Performance assessment and external validation of specific thresholds of total psoas muscle cross-sectional area as predictors of mortality in oncologic spine surgery for spinal metastases.

PURPOSE: The purpose of this study was to assess the utility of low muscle mass (LMM) in predicting 90-day and 12-month mortality after spinal tumor surgery. METHODS: We identified 115 patients operated on for spinal metastases between April 2012 and August 2022 who had available perioperative abdominal or lumbar spine CT scans and minimum 90-day follow-up. LMM was defined as a total psoas muscle cross-sectional area (TPA) at the L4 pedicle level less than 10.5 cm2 for men and less than 7.2 cm2 for women based on previously reported thresholds. A secondary analysis was performed by analyzing TPA as a continuous variable. The primary endpoint was 90-day mortality, and the secondary endpoint was 12-month mortality. Multivariate logistic regression analyses were performed. RESULTS: The 90-day mortality was 19% for patients without and 42% for patients with LMM (p = 0.010). After multivariate analysis, LMM was not independently associated with increased odds of 90-day mortality (odds ratio 2.16 [95% confidence interval 0.62 to 7.50]; p = 0.223). The 12-month mortality was 45% for patients without and 71% for patients with LMM (p = 0.024). After multivariate analysis, LMM was not independently associated with increased odds of 12-month mortality (OR 1.64 [95% CI 0.46 to 5.86]; p = 0.442). The secondary analysis showed no independent association between TPA and 90-day or 12-month mortality. CONCLUSION: Patients with LMM had higher rates of 90-day and 12-month mortality in our study, but this was not independent of other parameters such as performance status, hypoalbuminemia, or primary cancer type.

Clinical utility of psoas muscle volume in assessment of sarcopenia in patients with early-stage non-small cell lung cancer.

PURPOSE: Sarcopenia influences postoperative outcomes of patients with non-small cell lung cancer (NSCLC). Imaging tools for evaluating and diagnosing sarcopenia have developed, and a novel method of psoas volume index (PVI) obtained by measuring bilateral psoas major muscle volume has been reported. However, the relationship between sarcopenia based on PVI and clinical outcomes has not been fully investigated for patients with early-stage NSCLC. This study aimed to clarify the utility of PVI values in assessing the relationshipe between sarcopenia and clinical outcomes. METHODS: This study included 645 patients with stage I-II NSCLC who underwent curative lung resection between 2012 and 2017. Bilateral psoas major muscle volumes were calculated semi-automatically using a three-dimensional workstation. The cutoff value of PVI for defining sarcopenia was < 60.5 cm3/m3 for men and < 43.6 cm3/m3 for women. RESULTS: The avrage time to obtaine PVI was only 25 s with the 3D system, and interobserver agreements for evauating sarcopenia on PVI was 1. A total of 159 patients (24.7%) were preoperatively diagnosed with sarcopenia. On multivariate analysis, sarcopenia was an independent prognostic factor for overall survival (OS, p < 0.001), recurrence-free survival (RFS, p < 0.001), and lung cancer-specific survival (LCS, p < 0.001). The 5-year OS, RFS, and LCS were significantly worse in sarcopenic patients than non-sarcopenic patients (88.8 vs. 72.4%, p < 0.001; 80.1 vs. 65.0%, p < 0.001; 92.4 vs. 78.9%, p < 0.001, respectively). CONCLUSION: Sarcopenia diagnosed using PVI is an independent prognostic predictor of OS, RFS, and LCS in early-stage NSCLC.

Application of machine learning model to predict osteoporosis based on abdominal computed tomography images of the psoas muscle: a retrospective study.

