brown JK, Sochor MR, Wang SC, Eichelberger ME.

J Pediatr Surg. 2006 Nov;41(11):1854-8.

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BACKGROUND/PURPOSE

Motor vehicle crashes account for more than 50% of pediatric injuries. Triage of pediatric patients to appropriate centers can be based on the crash/injury characteristics. Pediatric motor vehicle crash/injury characteristics can be determined from an in vitro laboratory using child crash dummies. However, to date, no detailed data with respect to outcomes and crash mechanism have been presented with a pediatric in vivo model.

METHODS

The Crash Injury Research Engineering Network is comprised of 10 level 1 trauma centers. Crashes were examined with regard to age, crash severity (DeltaV), crash direction, restraint use, and airbag deployment. Multiple logistic regression analysis was performed with Injury Severity Score (ISS) and Glasgow Coma Scale (GCS) as outcomes. Standard age groupings (0-4, 5-9, 10-14, and 15-18) were used. The database is biases toward a survivor population with few fatalities.

RESULTS

Four hundred sixty-one motor vehicle crashes with 2500 injuries were analyzed (242 boys, 219 girls). Irrespective of age, DeltaV > 30 mph resulted in increased ISS and decreased GCS (eg, for 0-4 years, DeltaV < 30: ISS = 10, GCS = 13.5 vs DeltaV > 30: ISS = 19.5, GCS = 10.6; P < .007, < .002, respectively). Controlling for DeltaV, children in lateral crashes had increased ISS and decreased GCS versus those in frontal crashes. Airbag deployment was protective for children 15 to 18 years old and resulted in a lower ISS and higher GCS (odds ratio, 2.1; 95% confidence interval, 0.9-4.6). Front-seat passengers suffered more severe (ISS > 15) injuries than did backseat passengers (odds ratio, 1.7; 95% confidence interval, 0.7-3.4). A trend was noted for children younger than 12 years sitting in the front seat to have increased ISS and decreased GCS with airbag deployment but was limited by case number.

CONCLUSION

A reproducible pattern of increased ISS and lower GCS characterized by high severity, lateral crashes in children was noted. Further analysis of the specific injuries as a function and the crash characteristic can help guide management and prevention strategies.

Patterns of severe injury in pediatric car crash victims: Crash Injury Research Engineering Network database

Brown JK, Jing Y, Wang S, Ehrlich PF.

J Pediatr Surg. 2006 Feb;41(2):362-7.

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BACKGROUND/PURPOSE

Motor vehicle crashes (MVCs) account for 50% of pediatric trauma. Safety improvements are typically tested with child crash dummies using an in vitro model. The Crash Injury Research Engineering Network (CIREN) provides an in vivo validation process. Previous research suggest that children in lateral crashes or front-seat locations have higher Injury Severity Scale scores and lower Glasgow Coma Scale scores than those in frontal-impact crashes. However, specific injury patterns and crash characteristics have not been characterized.

METHODS

Data were collected from the CIREN multidisciplinary crash reconstruction network (10 pediatric trauma centers). Injuries were examined with regard to crash direction (frontal/lateral), restraint use, seat location, and change in velocity at impact (DeltaV). Injuries were limited to Abbreviated Injury Scale (AIS) scores of 3 or higher and included head, thoracic, abdominal, pelvic, spine, and long bone (orthopedic) injuries. Standard age groupings (0-4, 5-9, 10-14, and 15-18 years) were used. Statistical analyses used Fisher's Exact test and multiple logistic regressions.

RESULTS

Four hundred seventeen MVCs with 2500 injuries were analyzed (males = 219, females = 198). Controlling for DeltaV and age, children in lateral-impact crashes (n = 232) were significantly more likely to suffer severe injuries to the head and thorax as compared with children in frontal crashes (n = 185), who were more likely to suffer severe spine and orthopedic injuries. Children in a front-seat (n = 236) vs those in a back-seat (n = 169) position had more injuries to the thoracic (27% vs 17%), abdominal (21% vs 13%), pelvic (11% vs 1%), and orthopedic (28% vs 10%) regions (P < .05 for all). Seat belts were protective for pelvic (5% vs 12% unbelted) and orthopedic (15% vs 40%) injuries (odds ratio = 3, P < .01 for both).

