Leon Lenchik

All Publications

• Effect of protein supplementation on hip bone mineral density, cortical thickness, and bone strength in older adult participants during a caloric restriction and aerobic exercise weight loss intervention: a randomized controlled trial OSTEOPOROSIS INTERNATIONAL Weaver, A. A., Greene, K. A., Leng, X., Lenchik, L., Lyles, M. F., Nicklas, B. J., Baker, A. M., Helgason, B., Stapleton, J., Devane, K., Shapses, S. A., Houston, D. K. 2026

  Abstract

  Weight loss in older age can cause bone loss. In older adults with overweight/obesity in a weight loss trial, 6-month hip bone strength increased with higher protein intake versus controls consuming the Recommended Dietary Allowance. However, greater weight loss was associated with greater 18-month hip bone mineral density loss.Weight loss (WL) to treat obesity in older age can exacerbate bone loss.This trial assessed the effects of higher protein intake on hip bone outcomes in 187 older adults with overweight/obesity participating in 6 months of active WL (caloric restriction + aerobic exercise) followed by a 12-month maintenance phase. Participants were randomized to either the Recommended Dietary Allowance for protein intake of 0.8 g protein/kg body weight/day (RecProt) or higher protein intake of 1.2 g protein/kg/day for the 6-month WL period only (6-mo HiProt) or the full 18-month period (18-mo HiProt). CT scans at baseline, 6 months, and 18 months were analyzed for hip volumetric bone mineral density (vBMD) and cortical thickness; bone strength was assessed via finite element modeling of a sideways fall. Areal (a)BMD was measured with hip dual-energy X-ray absorptiometry. Analyses examined 6-month and 18-month bone changes using analysis of covariance, and Spearman's correlations of WL vs. bone changes.Greater WL was associated with greater gains in hip bone strength (p = 0.007) at 6 months, but greater trabecular vBMD loss at 18 months (p = 0.011) and aBMD loss at 6 and 18 months (p < 0.001). Hip bone strength increased 3.8 ± 1.7% over 6 months in the 18-mo HiProt group vs. 0.5 ± 1.6% in the RecProt group (p = 0.02) despite similar 6-month WL across groups (-8.0 ± 5.0%); however, there were no differences between the other groups. Eighteen-month group differences were non-significant.Higher protein intake had a beneficial effect on hip bone strength in older adults with overweight/obesity undergoing a WL intervention over the short-term.

  View details for DOI 10.1007/s00198-026-07845-6

  View details for Web of Science ID 001664794200001

  View details for PubMedID 41553490

  View details for PubMedCentralID 4016236

• Association of computed tomography (CT)-derived muscle area and density at multiple sites with 10-year fracture risk in older men JBMR PLUS Hetherington-Rauth, M., Mansfield, T. A., Lenchik, L., Weaver, A. A., Strotmeyer, E. S., Orwoll, E. S., Cawthon, P. M. 2026; 10 (1): ziaf169

  Abstract

  Loss of muscle quantity and quality with age has been related to fracture risk independent of areal BMD (aBMD) assessed by DXA. Automated approaches to assess muscle on CT images make it more feasible to assess associations of muscle quantity (cross-sectional area) and quality (density) of multiple anatomical regions on fracture risk. We investigated whether automated analysis of muscle area and density at the trunk (L1 and L3) and proximal thigh (right and left) predicted 10-yr fracture risk (any clinical, clinical spine, and non-spine) independent of DXA aBMD as well as CT vBMD and muscle function in older men from the Osteoporotic Fractures in Men (MrOS) study. Men with CT imaging and complete covariate measures were included (n = 3237, 73.7 ± 5.9 yr). Fractures were centrally adjudicated. Proportional hazards models assessed relationships, adjusting for DXA FN aBMD, CT FN vBMD, CT LS vBMD, and muscle function. For any fracture, a 10%-25% and 8%-12% risk reduction was observed per 1-SD increment in muscle area and density, respectively, across anatomical locations, though HR estimates only reached significance for muscle area at the thigh and muscle density at the Trunk-L3 (p > .05), despite overlapping 95% CIs across anatomical sites. Similar reductions were seen for non-spine fractures. For spine fracture, only Trunk-L3 muscle density had a significant 31% risk reduction. For hip fracture, muscle area at the right (40%) and left thigh (35%) and muscle density at Trunk-L3 (25%) were associated with reduced risk (p < .05). Results remained unchanged or slightly attenuated after adjusting for muscle function and BMD, respectively. Automated measures of muscle area and density on CT images may enhance fracture risk assessment in older men that does not vary substantially across different anatomic locations. The relative importance of muscle area and density for fracture risk prediction varies across fracture types.

  View details for DOI 10.1093/jbmrpl/ziaf169

  View details for Web of Science ID 001654785500001

  View details for PubMedID 41503149

  View details for PubMedCentralID PMC12771367

• Cost-effectiveness of opportunistic CT versus clinical methods for sarcopenia screening. Skeletal radiology Padwal, J., Hanly, A., Johnston, A., Lenchik, L., Gyftopoulos, S., Boutin, R. D. 2025

  Abstract

  To evaluate the cost-effectiveness of opportunistic CT for sarcopenia screening compared with standard-of-care clinical screening methods, using a decision-analytic model based on quality-adjusted life years (QALYs) and healthcare costs.We developed a decision-analytic model simulating a hypothetical cohort of 70-year-old male patients at risk for sarcopenia over a 3-year time horizon from a US healthcare system perspective. The model compared two screening strategies: standard-of-care clinical evaluation per EWGSOP2 guidelines (physical exam + DXA evaluation of lean mass) and opportunistic CT as measures of muscle mass and quality. Model inputs-including screening sensitivities/specificities, costs, utility values, and probabilities of cardiovascular complications-were derived from published literature. Incremental cost-effectiveness ratio (ICER) and net monetary benefit (NMB) were calculated, and sensitivity analyses were performed to assess the robustness of findings across variable inputs.Opportunistic CT was the favored strategy, with lower costs ($845 vs. $1,295), comparable effectiveness (0.87 QALYs), and higher net monetary benefit ($86,037 vs. $85,588) relative to the standard-of-care strategy. The standard-of-care strategy's ICER was $47.7 million per QALY, exceeding our willingness-to-pay threshold of $100,000. Probabilistic sensitivity analysis across 100,000 simulations demonstrated that opportunistic CT was favored across all tested willingness-to-pay thresholds up to $200,000.Opportunistic CT is a cost-effective strategy for sarcopenia screening, offering similar effectiveness at a lower cost compared to the standard-of-care approach. By leveraging existing imaging studies, opportunistic CT screening has the potential to enhance early detection and decrease the underdiagnosis of sarcopenia while also reducing the burden of additional DXA scans and clinical visits.