BACKGROUND: With rapid economic development, the world's average life expectancy is increasing, leading to the increasing prevalence of osteoporosis worldwide. However, due to the complexity and high cost of dual-energy x-ray absorptiometry (DXA) examination, DXA has not been widely used to diagnose osteoporosis. In addition, studies have shown that the psoas index measured at the third lumbar spine (L3) level is closely related to bone mineral density (BMD) and has an excellent predictive effect on osteoporosis. Therefore, this study developed a variety of machine learning (ML) models based on psoas muscle tissue at the L3 level of unenhanced abdominal computed tomography (CT) to predict osteoporosis. METHODS: Medical professionals collected the CT images and the clinical characteristics data of patients over 40 years old who underwent DXA and abdominal CT examination in the Second Affiliated Hospital of Wenzhou Medical University database from January 2017 to January 2021. Using 3D Slicer software based on horizontal CT images of the L3, the specialist delineated three layers of the region of interest (ROI) along the bilateral psoas muscle edges. The PyRadiomics package in Python was used to extract the features of ROI. Then Mann-Whitney U test and the least absolute shrinkage and selection operator (LASSO) algorithm were used to reduce the dimension of the extracted features. Finally, six machine learning models, Gaussian naïve Bayes (GNB), random forest (RF), logistic regression (LR), support vector machines (SVM), Gradient boosting machine (GBM), and Extreme gradient boosting (XGBoost), were applied to train and validate these features to predict osteoporosis. RESULTS: A total of 172 participants met the inclusion and exclusion criteria for the study. 82 participants were enrolled in the osteoporosis group, and 90 were in the non-osteoporosis group. Moreover, the two groups had no significant differences in age, BMI, sex, smoking, drinking, hypertension, and diabetes. Besides, 826 radiomic features were obtained from unenhanced abdominal CT images of osteoporotic and non-osteoporotic patients. Five hundred fifty radiomic features were screened out of 826 by the Mann-Whitney U test. Finally, 16 significant radiomic features were obtained by the LASSO algorithm. These 16 radiomic features were incorporated into six traditional machine learning models (GBM, GNB, LR, RF, SVM, and XGB). All six machine learning models could predict osteoporosis well in the validation set, with the area under the receiver operating characteristic (AUROC) values greater than or equal to 0.8. GBM is more effective in predicting osteoporosis, whose AUROC was 0.86, sensitivity 0.70, specificity 0.92, and accuracy 0.81 in validation sets. CONCLUSION: We developed six machine learning models to predict osteoporosis based on psoas muscle images of abdominal CT, and the GBM model had the best predictive performance. GBM model can better help clinicians to diagnose osteoporosis and provide timely anti-osteoporosis treatment for patients. In the future, the research team will strive to include participants from multiple institutions to conduct external validation of the ML model of this study.

Sonographic assessment of low muscle quantity identifies mortality risk during COVID-19: a prospective single-centre study.

BACKGROUND: Assessment of muscle quantity by sonographic muscle indices could help identify patients at risk for fatal outcome during coronavirus disease-2019 (COVID-19). The aim of this study was to explore sonographic muscle indices as predictors of COVID-19 outcome and to test the feasibility of sonographic muscle measurement in an isolation context. METHODS: Muscle indices, derived from the psoas muscle or thigh muscles, were quantified by sonography in a cohort of patients without COVID-19 to obtain reference values for low muscle quantity. Gender-specific median of different muscle indices were defined as threshold value for low muscle quantity. The prognostic relevance of low muscle quantity, was prospectively explored in two cohorts of hospitalized COVID-19 patients. Optimal muscle index cutoff values predictive for 30 day mortality during COVID-19 were determined by receiver operating characteristic-area under the curve and Youden index calculation. Muscle quantity and known prognostic factors of COVID-19 were analysed by multivariable log-regression. RESULTS: Compared with other muscle indices, the psoas muscle area index (PMAI) showed the most favourable characteristics to predict outcome of COVID-19 disease. Sonographic morphometry of patients without COVID-19 (n = 136) revealed a gender-specific median for PMAI (male: 291.1 mm2 /m2 , female 260.6 mm2 /m2 ) as threshold value of low muscle quantity. Subsequently, COVID-19 patients (Cohort I: n = 58; Cohort II: n = 55) were prospectively assessed by bedside sonography. The studied COVID-19 patients developed a critical course of disease in 22.4% (Cohort I: n = 13/58) and 34.5% (Cohort II: n = 20/55). Mortality rate reached 12.1% (Cohort I: n = 7/58) and 20.0% (Cohort I: n = 11/55) within 30 days of follow up. COVID-19 patients with a PMAI below the gender-specific median showed a higher 30 day mortality in both COVID-19 cohorts (log rank, P < 0.05). The optimal PMAI cutoff value (206 mm2 /m2 ) predicted 30 day mortality of hospitalized COVID-19 patients with a sensitivity of 72% and specificity of 78.5% (receiver operating characteristic-area under the curve: 0.793, 95% confidence interval 0.671-0.914, P = 0.008). Multivariable log-regression analysis of PMAI, age, gender, BMI and comorbidities confirmed an independent association of low PMAI with 30 day mortality of COVID-19 patients (P = 0.018). CONCLUSIONS: Sonographic morphometry provides reliable muscle quantification under hygienic precautions and allows risk stratification of patients with COVID-19.

[Muscle assessment methods for the diagnosis of sarcopenia in cirrhotic patients]. / Métodos de evaluación muscular para el diagnóstico de sarcopenia en pacientes cirróticos.