CONCLUSION

A reproducible pattern of injury is noted for children involved in lateral-impact crashes characterized by head and chest injuries. The Injury Severity Scale scores were higher for children in front-seat positions. Increased lateral-impact safety measures such as mandatory side curtain airbags may decrease morbidity. Furthermore, continued public education for positioning children in the back seat of cars is warranted.

2005

Structural and material changes in the aging thorax and their role in crash protection for older occupants

Kent R, Lee S-H, Darvish K, Poster CD, Lange AW, Brede C, Lange D, Wang SC, Matsuoka F.

Stapp Car Crash J. 2005 Nov;49:231-49.

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Abstract

The human body undergoes a variety of changes as it ages through adulthood. These include both morphological (structural) changes (e.g., increased thoracic kyphosis) and material changes (e.g., osteoporosis). The purpose of this study is to evaluate structural changes that occur in the aging bony thorax and to assess the importance of these changes relative to the well-established material changes. The study involved two primary components. First, full-thorax computed tomography (CT) scans of 161 patients, age 18 to 89 years, were analyzed to quantify the angle of the ribs in the sagittal plane. A significant association between the angle of the ribs and age was identified, with the ribs becoming more perpendicular to the spine as age increased (0.08 degrees/year, p=0.012). Next, a finite element model of the thorax was used to evaluate the importance of this rib angle change relative to other factors associated with aging. A three-factor, two-level factorial design was used to assess the relative importance of rib cage morphology ("young" and "old" rib angle), thickness of the cortical shell (thick = "young" and thin = "old"), and the bone material properties ("young" and "old") on the force-deflection response and injury tolerance of the thorax. The simulations showed that the structural and material changes played approximately equal roles in modulating the force-deflection response of the thorax. Changing the rib angle to be more perpendicular to the spine increased the effective thoracic stiffness, while the "old" material properties and the thin cortical shell decreased the effective stiffness. The offsetting effects of these traits resulted in similar effective thoracic stiffness for the "elderly" and baseline thoracic models, which is consistent with cadaver data available in the literature. All three effects tended to decrease chest deflection tolerance for rib fractures, though the material changes dominated (a four- to six-fold increase in elements eliminated using a maximum strain criterion). The primary conclusion, therefore, is that an older person's thorax, relative to a younger, does not necessarily deform more in response to an applied force. The tolerable sternal deflection level is, however, much less.

2004

Potential applications (and limitations) of 3D imaging data from human crash subjects for biomechanical research

Wang SC, Lange AW, Poster CS, Brede C, Lange D.

Society of Automotive Engineers. 2004. Paper #2004-01-0331.

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Abstract

Most studies investigating the biomechanics of injury are limited by a paucity of data about the physical characteristics of the subject before the injury occurred. This is particularly the case with live human subjects from real-life cases, where little data except age, gender, height and weight have been available to date. With regard to the injuries themselves, previously available data has generally been descriptive and of insufficient granularity and anatomic specificity to provide insight into the path of force loading through the surrounding tissues or the mechanism of injury. Three-dimensional medical imaging has recently become part of the standard evaluation of injured subjects and a growing pool of this data is becoming available to the biomechanical research community. When reviewed in conjunction with detailed crash and vehicle information, this data can provide invaluable information regarding the baseline physical characteristics that may have affected the subject's injury tolerance as well as insight into injury mechanism. Taken out of the proper context or with improper image processing, portions of this imaging data can be misleading. The objective of this study is to review changes in medical imaging technology over the past two decades as well as changes in its utilization for the standard evaluation of injured patients. Analysis of 3D medical imaging data for biomechanical studies requires image data processing beyond that used during interpretation for clinical purposes; these processes will be reviewed so that members of the biomechanical research community can better understand the potential uses and limitations of this data. The argument will be made for the research community to adopt common standards and procedures. Individual case studies will demonstrate the conditions under which pre-injury body composition data can be extracted from post- injury 3D medical imaging data. Pooled data will demonstrate the association that exists between these body composition data and observed injury tolerance. The implications of this data for the design and validation of finite element models capable of accurately predicting body tolerances to injury will be discussed.