  View details for DOI 10.1007/s00256-025-05084-0

  View details for PubMedID 41266853

  View details for PubMedCentralID 7446889

• Defining Reference Values for Skeletal Muscle Metrics on Abdominal CT Using Data From Healthy Young Adult Populations: A Systematic Review and Meta-Analysis. AJR. American journal of roentgenology Ju, C., Yao, L., Yoon, S. Y., Lenchik, L., Johnston, A., Derry, L. T., Hom, J., Svec, D., Chaudhari, A. S., Boutin, R. D. 2025

  Abstract

  BACKGROUND. CT muscle metrics hold promise for opportunistic sarcopenia screening and individualized clinical risk stratification, but reference values applicable across broad populations are lacking. OBJECTIVE. To estimate reference cutoff values for CT skeletal muscle metrics using data from populations of healthy young adults. EVIDENCE ACQUISITION. The PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases were searched through January 1, 2025 for studies reporting skeletal muscle index (SMI) and/or skeletal muscle density (SMD) on CT at the L3 vertebral level in healthy young adults (age range, 18-45 years). For SMI and SMD in both men and women, a random effects meta-analysis was used to estimate interstudy SD (as a measure of variance among studies) and mean values for a theoretic global population of healthy young adults. Presence of significant heterogeneity among individual study means was assessed using the Q statistic. Cutoff values for the theoretic global population corresponding with a T-score of -2 (i.e., values ≥ 2 SDs below the population's mean value) were calculated, incorporating the meta-analysis results and pooled intrastudy variance. EVIDENCE SYNTHESIS. The meta-analysis included 14 studies (16,958 individuals; 11,819 men, 5139 women) reporting SMI, of which seven studies (11,175 individuals; 8372 men, 2803 women) also reported SMD. The estimated global mean value for SMI was 54.6 in men and 42.4 in women and for SMD was 47.4 HU in men and 43.6 HU in women. The interstudy SD for SMI was 5.4 in men and 4.3 in women and for SMD was 1.9 in men versus 3.2 in women; significant heterogeneity was present among individual study means for both SMI and SMD in both men and women (all p<.001). The cutoff value corresponding with a T-score of -2 for SMI was 36.3 in men and 27.5 in women and for SMD was 36.4 HU in men and 28.1 HU in women. CONCLUSION. This meta-analysis of studies performed in healthy young adults provides reference mean values and standardized cutoffs analogous to a T-score of -2 for SMI and SMD at the L3 level on abdominal CT. CLINICAL IMPACT. These results can aid opportunistic screening for sarcopenia.

  View details for DOI 10.2214/AJR.25.32781

  View details for PubMedID 40334088

• ACR Appropriateness Criteria® Suspected Primary Bone Tumors: 2024 Update. Journal of the American College of Radiology : JACR Ahlawat, S., Lenchik, L., Baker, J. C., Allen, H., Banks, J., Florou, V., Garner, H. W., Hammer, M. R., Hiniker, S. M., Kamel, S. I., Lu, Y., Peairs, K. S., Scott, J. A., Wessell, D. E. 2025; 22 (5S): S440-S454

  Abstract

  Despite the rarity of primary bone tumors, appropriate imaging evaluation is essential for diagnosis and management. Radiographs are the most appropriate initial imaging study for detection and characterization of the majority of primary bone tumors. Radiographs often provide sufficient information for the diagnosis of primary bone tumors, however, for radiographically occult primary bone tumors, MRI and/or CT can be performed. For indeterminate or aggressive bone tumors on radiographs, MRI or CT are typically the most appropriate next step for the evaluation of anatomic extent, assessment of viability and biopsy or surgical planning. This document focuses on five common variants to guide diagnosis and management of primary bone tumors. In addition to conventional radiographs, appropriate use of MRI, CT, PET/CT, bone scan, image-guided biopsy and ultrasound are discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

  View details for DOI 10.1016/j.jacr.2025.02.020

  View details for PubMedID 40409893

• Sarcopenia Diagnosis Trends and Opportunistic Use of Abdominal CT Among Medicare Beneficiaries. Journal of the American College of Radiology : JACR Christensen, E. W., Drake, A. R., Lenchik, L., Boutin, R. D. 2025

  Abstract

  To estimate the share of the Medicare fee-for-service population with sarcopenia compared with osteoporosis, an associated age-related disease, using claims data and to assess abdominal CT use in the diagnosis of sarcopenia compared with dual-energy x-ray absorptiometry for the diagnosis of osteoporosis.This retrospective study used a nationally representative 5% sample of Medicare fee-for-service beneficiaries from CMS (2017-2022). Diagnostic trends for sarcopenia and osteoporosis were compared. Nonlinear regression was used to assess the temporal association of the number of beneficiaries with an abdominal CT and a sarcopenia diagnosis (compared with dual-energy x-ray absorptiometry and osteoporosis diagnosis). Multivariable logistic regression models controlling for gender, age, race or ethnicity, urbanicity, area deprivation, and comorbidities assessed the likelihood of imaging associated with the diagnosis.For 11,801,012 beneficiary years, there were 2,849,547 unique beneficiaries (53.2% female). Beneficiaries diagnosed with sarcopenia increased 480% from 0.01% in 2017 to 0.07% in 2022. From 90 days before the diagnosis date, the number of beneficiaries with an abdominal CT scan increased from the baseline rate at an exponential rate. After the diagnosis, the number of beneficiaries with abdominal CT scans was also elevated and returned to the baseline rate by 90 days after the diagnosis. These nonlinear patterns are statistically different from the null hypothesis of a flat line, which is indicative of no temporal association.Although the diagnostic rate for sarcopenia increased nearly 5-fold from 2017 to 2022, it remains underdiagnosed. The results provide evidence that abdominal CT (used opportunistically or intentionally) may contribute to diagnosing sarcopenia.