Sarcopenia is the loss of muscle mass and function. Its presence darkens the prognosis of cirrhotic patients. The gold standard for the description of sarcopenia is the Skeletal Muscle Index (SMI). Thirty-four cirrhotic patients were included. Measurement was carried out through CT of both psoas separately that were then added obtaining the so called "sum of area of 2 psoas", in addition total muscular area, SMI and total area of psoas were measured. Ultrasonography was also performed and the transverse area of the quadriceps rectus anterior was measured by ultrasound and Hand Grip (HG). The correlation between the different measurements was analyzed comparing with the total muscle area, with quadriceps area (r = 0.39; p = 0.019), with total psoas area (r = 0.71; p <0.01), with sum of area of 2 psoas (r = 0.72; p <0.001) and with HG (r = 0.45; p = 0.0069). Compared with SMI, in women HG had 86% sensitivity and 66% specificity (AUC = 0.89). In men, the sum of 2 psoas had 91.7% sensitivity and specificity (AUC = 0.82) and the total area of psoas had 83.3% sensitivity and 76.9% specificity (AUC = 0.8). There was a very good correlation between the tomography methods with the gold standard. The correlation with ultrasound and strength was good. In the evaluation of sensitivity, specificity and AUC, it was not found a useful method when comparing with the SMI.

La sarcopenia es la pérdida de masa y función muscular. Su presencia ensombrece el pronóstico de los pacientes cirróticos. El gold standard para la descripción de sarcopenia es el Skeletal Muscle Index (SMI). Se incluyeron 34 pacientes cirróticos. Se realizó medición a través de tomografía computarizada de ambos psoas por separado, que luego fueron sumados obteniendo lo que se denominó "suma de área de 2 psoas", además se midió área muscular total, SMI y área total de psoas. También se realizó ecografía y se midió el área transversal de recto anterior del cuádriceps por ecografía y Hand Grip (HG). Se analizó la correlación entre las distintas mediciones comparando con el área muscular total, con área de cuádriceps (r = 0.39; P = 0.019), con área total de psoas (r = 0.71; P < 0.01), con suma de área de 2 psoas (r= 0.72; P < 0.001) y con HG (r = 0.45; P = 0.0069). Comparado con el SMI, en mujeres el HG tuvo 86% sensibilidad y 66% especificidad (AUC = 0.89). En hombres la suma de 2 psoas tuvo 91.7% de sensibilidad y especificidad (AUC = 0.82) y el área total de psoas tuvo 83.3% de sensibilidad y 76.9% de especificidad (AUC = 0.8). Hubo muy buena correlación entre los métodos de tomografía con el gold standard, y la correlación con la ecografía y la fuerza fue buena. Evaluando sensibilidad, especificidad y AUC, no se consideró un método útil para ambos sexos, comparado con el SMI.

The assessment of sarcopenia using psoas muscle thickness per height is not predictive of post-operative complications in IBD.

BACKGROUND: Sarcopenia is associated with postoperative complications in inflammatory bowel disease. It has most commonly been defined using the skeletal muscle index, computed after analysis of cross-sectional muscle area at L3. Psoas muscle thickness normalized to height (PMTH), which is easier to derive, is a potential surrogate of SMI and sarcopenia in patients with cirrhosis and chronic pancreatitis. We investigate whether sarcopenia defined by PMTH has utility in predicting post-operative outcomes in patients with inflammatory bowel disease. METHODS: We performed a retrospective study of adults undergoing IBD-related surgery from 2009 to 2019 at two hospitals. Sarcopenia was defined by sex-specific PMTH at the umbilicus on cross-sectional imaging using a 50th percentile median cutoff. Predictive models were created using variables (BMI, age, sex, smoking status, albumin, INR, platelets, hemoglobin, hypertension, diabetes, CAD, medications) that may be associated with complications (mortality, reoperation, readmission, transfusions, ICU admission, infection, DVT/PE), and sarcopenia for comparison. RESULTS: 85 patients with IBD were included. Lower albumin level (OR = 0.52, p = 0.039) and biologic use (OR = 5.92, p = 0.006) were associated with postoperative complications. There was no significant difference using PMTH compared to a model incorporating hypoalbuminemia and biologic use in predicting complications. Sarcopenia on univariate analysis was associated with a lower 30 day rate of reoperation (p = 0.04). CONCLUSIONS: A low status of PMTH was not associated with increased postoperative complications, however hypoalbuminemia and biologic use were. PMTH as a surrogate for sarcopenia requires further study, ideally with prospective studies comparing PMTH with accepted radiographic surrogates for sarcopenia, to determine its role in clinical decision making.