Gender Differences in Hip Anatomy: Possible Implications for Injury Tolerance in Frontal Collisions

Wang SC, Brede C, Lange D, Poster CS, Lange AW, Kohoyda-Inglis C, Sochor MR, Ipaktchi K, Rowe SA, Patel S, Garton H.

Annual Proceedings of the Association for the Advancement of Automotive Medicine. 2004; 48:287-301.

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Abstract

Male occupants in frontal motor vehicle collisions have reduced tolerance for hip fractures than females in similar crashes. We studied 92 adult pelvic CT scans and found significant gender differences in bony pelvic geometry, including acetabular socket depth and femoral head width. Significant differences were also noted in the presentation angle of the acetabular socket to frontal loading. The observed differences provide biomechanical insight into why hip injury tolerance may differ with gender. These findings have implications for the future design of vehicle countermeasures as well as finite element models capable of more accurately predicting body tolerances to injury.

2003

The cushion effect

Arbabi S, Wahl W, Hemmila M, Kohoyda-Inglis C, Taheri P, Wang, SC

J Trauma. 2003 Jun;54(6):1090-3.

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BACKGROUND

The pattern and severity of crash injury depends on a complex interaction of biomechanical factors such as deceleration velocity at impact (delta-V), seat-belt and airbag use, and type of impact. Human body characteristics such as height and weight may play an important role. We hypothesized that body mass index (BMI) will influence crash injury patterns.

METHODS

The University of Michigan Program for Injury Research and Education database was queried. Three cohorts were analyzed, lean (BMI </= 25 kg/m2), overweight (BMI 25-30 kg/m2), and obese (BMI > 30 kg/m2)

RESULTS

There were 189 detailed crash cases, with 22 fatalities. There was an increased risk of fatal outcome associated with the obese cohort (adjusted odds ratio, 4.2 compared with lean; p = 0.04). Age, delta-V, seat-belt use, and type of impact were independent predictors of Injury Severity Score (ISS). After adjusting for other modifiers, being overweight was associated with decreased ISS (p = 0.03) and abdominal maximal Abbreviated Injury Scale (mAIS) score (p = 0.008) when compared with the lean cohort. However, the lower extremity mAIS score increased when overweight (p = 0.03) and obese cohorts (p = 0.001) were compared with the lean cohort.

CONCLUSION

Although no difference in ISS was identified between the lean and obese cohorts, there was an increase in mortality with the obese cohort. The severity of lower extremity injuries increased with increasing BMI. The overweight cohort was associated with lower ISS and abdominal mAIS score compared with the lean cohort. This protection may be attributable to an increase in insulating tissue, or a "cushion effect," without a significant increase in mass and momentum.

Increased Depth of Subcutaneous Fat is Protective Against Abdominal Injuries in Motor Vehicle Collisions

Wang SC, Bednarski B, Patel S, Yan A, Kennedy T, Link E, Rowe S, Sochor M, Arbabi S.

Annu Proc Assoc Adv Automot Med. 2003;47:545-59.