  View details for DOI 10.1016/j.jacr.2025.03.001

  View details for PubMedID 40243970

• Sarcopenia, Obesity, and Sarcopenic Obesity: Retrospective Audit of Electronic Health Record Documentation versus Automated CT Analysis in 17 646 Patients. Radiology Zambrano Chaves, J. M., Hom, J., Lenchik, L., Chaudhari, A. S., Boutin, R. D. 2025; 315 (1): e243525

  View details for DOI 10.1148/radiol.243525

  View details for PubMedID 40232143

• Effect of baseline geriatric and quality of life assessments on treatment outcomes in ECOG-ACRIN EA2186 (GIANT): A randomized phase II study of gemcitabine and nab-paclitaxel compared with 5-fluorouracil, leucovorin, and liposomal irinotecan in older patients with treatment-naïve metastatic pancreatic cancer. Dotan, E., Catalano, P. J., Lenchik, L., Boutin, R., Yao, X., Ohr, J., Lim, K., Fisher Jr, G. A., Vijayvergia, N., Chandana, S. R., Kalyan, A., Dunne, R., Zhen, D., Li, D., Reiss, K., Simon, M. A., Berlin, J., Wagner, L. I., O'Dwyer, P. J. LIPPINCOTT WILLIAMS & WILKINS. 2025

  View details for DOI 10.1200/JCO.2025.43.4_suppl.676

  View details for Web of Science ID 001417522100020

• Opportunistic Screening of Bone Fragility Using Computed Tomography. Seminars in musculoskeletal radiology Acevedo, J. B., Lenchik, L., Weaver, A. A., Boutin, R. D., Wuertzer, S. 2024; 28 (5): 620-627

  Abstract

  Opportunistic screening uses existing imaging studies for additional diagnostic insights without imposing further burden on patients. We explore the potential of opportunistic computed tomography (CT) screening for osteoporosis, a condition affecting 500 million people globally and leading to significant health care costs and fragility fractures. Although dual-energy X-ray absorptiometry (DXA) remains the gold standard for diagnosing osteoporosis, > 50% of fractures occur in individuals not screened previously with DXA. With recent advancements in technology, CT has emerged as the most promising tool for opportunistic screening due to its wide use and the ability to provide quantitative measurements of bone attenuation, a surrogate of bone mineral density. This article discusses the technical considerations, calibration methods, and potential benefits of CT for osteoporosis screening. It also explores the role of automation, supervised and unsupervised, in streamlining the diagnostic process, improving accuracy, and potentially developing new biomarkers of bone health. The potential addition of radiomics and genomics is also highlighted, showcasing the synergy between genetic and imaging data for a more comprehensive understanding of osteoporosis pathophysiology and with it possible novel osteoporosis therapies. The future of opportunistic CT screening holds significant promise, with automation and advanced image processing ultimately enhancing patient care, reducing rates of osteoporotic fractures, and improving patient outcomes.

  View details for DOI 10.1055/s-0044-1788816

  View details for PubMedID 39406224

• A randomized phase II study of gemcitabine and nab-paclitaxel compared with 5-fluorouracil, leucovorin, and liposomal irinotecan in older patients with treatment-naive metastatic pancreatic cancer (GIANT): ECOG-ACRIN EA2186. Dotan, E., Catalano, P. J., Lenchik, L., Boutin, R., Yao, X., Ohr, J., Lim, K., Vijayvergia, N., Chandana, S. R., Kalyan, A., Dunne, R., Zhen, D., Li, D., Simon, M. A., Berlin, J., Wagner, L. I., O'Dwyer, P. J. LIPPINCOTT WILLIAMS & WILKINS. 2024

  View details for Web of Science ID 001275557400878

• Abdominal CT metrics in 17,646 patients reveal associations between myopenia, myosteatosis, and medical phenotypes: a phenome-wide association study EBIOMEDICINE Chaves, J., Lenchik, L., Gallegos, I. O., Blankemeier, L., Liang, T., Rubin, D. L., Willis, M. H., Chaudhari, A. S., Boutin, R. D. 2024; 103

  View details for DOI 10.1051161016/j.ebiom.2024.105116

  View details for Web of Science ID 001231570700001

• Abdominal CT metrics in 17,646 patients reveal associations between myopenia, myosteatosis, and medical phenotypes: aphenome-wide association study. EBioMedicine Zambrano Chaves, J. M., Lenchik, L., Gallegos, I. O., Blankemeier, L., Rubin, D. L., Willis, M. H., Chaudhari, A. S., Boutin, R. D. 2024; 103: 105116

  Abstract

  BACKGROUND: Deep learning facilitates large-scale automated imaging evaluation of body composition. However, associations of body composition biomarkers with medical phenotypes have been underexplored. Phenome-wide association study (PheWAS) techniques search for medical phenotypes associated with biomarkers. A PheWAS integrating large-scale analysis of imaging biomarkers and electronic health record (EHR) data could discover previously unreported associations and validate expected associations. Here we use PheWAS methodology to determine the association of abdominal CT-based skeletal muscle metrics with medical phenotypes in a large North American cohort.METHODS: An automated deep learning pipeline was used to measure skeletal muscle index (SMI; biomarker of myopenia) and skeletal muscle density (SMD; biomarker of myosteatosis) from abdominal CT scans of adults between 2012 and 2018. A PheWAS was performed with logistic regression using patient sex and age as covariates to assess for associations between CT-derived muscle metrics and 611 common EHR-derived medical phenotypes. PheWAS P values were considered significant at a Bonferroni corrected threshold (alpha=0.05/1222).FINDINGS: 17,646 adults (mean age, 56 years±19 [SD]; 57.5% women) were included. CT-derived SMI was significantly associated with 268 medical phenotypes; SMD with 340 medical phenotypes. Previously unreported associations with the highest magnitude of significance included higher SMI with decreased cardiac dysrhythmias (OR [95% CI], 0.59 [0.55-0.64]; P<0.0001), decreased epilepsy (OR, 0.59 [0.50-0.70]; P<0.0001), and increased elevated prostate-specific antigen (OR, 1.84 [1.47-2.31]; P<0.0001), and higher SMD with decreased decubitus ulcers (OR, 0.36 [0.31-0.42]; P<0.0001), sleep disorders (OR, 0.39 [0.32-0.47]; P<0.0001), and osteomyelitis (OR, 0.43 [0.36-0.52]; P<0.0001).INTERPRETATION: PheWAS methodology reveals previously unreported associations between CT-derived biomarkers of myopenia and myosteatosis and EHR medical phenotypes. The high-throughput PheWAS technique applied on a population scale can generate research hypotheses related to myopenia and myosteatosis and can be adapted to research possible associations of other imaging biomarkers with hundreds of EHR medical phenotypes.FUNDING: National Institutes of Health, Stanford AIMI-HAI pilot grant, Stanford Precision Health and Integrated Diagnostics, Stanford Cardiovascular Institute, Stanford Center for Digital Health, and Stanford Knight-Hennessy Scholars.