Radiographs assessment of changes in the psoas muscle at L4-L5 level after single-level lateral lumbar interbody fusion in patients with postoperative motor weakness.

The purposes of this study were (1) to investigate postoperative changes in cross-sectional area (CSA) and signal intensity (SI) of the psoas muscle (PS) using magnetic resonance imaging (MRI) and (2) to compare the CSA and SI of the PS between patients with and without motor weakness after single-level lateral lumbar interbody fusion (LLIF) at level L4-L5. Sixty patients were divided into two groups-those with postoperative motor weakness and those without-and the two groups were compared. Baseline demographics and clinical characteristics, such as operation time and blood loss, length of hospital stay, and postoperative complications, were recorded. The CSA and SI of the PS were obtained from the MRI regions of interest defined by manual tracing. Patients who developed motor weakness after surgery were significantly older (p = 0.040). The operation time (p = 0.868), LLIF operative time (p = 0.476), and estimated bleeding loss (p = 0.168) did not differ significantly between groups. In both groups, the CSA and SI of the left and right PS increased after surgery. The change in the CSA of the left PS was significantly higher in patients with weakness (247.6 ± 155.2 mm2) than without weakness (152.2 ± 133.1 mm2) (p = 0.036). The change in SI of the left PS did not differ between the two groups (p = 0.530). To prevent postoperative motor weakness regardless of the operation time, surgeons should be aware of the potential for surgical invasive of the PS during LLIF in older people.

Looking beyond the eyeball test: A novel vitality index to predict recovery after esophagectomy.

OBJECTIVES: To (1) measure 4 physiologic metrics before esophagectomy, (2) use these in an index to predict composite postoperative outcome after esophagectomy, and (3) compare predictive accuracy of this index to that of the Fried Frailty Index and Modified Frailty Index. METHODS: Grip strength (kilograms), 30-second chair sit-stands (number), 6-minute walk distance (meters), and normalized psoas muscle area (cm2/m) were measured for 77 consenting patients from January 1, 2018, to April 1, 2019. Imbalanced random forest classification estimated probability of a composite postoperative outcome, which included mortality, respiratory complications, anastomotic leak, delirium, length of stay ≥14 days, discharge to nursing facility, and readmission. G-mean error was used to compare predictive accuracy among indexes. RESULTS: Median grip strength was 38 kg (25th-75th percentiles, 31-44), number of sit-stands 11 (10-14), psoas muscle area to height ratio 6.9 cm2/m (6.0-8.2), and 6-minute walk distance 407 m (368-451). There was generally weak correlation between these metrics, with the highest between 30-second sit-stands and 6-minute walk distance (r = 0.57). Age, degree of patient-reported exhaustion, and the 4 objective metrics comprised the Esophageal Vitality Index, which had a lower G-mean error of 32% (31-33) than the Fried Frailty Index, 37% (37-38), and the Modified Frailty Index, 48% (47-48). CONCLUSIONS: The Esophageal Vitality Index, an objective, simple assessment consisting of grip strength, 30-second chair sit-stands, 6-minute walk, and psoas muscle area to height ratio outperformed commonly used frailty indexes in predicting postesophagectomy mortality and morbidity. The index provides a robust picture of patients' fitness for surgery beyond the qualitative "eyeball" test.

Feasibility of computed tomography-based assessment of skeletal muscle mass in hemodialysis patients.

BACKGROUND: Sarcopenia is a major health issue especially in patients on maintenance hemodialysis. Low skeletal muscle mass is included in the diagnostic criteria for sarcopenia. The skeletal muscle mass is usually evaluated by modalities such as bioimpedance analysis (BIA) or dual-energy X-ray absorptiometry, however the assessment of skeletal muscle mass using computed tomography (CT) images has not been established. The purpose of the study was to investigate the feasibility of the assessment of skeletal muscle mass using CT images in hemodialysis patients. METHODS: Skeletal muscle mass index (SMI) was measured by BIA and psoas muscle index (PMI) was measured by cross-sectional CT images in 131 patients. The relationship between SMI and PMI and the diagnostic ability of PMI for low muscle mass were evaluated. Furthermore, the patients were followed up and long-term survival in patients with low and high PMI were compared. RESULTS: PMI measured at the L3 vertebral level was strongly correlated with SMI (r = 0.597, p < 0.001). Age, sex, and SMI were the influencing factors for PMI. Patients with low PMI showed higher incidence rates of mortality during the follow up. CONCLUSIONS: PMI assessed by CT image can be an alternative to BIA in patients on hemodialysis.

Assessment of the cross-sectional areas of the psoas major in patients with adolescent idiopathic scoliosis before skeletal maturity.