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Abstract

The objective of this study was to determine the effect of differences in subcutaneous fat depth on adult injury patterns in motor vehicle collisions. Sixty-seven consecutive adult crash subjects aged 19-65 who received computed tomography of their chest, abdomen and pelvis as part of their medical evaluation and who consented to inclusion in the Crash Injury Research Engineering Network (CIREN) study were included. Subcutaneous fat was measured just lateral to the rectus abdominus muscle in a transverse section taken through the subject at the level of L4. Women had significantly greater subcutaneous fat depth than men. Increased subcutaneous fat depth was associated with significantly decreased injury severity to the abdominal region of females. A similar trend was noted in males although it did not reach statistical significance. Our findings suggest that increased subcutaneous fat may be protective against injuries by cushioning the abdominal region against injurious forces in motor vehicle collisions.

Morphomics®

Morphomics and ICAM Publications

2022

Analytic Morphomics Are Related to Outcomes After Lung Volume Reduction Surgery.

Muscle mass affects paclitaxel systemic exposure and may inform personalized paclitaxel dosing.

A correction score to compare aortic calcification in contrast enhanced and non-contrast measurements from computed tomography scans.

Healthy US population reference values for CT visceral fat measurements and the impact of IV contrast, HU range, and spinal levels.

2021

The psoas muscle index distribution and influence of outcomes in an Asian adult trauma population: an alternative indicator for sarcopenia of acute diseases.

Automated Measurements of Body Composition in Abdominal CT Scans Using Artificial Intelligence Can Predict Mortality in Patients With Cirrhosis.

Predicting outcomes of abdominal surgical emergencies in the elderly population using a CT muscle gauge.

Does a "Cushion Effect" Really Exist? A Morphomic Analysis of Vulnerable Road Users with Serious Blunt Abdominal Injury.

Field Data Study of the Effect of Knee Airbags on Lower Extremity Injury in Frontal Crashes.

Optimal body size adjustment of L3 CT skeletal muscle area for sarcopenia assessment.

2020

Gastroesophageal resuscitative occlusion of the aorta: Physiologic tolerance in a swine model of hemorrhagic shock.

Comparing FE human body model rib geometry to population data.

Morphomic calcification score from clinical CT scans: A proxy for coronary artery calcium.

CT validation of SVC-RA junction location for pediatric central line placement: is vertebral bodies below the carina accurate?

Automated measurement of muscle mass using deep learning can predict clinical outcomes in patients with liver disease.

The psoas muscle index distribution and influence of outcomes in an Asian adult trauma population: an alternative indicator for sarcopenia of acute diseases.

2019

Morphomic Index Is an Independent Predictor of Survival After Lung Cancer Resection.

Comparison of Body Size, Morphomics, and Kidney Function as Covariates of High-Dose Methotrexate Clearance in Obese Adults with Primary Central Nervous System Lymphoma.

Morphomic Factors Associated With Complete Response to Neoadjuvant Therapy in Esophageal Carcinoma.

Morphomic Signatures Derived from Computed Tomography Predict Hepatocellular Carcinoma Occurrence in Cirrhotic Patients.

Assessing Small Bowel Stricturing and Morphology in Crohn's Disease Using Semi-automated Image Analysis.

Crash Telemetry-Based Injury Severity Prediction is Equivalent to or Out-Performs Field Protocols in Triage of Planar Vehicle Collisions.

CT Correlation of Skeletal Landmarks and Vascular Anatomy in Civilian Adult Trauma Patients Implications for Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA).

An Anatomic Indexing System for Costal Cartilage and Its Application in Calcification Representation in Finite-Element Human Body Models.

Computed Tomography Evidence of Psoas Muscle Atrophy Without Concomitant Tendon Wasting in Early Sepsis.

The accuracy of local rib bone geometry measurement using full body CT images.

Validation of a DIXON-based fat quantification technique for the measurement of visceral fat using a CT-based reference standard.

Quantification of Sternum Morphomics and Injury Data.

Taking Control of Your Surgery: Impact of a Prehabilitation Program on Major Abdominal Surgery.

2018

Morphomic Malnutrition Score: A Standardized Screening Tool for Severe Malnutrition in Adults.