  View details for DOI 10.1016/j.ebiom.2024.105116

  View details for PubMedID 38636199

• Body composition measurements and clinical outcomes in patients with resectable pancreatic adenocarcinoma - analysis from SWOG S1505. Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract Sohal, D. P., Boutin, R. D., Lenchik, L., Kim, J., Beg, M. S., Wang-Gillam, A., Wade, J. L., Guthrie, K. A., Chiorean, E. G., Ahmad, S. A., Lowy, A. M., Philip, P. A., Chang, V. T. 2024; 28 (3): 232-235

  Abstract

  BACKGROUND: Sarcopenic obesity and muscle attenuation have been associated with survival in patients with borderline resectable and advanced pancreatic ductal adenocarcinoma (PDA); however, these relationships are unknown for patients with resectable PDA. This study examined the associations between skeletal muscle and adipose tissue as measured on baseline computed tomography (CT) and the overall survival (OS) of participants with resectable PDA in a secondary analysis of the Southwest Oncology Group S1505 clinical trial (identifier: NCT02562716).METHODS: The S1505 phase II clinical trial enrolled patients with resectable PDA who were randomized to receive modified FOLFIRINOX or gemcitabine and nab-paclitaxel as perioperative chemotherapy, followed by surgical resection. Baseline axial CT images at the L3 level were analyzed with externally validated software, and measurements were recorded for skeletal muscle area and skeletal muscle density, visceral adipose tissue area (VATA) and density, and subcutaneous adipose tissue area and density. The relationships between CT metrics and OS were analyzed using Cox regression models, with adjustment for baseline participant characteristics.RESULTS: Of 98 eligible participants with available baseline abdominal CT, 8 were excluded because of imaging quality (eg, orthopedic hardware), resulting in 90 evaluable cases: 51 men (57.0%; mean age, 63.2 years [SD, 8.5]; mean body mass index [BMI], 29.3kg/m2 [SD, 6.4]), 80 White (89.0%), 6 Black (7.0%), and 4 unknown race (4.0%). Sarcopenia was present in 32 participants (35.9%), and sarcopenic obesity was present in 10 participants (11.2%). Univariable analyses for the 6 variables of interest indicated that the standardized mean difference (hazard ratio [HR], 0.75; 95% CI, 0.57-0.98; P=.04) was statistically significantly associated with OS. In models adjusted for sex, race, age, BMI, performance score, contrast use, sarcopenia, and sarcopenic obesity, VATA was statistically significantly associated with OS (HR, 1.58; 95% CI, 1.00-2.51; P=.05). No difference was observed in OS between participants according to sarcopenic obesity or sarcopenia categories. The median OS estimates were 25.1 months for participants without sarcopenic obesity, 18.6 months for participants with sarcopenic obesity, 23.6 months for participants without sarcopenia, and 27.9 months for participants with sarcopenia.CONCLUSION: This was the first study to systematically evaluate body composition parameters in a prospective multicenter trial of patients with resectable PDA who received perioperative chemotherapy. Visceral adipose tissue was associated with survival; however, there was no association between OS and sarcopenia or sarcopenic obesity. Further studies should evaluate these findings in more detail.

  View details for DOI 10.1016/j.gassur.2023.12.022

  View details for PubMedID 38445914

• Biomarkers of Body Composition. Seminars in musculoskeletal radiology Chang, C. Y., Lenchik, L., Blankemeier, L., Chaudhari, A. S., Boutin, R. D. 2024; 28 (1): 78-91

  Abstract

  The importance and impact of imaging biomarkers has been increasing over the past few decades. We review the relevant clinical and imaging terminology needed to understand the clinical and research applications of body composition. Imaging biomarkers of bone, muscle, and fat tissues obtained with dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging, and ultrasonography are described.

  View details for DOI 10.1055/s-0043-1776430

  View details for PubMedID 38330972

• Skeletal Muscle Area on CT: Determination of an Optimal Height Scaling Power and Testing for Mortality Risk Prediction. AJR. American journal of roentgenology Blankemeier, L., Yao, L., Long, J., Reis, E. P., Lenchik, L., Chaudhari, A. S., Boutin, R. D. 2023

  Abstract

  BACKGROUND: Sarcopenia is commonly assessed on CT using the skeletal muscle index (SMI), calculated as skeletal muscle area (SMA) at L3 divided by patient height squared (i.e., height scaling power of 2). OBJECTIVE: To determine the optimal height scaling power for SMA measurements on CT, and to test the influence of the derived optimal scaling power on the utility of SMI in predicting all-cause mortality. METHODS: This retrospective study included 16,575 patients (mean age, 56.4 years; 6985 men, 9590 women) who underwent abdominal CT from December 2012 through October 2018. SMA at L3 was determined using automated software. The sample was stratified into 5459 patients without major medical conditions (using ICD-9 and ICD-10 codes) for determining an optimal height scaling power, and 11,116 patients with major medical conditions for testing this power. The optimal scaling power was determined by allometric analysis (whereby regression coefficients were fitted to log-linear sex-specific models relating height to SMA) and by analysis of statistical independence of SMI from height across scaling powers. Cox proportional hazards models were used to test the derived optimal scaling power's influence on utility of SMI in predicting all-cause mortality. RESULTS: In allometric analysis, the regression coefficient of log(height) in patients ≤40 years was 1.02 in men and 1.08 in women, and in patients >40 years was 1.07 in men and 1.10 in women (all p<.05 vs regression coefficient of 2). In analyses for statistical independence of SMI from height, the optimal height scaling power (i.e., those yielding correlations closest to 0) was, in patients ≤40 years, 0.97 in men and 1.08 in women, and in patients >40 years, 1.03 in men and 1.09 in women. In the Cox model used for testing, SMI predicted all-cause mortality with greater concordance index using a height scaling power of 1 than 2 in men (0.675 vs 0.663, p<.001) and women (0.664 vs 0.653, p<.001). CONCLUSION: The findings support a height scaling power of 1, rather than conventional power of 2, for SMI computation. CLINICAL IMPACT: A revised height scaling power for SMI could impact the utility of CT-based sarcopenia diagnoses in risk assessment.