BACKGROUND: The psoas major (PM) can support the lumbar spine and plays an important role in lumbar movement and maintaining lumbar curvature. PURPOSE: To analyze morphological changes of PM and its relation with the severity of adolescent idiopathic scoliosis (AIS). MATERIAL AND METHODS: The study was conducted on patients with AIS (age range = 10-18 years) with primary lumbar scoliosis. The cross-sectional area (CSA) of the PM at the L1-L5 levels were measured. The CSA of the PM in patients with AIS was compared with the average CSA of the PM in age-matched controls. The difference in PM at the apical vertebrae level was compared with the Cobb angle to determine the association between PM imbalance and severity of scoliosis. RESULTS: The CSA of the PM was larger on the concave side than the convex side at the apical vertebrae level and other lumber levels. Patients with a larger Cobb angle had statistically higher PM imbalance at the apical vertebrae level. The CSA of the PM on both the concave and convex sides of patients with AIS were larger than the average CSA of controls aged 16-18 years; however, there was no significant difference between patients with AIS and controls aged 10-15 years. CONCLUSION: There is a significant PM imbalance in patients with AIS before skeletal maturity, and the imbalance is related to the severity of scoliosis. The morphology of PM changed with the progression of scoliosis.

Preoperative assessment of skeletal muscle mass during magnetic resonance enterography in patients with Crohn's disease.

Measurement of the psoas muscle area has been applied to estimate lean muscle mass as a surrogate marker of sarcopenia, but there is a paucity of evidence regarding the influence of sarcopenia on clinical outcomes following inflammatory bowel disease surgery. The aim of this study was to evaluate the association between MRI enterography defined sarcopenia and postoperative complications in patients undergoing elective ileocaecal resection for Crohn's disease. To obtain cross sectional area measurement of the psoas muscle, the freehand area tool was used to trace the margin of each psoas muscle at the level of L4, with the sum recorded as Total Psoas Area (TPA). The total cross sectional muscle area of the abdominal wall was recorded as Skeletal Muscle Area (SMA), while myosteatosis was measured by normalising the psoas muscle intensity with the mean intensity of the cerebrospinal fluid. The primary outcome was the incidence of 30-day postoperative complications in patients in the lowest quartile of TPA and SMA. 31 patients were included and ten patients (32.25%) developed postoperative complications within 30 days of surgery. The cut-off values for the lowest quartile for TPA were 11.93 cm2 in men and 9.77 cm2 in women, including a total of 8 patients (25.8%) with 5 patients in this group (62.5%) developing postoperative complications and 3 patients (37.5%) Clavien-Dindo class ≥ 3 complications. The cut-off values for the lowest quartile for SMA were 73.49 cm2 in men and 65.85 cm2 in women, with 4 patients out of 8 (50%) developing postoperative complications. Psoas muscle cross sectional area and skeletal mass area can be estimated on Magnetic Resonance Enterography as surrogate markers of sarcopenia with high inter-observer agreement.

CT-based assessment of body composition following neoadjuvant chemohormonal therapy in patients with castration-naïve oligometastatic prostate cancer.

BACKGROUND: The purpose of this study is to assess the body composition changes in men with recently diagnosed oligometastatic prostate cancer following neoadjuvant chemohormonal therapy. Further, we evaluated whether CT-based body composition parameters are associated with biochemical recurrence or imaging progression. MATERIAL AND METHODS: Recently diagnosed castration-naïve oligometastatic prostate cancer patients who received neoadjuvant docetaxel chemotherapy and androgen deprivation treatment (ADT) before prostatectomy and consolidation of local and oligometastatic disease (total eradication therapy), as part of a phase-II prospective clinical trial were included. Body composition parameters including cross-sectional areas of the psoas muscle, total, visceral, and subcutaneous adipose tissue were measured on serial CT scans obtained before and following completion of neoadjuvant treatment. RESULTS: A total of 22 prostate cancer patients were included (median age 58 years, median Gleason score 8). The median time intervals between commencement of neoadjuvant chemohormonal therapy and first and second follow-up CTs were 3 and 12 months, respectively. Compared to the baseline scan, there were significant declines in psoas muscle cross-sectional areas with estimated percentage declines of -13.9% (IQR: 7.6%-16.5%, p < .001) and -13.2% (IQR: 6%-11.2%, p < .001) on first and second follow-up CTs. There were significant increases in subcutaneous adipose tissue following neoadjuvant chemohormonal therapy with percentage increases of +8.9% (IQR: 5.1%-21.5%, p = .002) and +18.9% (IQR: 6.1%-33.8%, p < .001), respectively. The median follow-up was 34.5 months. The estimated 2-year prostate-specific antigen progression-free and radiologic progression-free survival were 95.5%. No significant association between baseline or percentage change in body composition parameters and disease progression were identified. CONCLUSIONS: Our findings showed a significant reduction in muscle mass and an increase in subcutaneous adiposity in men treated with neoadjuvant docetaxel and ADT, more pronounced on the first follow-up scan after completion of neoadjuvant treatment. Body composition parameters were not found to be significant predictors of disease progression in our cohort.