Measuring rib cortical bone thickness and cross section from CT.

Thoracolumbar Spine Fracture occurring in Obese People involved in Motor Vehicle Crashes.

Skeletal muscle cutoff values for sarcopenia diagnosis using T10 to L5 measurements in a healthy US population.

Measurement of Skeletal Muscle Area Improves Estimation of Aminoglycoside Clearance across Body Size

Patient Engagement Drives the Positive Impact of Prehabilitation.

Evaluating the "cushion effect" among children in frontal motor vehicle crashes

Analytic Morphomics Predict Outcomes After Lung Transplantation.

2017

Quantifying Sarcopenia Reference Values Using Lumbar and Thoracic Muscle Areas in a Healthy Population.

Calcification of costal cartilage in the adult rib cage

The Effect of Rib Fracture Pattern in the Obese

Second generation AACN injury severity prediction algorithm: development and real-world validation

Relationships of Vancomycin Pharmacokinetics to Body Size and Composition Using a Novel Pharmacomorphomic Approach Based on Medical Imaging.

The 'Cushion Effect' Is Not Protective for Children Involved in Motor Vehicle Crashes.

Morphometric age and survival following kidney transplantation.

Using Analytic Morphomics® to describe body composition associated with post-kidney transplantation diabetes mellitus.

Dorsal Muscle Attenuation May Predict Failure to Respond to Interleukin-2 Therapy in Metastatic Renal Cell Carcinoma.

The effect of age and demographics on rib shape

Body Composition Predicts Survival in Patients with Hepatocellular Carcinoma Treated with Transarterial Chemoembolization.

Can Comprehensive Imaging Analysis with Analytic Morphomics® and Geriatric Assessment Predict Serious Complications in Patients Undergoing Pancreatic Surgery?

The Michigan Surgical Home and Optimization Program is a scalable model to improve care and reduce costs.

SPECT/CT in the Evaluation of Frostbite

Personalized medicine: Enhancing our understanding of pediatric growth with Analytic Morphomics®.

Preoperative Psoas Muscle Size Predicts Postoperative Delirium in Older Adults Undergoing Surgery: A Pilot Cohort Study.

2016

Apyrase Elicits Host Antimicrobial Responses and Resolves Infection in Burns

Variation in Optimal Sagittal Alignment of the Femoral Component in Total Knee Arthroplasty

Morphomics of the Talus.

The Effect of Rib Shape on Stiffness

The role of the adaptive immune system in burn-induced heterotopic ossification and mesenchymal cell osteogenic differentiation

Application of Analytic Morphomics® for belted elderly occupants in frontal crashes

Reference Analytic Morphomics® population (RAMP): A reference to measure occupant variability for crash injury analysis

Fat Thickness as a Risk Factor for Infection in Lumbar Spine Surgery

Bone mineral density predicts posttransplant survival among hepatocellular carcinoma liver transplant recipients

Modeling female and male rib geometry with logarithmic spirals

Core muscle size and mortality following non-operative management of pelvic fractures

Body Composition Features Predict Overall Survival in Patients With Hepatocellular Carcinoma

Using Analytic Morphomics® to Understand Short-Term Convalescence after Radical Cystectomy

Early development of the mouse morphome

Investigating the clinical significance of body composition changes in patients undergoing chemoradiation for oropharyngeal cancer using Analytic Morphomics®

Factors Influencing Specificity and Sensitivity of Injury Severity Prediction (ISP) Algorithm for AACN

Psoas muscle size as a frailty measure for open and transcatheter aortic valve replacement

Analytic Morphomics®: a novel CT imaging approach to quantify adipose tissue and muscle composition in allogeneic hematopoietic cell translation

Morphomics^®

5^th International ACC Symposium: Surgical Considerations in the Treatment of Adrenocortical Carcinoma: 5^th International ACC Symposium Session: Who, When and What Combination?