  View details for DOI 10.2214/AJR.23.29889

  View details for PubMedID 37877596

• Clinical, functional, and opportunistic CT metrics of sarcopenia at the point of imaging care: analysis of all-cause mortality SKELETAL RADIOLOGY Yao, L., Petrosyan, A., Chaudhari, A. J., Lenchik, L., Boutin, R. D. 2023

  View details for DOI 10.1007/s00256-023-04438

  View details for Web of Science ID 001061575900001

• Clinical, functional, and opportunistic CT metrics of sarcopenia at the point of imaging care: analysis of all-cause mortality. Skeletal radiology Yao, L., Petrosyan, A., Chaudhari, A. J., Lenchik, L., Boutin, R. D. 2023

  Abstract

  This study examines clinical, functional, and CT metrics of sarcopenia and all-cause mortality in older adults undergoing outpatient imaging.The study included outpatients ≥ 65 years of age undergoing CT or PET/CT at a tertiary care institution. Assessments included screening questionnaires for sarcopenia (SARC-F) and frailty (FRAIL scale), and measurements of grip strength and usual gait speed (6 m course). Skeletal muscle area (SMA), index (SMI, area/height2) and density (SMD) were measured on CT at T12 and L3. A modified SMI was also examined (SMI-m, area/height). Mortality risk was studied with Cox proportional hazard analysis.The study included 416 patients; mean age 73.8 years [sd 6.2]; mean follow-up 2.9 years (sd 1.34). Abnormal grip, SARC-F, and FRAIL scale assessments were associated with higher mortality risk (HR [95%CI] = 2.0 [1.4-2.9], 1.6 [1.1-2.3], 2.0 [1.4-2.8]). Adjusting for age, higher L3-SMA, T12-SMA, T12-SMI and T12-SMI-m were associated with lower mortality risk (HR [95%CI] = 0.80 [0.65-0.90], 0.76 [0.64-0.90], 0.84 [0.70-1.00], and 0.80 [0.67-0.90], respectively). T12-SMD and L3-SMD were not predictive of mortality. After adjusting for abnormal grip strength and FRAIL scale assessments, T12-SMA and T12-SMI-m remained predictive of mortality risk (HR [95%CI] = 0.83 [0.70-1.00] and 0.80 [0.67-0.97], respectively).CT areal metrics were weaker predictors of all-cause mortality than clinical and functional metrics of sarcopenia in our older patient cohort; a CT density metric (SMD) was not predictive. Of areal CT metrics, SMI (area/height2) appeared to be less effective than non-normalized SMA or SMA normalized by height1.

  View details for DOI 10.1007/s00256-023-04438-w

  View details for PubMedID 37684434

  View details for PubMedCentralID 9891989

• Muscle Steatosis and Fibrosis in Older Adults, From the AJR Special Series on Imaging of Fibrosis. AJR. American journal of roentgenology Lenchik, L., Mazzoli, V., Cawthon, P. M., Hepple, R. T., Boutin, R. D. 2023

  Abstract

  The purpose of this article is to review steatosis and fibrosis of skeletal muscle, focusing on older adults. Although CT, MRI, and ultrasound are commonly used to image skeletal muscle and provide diagnoses for a variety of medical conditions, quantitative assessment of muscle steatosis and fibrosis is uncommon. This review provides radiologists with a broad perspective on muscle steatosis and fibrosis in older adults by considering their public health impact, biologic mechanisms, and evaluation using CT, MRI, and ultrasound. Promising directions in clinical research that employ artificial intelligence algorithms and the imaging assessment of biologic age are also reviewed. The presented imaging methods hold promise for improving the evaluation of common conditions affecting older adults including sarcopenia, frailty, and cachexia.

  View details for DOI 10.2214/AJR.23.29742

  View details for PubMedID 37610777

• Association of CT-Derived Skeletal Muscle and Adipose Tissue Metrics with Frailty in Older Adults. Academic radiology Bunch, P. M., Rigdon, J., Niazi, M. K., Barnard, R. T., Boutin, R. D., Houston, D. K., Lenchik, L. 2023

  Abstract

  RATIONALE AND OBJECTIVES: Tools are needed for frailty screening of older adults. Opportunistic analysis of body composition could play a role. We aim to determine whether computed tomography (CT)-derived measurements of muscle and adipose tissue are associated with frailty.MATERIALS AND METHODS: Outpatients aged ≥55 years consecutively imaged with contrast-enhanced abdominopelvic CT over a 3-month interval were included. Frailty was determined from the electronic health record using a previously validated electronic frailty index (eFI). CT images at the level of the L3 vertebra were automatically segmented to derive muscle metrics (skeletal muscle area [SMA], skeletal muscle density [SMD], intermuscular adipose tissue [IMAT]) and adipose tissue metrics (visceral adipose tissue [VAT], subcutaneous adipose tissue [SAT]). Distributions of demographic and CT-derived variables were compared between sexes. Sex-specific associations of muscle and adipose tissue metrics with eFI were characterized by linear regressions adjusted for age, race, ethnicity, duration between imaging and eFI measurements, and imaging parameters.RESULTS: The cohort comprised 886 patients (449 women, 437 men, mean age 67.9 years), of whom 382 (43%) met the criteria for pre-frailty (ie, 0.10< eFI ≤ 0.21) and 138 (16%) for frailty (eFI > 0.21). In men, 1 standard deviation changes in SMD (beta = -0.01, 95% confidence interval [CI],-0.02 to-0.001, P=.02) and VAT area (beta = 0.008, 95% CI,0.0005-0.02, P=.04), but not SMA, IMAT, or SAT, were associated with higher frailty. In women, none of the CT-derived muscle or adipose tissue metrics were associated with frailty.CONCLUSION: We observed a positive association between frailty and CT-derived biomarkers of myosteatosis and visceral adiposity in a sex-dependent manner.

  View details for DOI 10.1016/j.acra.2023.06.003

  View details for PubMedID 37479618

• The GIANT trial (ECOG-ACRIN EA2186) methods paper: A randomized phase II study of gemcitabine and nab-paclitaxel compared with 5-fluorouracil, leucovorin, and liposomal irinotecan in older patients with treatment-naïve metastatic pancreatic cancer - defining a new treatment option for older vulnerable patients. Journal of geriatric oncology Dotan, E., Catalano, P., Lenchik, L., Boutin, R., Yao, X., Marques, H. S., Ioffe, D., Zhen, D. B., Li, D., Wagner, L. I., Simon, M. A., Wong, T. Z., O'Dwyer, P. J. 2023; 14 (3): 101474