Morphometric and traditional frailty assessment in transcatheter aortic valve implantation.

OBJECTIVES: Frailty is common amongst patients undergoing transcatheter aortic valve implantation (TAVI). The aim of this study was to determine the prognostic relevance of newer objective and traditional measures of frailty after TAVI. METHODS: Consecutive patients were identified from the Leeds Teaching Hospitals Trust TAVI database. Frailty was quantified objectively by measuring the total psoas muscle area (TPMA) on routine computer tomography scans and compared against Canadian Study of Health and Aging Clinical Frailty Score, Katz Index of independence in activities of daily living and Clinician Estimated Poor Mobility. Postintervention morbidity and mortality were examined between these scoring systems. RESULTS: The current study included 420 patients who had undergone TAVI between January 2013 and December 2015. Median clinical follow-up was 4.0 years (interquartile range 2.9-5.0). Standardized measurements of the TPMA were not associated with either postintervention morbidity or mortality. Only the Canadian Study of Health and Aging Clinical Frailty Score was associated with hospital stay (adjusted regression coefficient 0.70, 95% confidence interval 0.04-1.36, P = 0.038) and overall all-cause mortality (adjusted regression coefficient 1.26, 95% confidence interval 1.05-1.50, P = 0.013). There were no significant correlations between TPMA and any of the traditional frailty tools. CONCLUSION: We demonstrate TPMA to be a poor measure of patient frailty when compared with traditional methods of assessment which failed to predict postintervention outcomes. Furthermore, morphometric sarcopaenia correlated poorly with established measures of frailty.

Muscle psoas indices measured by ultrasound in cirrhosis - Preliminary evaluation of sarcopenia assessment and prediction of liver decompensation and mortality.

BACKGROUND: No data on the European population exists regarding the use of an ultrasoundbased measurement of psoas diameter for sarcopenia assessment in cirrhosis. AIMS: To determine the applicability of an ultrasound measurement of the psoas muscle diameter in patients with decompensated liver cirrhosis and to assess whether this surrogate is associated with hospitalization due to decompensation and mortality. METHODS: In 75 consecutive patients with decompensated liver cirrhosis and in 20 control subjects (January 2016 to November 2017), psoas muscle diameter was prospectively measured. The reliable measurements were used for the further analysis. Relevant clinical and laboratory data was collected. RESULTS: Ultrasound measurement was applicable in 100% of control and in 72% of study subjects. Psoas to height ratio was significantly related to hospitalization and mortality (p < 0.0001, HR 0.717, 95% CI: 0.622-0.828 and p = 0.022; HR = 0.825, 95% CI: 0.701-0.973) as was psoas muscle index (p < 0.0001, HR = 0.881, 95% CI: 0.836-0.929 and p = 0.017; HR = 0.930, 95% CI: 0.876-0.987). CONCLUSIONS: Ultrasound measurement of psoas muscle diameter and its derived indices is applicable and associated with hospitalization and mortality in patients with decompensated liver cirrhosis.

Preoperative Assessment of Muscle Mass Using Computerized Tomography Scans to Predict Outcomes Following Orthotopic Liver Transplantation.

BACKGROUND: Sarcopenia is an established risk factor predicting survival in chronically ill and trauma patients. We herein examine the assessment and clinical implication of sarcopenia in liver transplantation (LT). METHODS: Computerized tomography scans from 172 patients waitlisted for LT were analyzed by applying 6 morphometric muscle scores, including 2 density indices (psoas density [PD] and skeletal muscle density [SMD]) and 4 scores based on muscle area (total psoas area, psoas muscle index, skeletal muscle area, and skeletal muscle index). RESULTS: The prevalence of sarcopenia in our cohort ranged from 7.0% to 37.8%, depending on the score applied. Only sarcopenia as defined by the density indices PD and SMD (but not total psoas area, psoas muscle index, skeletal muscle area, or skeletal muscle index) revealed clinical relevance since it correlates significantly with postoperative complications (≥Grade III, Clavien-Dindo classification) and sepsis. Furthermore, sarcopenia predicted inferior patient and graft survival, with low muscle density (PD: <38.5 HU or SMD: <30 HU) representing an independent risk factor in a multivariate regression model (P < 0.05). Importantly, the widely used Eurotransplant donor risk index had a predictive value in nonsarcopenic patients but failed to predict graft survival in patients with sarcopenia. CONCLUSIONS: Sarcopenia revealed by low muscle density correlates with major complications following LT and acts as an independent predictor for patient and graft survival. Therefore, the application of a simple computerized tomography-morphologic index can refine an individual recipient's risk estimate in a personalized approach to transplantation.