  Abstract

  Pancreatic cancer is the fourth leading cause of cancer-related death in the US with an increasing incidence in older adults (OA) over age 70. There are currently no treatment guidelines for OA with metastatic pancreatic cancer (mPCA) and selecting a chemotherapy regimen for these patients is subjective, based largely on chronologic age and performance status (PS). Geriatric screening tools provide a more objective and accurate evaluation of a patient's overall health but have not yet been validated in patient selection for mPCA treatment. This study aims to elucidate the optimal chemotherapy treatment of vulnerable OA with mPCA and understand the geriatric factors that affect outcomes in this population.The GIANT (ECOG-ACRIN EA2186) study is multicenter, randomized phase II trial enrolling patients over age 70 with newly diagnosed mPCA. This study utilizes a screening geriatric assessment (GA) which characterizes patients as fit, vulnerable, or frail. Patients with mild abnormalities in functional status and/or cognition, moderate comorbidities, or over age 80 are considered vulnerable. Enrolled patients are randomized to one of two dose-reduced treatment regimens (gemcitabine/nab-paclitaxel every other week, or dose-reduced 5-fluoruracil (5FU)/ liposomal irinotecan (nal-IRI) every other week). GA and quality of life (QoL) evaluations are completed prior to treatment initiation and at each disease evaluation. Overall survival (OS) is the primary endpoint, with secondary endpoints including progression free survival (PFS) and objective response rate (ORR). Enrolled patients will be stratified by age (70-74 vs ≥75) and ECOG PS (0-1 vs 2). Additional endpoints of interest for OA include evaluation of risk factors identified through GA, QoL evaluation, and toxicities of interest for older adults. Correlative studies include assessment of pro-inflammatory biomarkers of aging in the blood (IL-6, CRP) and imaging evaluation of sarcopenia as predictors of treatment tolerance.The GIANT study is the first randomized, prospective national trial evaluating vulnerable OA with mPCA aimed at developing a tailored treatment approach for this patient population. This trial has the potential to establish a new way of objectively selecting vulnerable OA with mPCA for modified treatment and to establish a new standard of care in this growing patient population.This trial is registered with ClinicalTrial.gov Identifier NCT04233866.

  View details for DOI 10.1016/j.jgo.2023.101474

  View details for PubMedID 36963200

• Improving Data-Efficiency and Robustness of Medical Imaging Segmentation Using Inpainting-Based Self-Supervised Learning. Bioengineering (Basel, Switzerland) Dominic, J., Bhaskhar, N., Desai, A. D., Schmidt, A., Rubin, E., Gunel, B., Gold, G. E., Hargreaves, B. A., Lenchik, L., Boutin, R., Chaudhari, A. S. 2023; 10 (2)

  Abstract

  We systematically evaluate the training methodology and efficacy of two inpainting-based pretext tasks of context prediction and context restoration for medical image segmentation using self-supervised learning (SSL). Multiple versions of self-supervised U-Net models were trained to segment MRI and CT datasets, each using a different combination of design choices and pretext tasks to determine the effect of these design choices on segmentation performance. The optimal design choices were used to train SSL models that were then compared with baseline supervised models for computing clinically-relevant metrics in label-limited scenarios. We observed that SSL pretraining with context restoration using 32 × 32 patches and Poission-disc sampling, transferring only the pretrained encoder weights, and fine-tuning immediately with an initial learning rate of 1 × 10-3 provided the most benefit over supervised learning for MRI and CT tissue segmentation accuracy (p < 0.001). For both datasets and most label-limited scenarios, scaling the size of unlabeled pretraining data resulted in improved segmentation performance. SSL models pretrained with this amount of data outperformed baseline supervised models in the computation of clinically-relevant metrics, especially when the performance of supervised learning was low. Our results demonstrate that SSL pretraining using inpainting-based pretext tasks can help increase the robustness of models in label-limited scenarios and reduce worst-case errors that occur with supervised learning.

  View details for DOI 10.3390/bioengineering10020207

  View details for PubMedID 36829701

• Ageism in Society and Its Health Impact. AJR. American journal of roentgenology Lenchik, L., Steinbach, L., Boutin, R. D. 2023

  Abstract

  Ageism is an increasingly recognized form of cognitive bias involving stereotypes, prejudice, and discrimination directed toward people based on their age. Age-based bias influences how medicine is practiced and can result in profoundly negative but avoidable health outcomes. Awareness and education regarding ageism and its manifestations can improve the ability to identify and mitigate ageism. As this Viewpoint describes, radiologists are well situated to be part of the solution in addressing ageism.

  View details for DOI 10.2214/AJR.22.28748

  View details for PubMedID 36722760

• Imaging of Sarcopenia. Radiologic clinics of North America Boutin, R. D., Houston, D. K., Chaudhari, A. S., Willis, M. H., Fausett, C. L., Lenchik, L. 2022; 60 (4): 575-582

  Abstract

  Sarcopenia is currently underdiagnosed and undertreated, but this is expected to change because sarcopenia is now recognized with a specific diagnosis code that can be used for billing in some countries, as well as an expanding body of research on prevention, diagnosis, and management. This article focuses on practical issues of increasing interest by highlighting 3 hot topics fundamental to understanding sarcopenia in older adults: definitions and terminology, current diagnostic imaging techniques, and the emerging role of opportunistic computed tomography.

  View details for DOI 10.1016/j.rcl.2022.03.001

  View details for PubMedID 35672090

• A randomized phase II study of gemcitabine and nab-paclitaxel compared with 5-fluorouracil, leucovorin, and liposomal irinotecan in older patients with treatmentnaive metastatic pancreatic cancer (GIANT): ECOG-ACRIN EA2186-Trials in progress Dotan, E., Catalano, P. J., Lenchik, L., Boutin, R., Yao, X., Beg, S., Vijayvergia, N., Gatsonis, C., Zhen, D., Li, D., Wagner, L. I., Simon, M. A., Wong, T. Z., O'Dwyer, P. J. LIPPINCOTT WILLIAMS & WILKINS. 2022

  View details for Web of Science ID 000863680304938

• Sarcopenia in rheumatic disorders: what the radiologist and rheumatologist should know. Skeletal radiology Manzano, W., Lenchik, L., Chaudhari, A. S., Yao, L., Gupta, S., Boutin, R. D. 2021

  Abstract

  Sarcopenia is defined as the loss of muscle mass, strength, and function. Increasing evidence shows that sarcopenia is common in patients with rheumatic disorders. Although sarcopenia can be diagnosed using bioelectrical impedance analysis or DXA, increasingly it is diagnosed using CT, MRI, and ultrasound. In rheumatic patients, CT and MRI allow "opportunistic" measurement of body composition, including surrogate markers of sarcopenia, from studies obtained during routine patient care. Recognition of sarcopenia is important in rheumatic patients because sarcopenia can be associated with disease progression and poor outcomes. This article reviews how opportunistic evaluation of sarcopenia in rheumatic patients can be accomplished and potentially contribute to improved patient care.

  View details for DOI 10.1007/s00256-021-03863-z

  View details for PubMedID 34268590

• Body composition measurements and overall survival in patients with resectable pancreatic adenocarcinoma receiving neoadjuvant chemotherapy: Analysis from SWOG S1505. Sohal, D., Duong, M. T., Boutin, R., Lenchik, L., Kim, J., Gandhi, N., Beg, M., Wang-Gillam, A., Wade, J., Guthrie, K. A., Chiorean, E., Ahmad, S. A., Lowy, A. M., Hochster, H. S., Philip, P., Chang, V. LIPPINCOTT WILLIAMS & WILKINS. 2021

  View details for DOI 10.1200/JCO.2021.39.15_suppl.4131

  View details for Web of Science ID 000708120602231

• Reply to "Sarcopenia and Osteoporosis: A Practical Approach to Obtaining Valuable Information With CT". AJR. American journal of roentgenology Boutin, R. D., Lenchik, L. n. 2021: W1

  View details for DOI 10.2214/AJR.20.25316

  View details for PubMedID 33760652

• Diagnosing sarcopenia at the point of imaging care: analysis of clinical, functional, and opportunistic CT metrics. Skeletal radiology Yao, L., Petrosyan, A., Fuangfa, P., Lenchik, L., Boutin, R. D. 2020

  Abstract

  OBJECTIVE: To determine the relationship between CT-derived muscle metrics and standardized metrics of sarcopenia in patients undergoing routine CT imaging.MATERIALS AND METHODS: Data collected in 443 consecutive patients included body CT, grip strength, usual gait speed, and responses to SARC-F and FRAIL scale questionnaires. Functional and clinical metrics of sarcopenia were acquired at the time of CT. Metrics were analyzed using the diagnostic framework of the European Working Group on Sarcopenia in Older People (EWGSOP2). The skeletal muscle index (SMI) and skeletal muscle density (SMD) were measured at the T12 and L3 levels. Statistical methods include linear prediction models and ROC analysis.RESULTS: T12-SMD and L3-SMD in women and T12-SMD and L3-SMI in men show weak but significant (p<0.05) predictive value for gait speed, after adjusting for subject age and body mass index. The prevalence of abnormal CT SMI at T12 and L3 was 29% and 71%, respectively, corresponding to prevalences of confirmed sarcopenia by EWGSOP2 of 10% and 15%, respectively. The agreement of abnormal SARC-F and FRAIL scale screening and EWGSOP2 confirmed sarcopenia was slight to fair (kappa: 0.20-0.28). CT cutpoints, based on EWGSOP2 criteria for abnormal grip strength or gait speed, are generally lower than cutpoints based on normative population data.CONCLUSION: Collection of clinical and functional sarcopenia information at the point of imaging care can be accomplished quickly and safely. CT-derived muscle metrics show convergent validity with gait speed. Only a minority of subjects with low CT metrics have confirmed sarcopenia by EWGSOP2 definition.

  View details for DOI 10.1007/s00256-020-03576-9

  View details for PubMedID 32892227

• Computed Tomography (CT) Measurements of Sarcopenia Predict Length of Stay in Older Burn Patients. Journal of burn care & research : official publication of the American Burn Association Romanowski, K. S., Fuanga, P., Siddiqui, S., Lenchik, L., Palmieri, T. L., Boutin, R. D. 2020

  Abstract

  INTRODUCTION: Sarcopenia and frailty are associated with aging. In older burn patients, frailty has been associated with mortality and discharge disposition, but sarcopenia has not been examined. This study aims to investigate the relationship between frailty and CT-derived sarcopenia with length of stay and mortality in older burn patients.METHODS: Burn patients ≥60 years old admitted between 2008-2017 who had chest or abdomen CT scans within one week of admission were evaluated. Frailty was assessed using the Canadian Study of Health and Aging Clinical Frailty Scale (CFS). Sarcopenia was assessed on CT exams by measuring skeletal muscle index (SMI) of paraspinal muscles at T12 and all skeletal muscles at L3. The relationship between frailty scores and SMI with length of stay (LOS) and mortality was determined using logistic regression.RESULTS: 83 patients (59 men; mean age 70.2±8.5 years) had chest (n=50) or abdomen (n=60) CT scans. Mean TBSA = 14.3±14.0%, LOS = 25.8±21.3 days, CFS = 4.36±0.99. Sixteen patients (19.3%) died while in the hospital. CT-derived measurement of SMI at T12 was significantly associated with LOS (p&0.05), but not with mortality (p=0.561). CT-derived metrics at L3 were not significantly associated with outcomes. CFS was not associated with LOS (p = 0.836) or mortality (p=0.554).CONCLUSIONS: In older burn patients, low SMI of the paraspinal muscles at T12 was associated with longer LOS.

  View details for DOI 10.1093/jbcr/iraa149

  View details for PubMedID 32841333

• Association of adipose tissue and skeletal muscle metrics with overall survival and postoperative complications in soft tissue sarcoma patients: an opportunistic study using computed tomography. Quantitative imaging in medicine and surgery Boutin, R. D., Katz, J. R., Chaudhari, A. J., Yabes, J. G., Hirschbein, J. S., Nakache, Y. P., Seibert, J. A., Lamba, R., Fananapazir, G., Canter, R. J., Lenchik, L. 2020; 10 (8): 1580-1589

  Abstract

  To determine the relationship between adipose tissue and skeletal muscle measurements on computed tomography (CT) and overall survival and major postoperative complications in patients with soft-tissue sarcoma (STS).The retrospective study included 137 STS patients (75 men, 62 women; mean age, 53 years, SD 17.7; mean BMI, 28.5, SD 6.6) who had abdominal CT exams. On a single CT image, at the L4 pedicle level, measurements of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area and attenuation were obtained using clinical PACS and specialized segmentation software. Clinical information was recorded, including STS characteristics (size, depth, grade, stage, and site), overall survival, and postoperative complications. The relationships between CT metrics and survival were analyzed using Cox proportional hazard models and those between CT metrics and postoperative complications using logistic regression models.There were 33 deaths and 41 major postoperative complications. Measured on clinical PACS, the psoas area (P=0.003), psoas index (P=0.006), psoas attenuation (P=0.011), and total muscle attenuation (P=0.023) were associated with overall survival. Using specialized software, psoas attenuation was also associated with overall survival (P=0.018). Adipose tissue metrics were not associated with survival or postoperative complications.In STS patients, CT-derived muscle size and attenuation are associated with overall survival. These prognostic biomarkers can be obtained using specialized segmentation software or routine clinical PACS.