Derivation and validation of thoracic sarcopenia assessment in patients undergoing thoracic endovascular aortic repair.

OBJECTIVE: Sarcopenia, as assessed by computed tomography (CT)-based measurements of muscle mass, is an objective and patient-specific indicator of frailty, which is an important predictor of operative morbidity and mortality. Studies to date have primarily focused on psoas-defined sarcopenia, which may not be valid among patients with thoracic aortic disease. Using psoas sarcopenia as the reference for sarcopenia, the purpose of this study was to create and to validate a new thoracic-level method of measuring sarcopenia as a novel method to assess frailty among patients undergoing thoracic endovascular aortic repair. METHODS: Prospectively collected data of patients undergoing thoracic endovascular aortic repair for thoracic aortic dissection, aneurysm, or injury using a conformable thoracic graft were reviewed. Patients with preoperative abdominal and thoracic CT imaging were included. Thoracic muscle mass was measured on axial images at the T12 level using our newly established standardized computer-assisted protocol. Psoas sarcopenia was measured at the L3 level using standard methods. Optimal sex-specific diagnostic T12 measurements were determined by receiver operating characteristic (ROC) curve analysis. A subset of scans were reviewed in duplicate by two trained observers and intraobserver and interobserver reliability tested by intraclass correlation coefficient. Agreement between T12 and L3 sarcopenia was tested by Cohen κ (scale, 0-1). RESULTS: There were 147 patients included for analysis, including 34 dissection, 80 trauma, and 33 aneurysm patients. ROC curve analysis yielded sarcopenic cutoff values of 106.00 cm2/m2 for women and 110.00 cm2/m2 for men at the T12 level. Based on ROC curve analysis, overall accuracy of T12 measurements was high (area under ROC curve, 0.91 for men and 0.90 for women). Quantitative interobserver and intraobserver reliability yielded excellent intraclass correlation coefficient values (>0.95). Qualitative interobserver reliability yielded nearly perfect Cohen κ values (>0.85). Qualitative intraobserver reliability of calculating sarcopenia at both the T12 and L3 levels was fair for both readers (0.361 and 0.288). There was additionally a general correlation between changes in muscle area at L3 with changes at T12 during 48 months. CONCLUSIONS: Thoracic sarcopenia can be readily and reliably reproduced from CT-derived measurement of T12-level muscle area. This approach may be used as an alternative method to objectively define sarcopenia in patients without abdominal CT imaging. Future studies to assess the predictability of thoracic vs abdominal sarcopenia on postoperative outcomes will enhance the utility of these tools.

Opportunistic Measurement of Skeletal Muscle Size and Muscle Attenuation on Computed Tomography Predicts 1-Year Mortality in Medicare Patients.

BACKGROUND: Opportunistic assessment of sarcopenia on CT examinations is becoming increasingly common. This study aimed to determine relationships between CT-measured skeletal muscle size and attenuation with 1-year risk of mortality in older adults enrolled in a Medicare Shared Savings Program (MSSP). METHODS: Relationships between skeletal muscle metrics and all-cause mortality were determined in 436 participants (52% women, mean age 75 years) who had abdominopelvic CT examinations. On CT images, skeletal muscles were segmented at the level of L3 using two methods: (a) all muscles with a threshold of -29 to +150 Hounsfield units (HU), using a dedicated segmentation software, (b) left psoas muscle using a free-hand region of interest tool on a clinical workstation. Muscle cross-sectional area (CSA) and muscle attenuation were measured. Cox regression models were fit to determine the associations between muscle metrics and mortality, adjusting for age, sex, race, smoking status, cancer diagnosis, and Charlson comorbidity index. RESULTS: Within 1 year of follow-up, 20.6% (90/436) participants died. In the fully-adjusted model, higher muscle index and muscle attenuation were associated with lower risk of mortality. A one-unit standard deviation (SD) increase was associated with a HR = 0.69 (95% CI = 0.49, 0.96; p = .03) for total muscle index, HR = 0.67 (95% CI = 0.49, 0.90; p < .01) for psoas muscle index, HR = 0.54 (95% CI = 0.40, 0.74; p < .01) for total muscle attenuation, and HR = 0.79 (95% CI = 0.66, 0.95; p = .01) for psoas muscle attenuation. CONCLUSION: In older adults, higher skeletal muscle index and muscle attenuation on abdominopelvic CT examinations were associated with better survival, after adjusting for multiple risk factors.

Anatomy-based MRI assessment of the iliopsoas muscle complex after pertrochanteric femoral fracture.

OBJECTIVE: To evaluate the quality of the iliopsoas muscle complex after pertrochanteric femoral fracture, using MRI; to propose an anatomy-based evaluation of the iliopsoas muscle complex; and to determine the inter-reader reliability of two classifications of fatty muscle degeneration. MATERIALS AND METHODS: We included adult patients with a displaced lesser trochanter following pertrochanteric femoral fracture. Muscle quality was evaluated using the Goutallier and Slabaugh classifications at three levels (L4/L5, L5/S1, and the anterior inferior iliac spine). Two radiologists independently reviewed the MRIs, and force measurement was performed on both hips. Linear mixed-effects models were used to determine the effect of fracture on muscle quality and strength, and Cohen's kappa statistic was used to assess inter-reader agreement. RESULTS: In the 18 patients included, the iliopsoas muscle complex showed higher grades of fatty muscle degeneration on the fractured side than on the non-fractured side. The mean difference between muscle strength on the fractured vs the non-fractured side was -12 N (p > 0.05). Inter-reader agreement for the Goutallier and Slabaugh classifications was good and very good respectively (weighted K = 0.78 and 0.85 respectively). CONCLUSION: Fatty muscle degeneration of the iliopsoas muscle complex after pertrochanteric femoral fracture was evident using both classification systems; however, fatty muscle degeneration resulted in only a minimal reduction of muscle strength. To provide a thorough assessment of iliopsoas muscle complex quality, we suggest evaluating it at different anatomical levels. Regarding inter-reader agreement, the Slabaugh classification was superior to the Goutallier classification.

Increased hospital costs are associated with low skeletal muscle mass in patients undergoing elective open aortic surgery.

OBJECTIVE: Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access. METHODS: Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis. RESULTS: We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521. CONCLUSIONS: Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients.

Assessment of the degree of abdominal myosteatosis by magnetic resonance imaging in subjects with diabetes, prediabetes and healthy controls from the general population.

OBJECTIVES: Intra- and intermyocellular lipid deposition and adipose tissue are part of glucose homeostasis and insulin resistance; however, their role in type 2 diabetes mellitus (T2DM) remains unclear. We assessed differences in the degree of abdominal myosteatosis among subjects with T2DM and prediabetes. MATERIALS AND METHODS: Asymptomatic subjects from the general population were classified as subjects with T2DM, prediabetes or healthy controls and underwent multi-echo Dixon magnetic resonance imaging (MRI) (TR 8.90 ms, six echo times, flip-angle 4°). Abdominal myosteatosis was quantified as proton-density fat-fraction (PDFFmuscle) by a standardized segmentation-algorithm. Cardiometabolic risk factors were prospectively obtained in a comprehensive health assessment and visceral and subcutaneous adipose tissue (VAT and SAT) were quantified semi-automatically. Uni- and multivariate quantile regression were used to examine associations. RESULTS: Among 349 included subjects (mean age: 56.0 ±â€¯8.0years, 56.7% males), 45 were classified as subjects with T2DM and 84 with prediabetes (12.9% and 24.1%; respectively). Median PDFFmuscle was significantly higher in subjects with T2DM and prediabetes compared to healthy controls (13.1% (IQR10.5-16.6%); 11.1% (IQR8.9-15.0%) and 10.1% (IQR7.5-13.3%); respectively, p < 0.001). The observed differences were independent of age and gender (all p < 0.002) but attenuated after adjustment for BMI (ß: -0.02, 95%CI: -1.49 to 1.44, p = 0.974; ß: 0.47, 95%CI: -0.91 to 1.86, p = 0.506; prediabetes and T2DM, respectively). This effect was attributable to VAT, which remained independently associated with PDFFmuscle after full adjustment (ß: 0.01, 95%CI: 0.01-0.02, p = 0.002). CONCLUSIONS: There are significant differences in the degree of abdominal myosteatosis between subjects with T2DM, prediabetes and healthy controls, that may be confounded by VAT. However, abdominal myosteatosis by MRI might serve as a cardiometabolic imaging-biomarker, specifically in the setting of impaired glucose metabolism.