  View details for DOI 10.21037/qims.2020.02.09

  View details for PubMedID 32742953

  View details for PubMedCentralID PMC7378098

• Value-Added Opportunistic CT: Insights Into Osteoporosis and Sarcopenia. AJR. American journal of roentgenology Boutin, R. D., Lenchik, L. 2020: 1–13

  Abstract

  OBJECTIVE. The purpose of this article is to review the emerging field of opportunistic CT, which can be used to screen patients for osteoporosis and sarcopenia. CONCLUSION. Although body composition measurements are not routinely obtained using CT, quantitative assessment of bone and muscle biomarkers on CT can add value to patient care. Automated bone and muscle measurements promise to transform the everyday practice of radiology without resulting in additional cost or radiation exposure for patients.

  View details for DOI 10.2214/AJR.20.22874

  View details for PubMedID 32755187

• Marrow uptake on FDG PET/CT is associated with progression from smoldering to symptomatic multiple myeloma. Skeletal radiology Amini, B., Nakache, Y. N., Nardo, L., Manasanch, E. E., Sun, J., Lenchik, L., Boutin, R. D. 2020

  Abstract

  OBJECTIVE: To determine association of body composition measurements on CT and PET with progression of smoldering myeloma to multiple myeloma.METHODS: A retrospective cohort study in 65 patients with smoldering myeloma and PET/CT at diagnosis was performed at a tertiary cancer center. Subjects were between 38 and 87years of age (mean 64) and included 37 males. Primary outcome was progression-free survival as a function of bone, fat, and muscle metrics on CT and PET (measured at the level of L4 pedicles) and clinical confounders. CT metrics included attenuation of L4 and retroperitoneal fat and various indices derived from the psoas muscle. PET measures included SUVmax and SUVmean of L4, retroperitoneal fat, and psoas. Cox proportional hazards modeling was performed with entry and retention criteria of p<0.1 and p<0.05, respectively.RESULTS: SUVmax and SUVmean were associated for each compartment (R2=0.78-0.84), and SUVmean (SUV) was used for subsequent analyses. SUV of the L4 vertebral body was associated with attenuation of the L4 vertebral body (p=0.0032). There was no association between SUV and CT for muscle and fat compartments. In the subset of patients with bone marrow biopsy results (n=43), there was no association between SUV of L4 and plasma cell concentration on core biopsy or flow cytometry (p=0.089 and 0.072, respectively). The final Cox model showed association with albumin (HR 0.29, 95%CI 0.088-0.93, p=0.038), M protein (HR 1.31, 95%CI 1.021-1.68, p=0.034), and SUV of L4 (HR 1.99, 95%CI 1.037-3.82, p=0.039).CONCLUSION: SUV of L4 is a prognostic indicator in patients with smoldering myeloma.

  View details for DOI 10.1007/s00256-020-03529-2

  View details for PubMedID 32621061

• Accurate prediction of lumbar microdecompression level with an automated MRI grading system. Skeletal radiology Roller, B. L., Boutin, R. D., O'Gara, T. J., Knio, Z. O., Jamaludin, A., Tan, J., Lenchik, L. 2020

  Abstract

  OBJECTIVE: Lumbar spine MRI interpretations have high variability reducing utility for surgical planning. This study evaluated a convolutional neural network (CNN) framework that generates automated MRI grading for its ability to predict the level that was surgically decompressed.MATERIALS AND METHODS: Patients who had single-level decompression were retrospectively evaluated. Sagittal T2 images were processed by a CNN (SpineNet), which provided grading for the following: central canal stenosis, disc narrowing, disc degeneration, spondylolisthesis, upper/lower endplate morphologic changes, and upper/lower marrow changes. The grades were used to calculate an aggregate score. The variables and the aggregate score were analyzed for their ability to predict the surgical level. For each surgical level subgroup, the surgical level aggregate scores were compared with the non-surgical levels.RESULTS: A total of 141 patients met the inclusion criteria (82 women, 59 men; mean age 64years; age range 28-89years). SpineNet did not identify central canal stenosis in 32 patients. Of the remaining 109, 96 (88%) patients had a decompression at the level of greatest stenosis. The higher stenotic grade was present only at the surgical level in 82/96 (85%) patients. The level with the highest aggregate score matched the surgical level in 103/141 (73%) patients and was unique to the surgical level in 91/103 (88%) patients. Overall, the highest aggregate score identified the surgical level in 91/141 (65%) patients. The aggregate MRI score mean was significantly higher for the L3-S1 surgical levels.CONCLUSION: A previously developed CNN framework accurately predicts the level of microdecompression for degenerative spinal stenosis in most patients.

  View details for DOI 10.1007/s00256-020-03505-w

  View details for PubMedID 32607805

• Opportunistic muscle measurements on staging chest CT for extremity and truncal soft tissue sarcoma are associated with survival. Journal of surgical oncology Phan, E. N., Thorpe, S. W., Wong, F. S., Saiz, A. M., Taylor, S. L., Canter, R. J., Lenchik, L., Randall, R. L., Boutin, R. D. 2020

  Abstract

  BACKGROUND AND OBJECTIVES: Computed tomography (CT) measurements of sarcopenia have been proposed as biomarkers associated with outcomes in various cancers and have typically been evaluated at the L3 vertebral level. However, staging imaging for patients with extremity and truncal soft tissue sarcoma (STS) often only includes chest CT imaging which precludes evaluation at L3. Therefore, we sought to evaluate muscle metrics at T12 on standard staging chest CT scans and evaluate for correlation with overall and event-free survival in patients with STS.METHODS: CT chest imaging for 89 patients with intermediate and high-grade STS (53 male, 36 female; 58.5±19.0 years old, follow-up 37.4±27.1 months) was reviewed on PACS at T12 for skeletal muscle density (SMD) and skeletal muscle index (SMI).RESULTS: Overall survival increased with increased SMD on univariate (hazard ratio [HR]=0.61 [0.43, 0.86]) and age-adjusted analysis (HR=0.65 [0.42, 0.89]. Event-free survival also increased with increased SMD in univariate analyses (HR=0.68 [0.49, 0.95]) but did not maintain significance after adjusting for age (HR=0.68 [0.43, 1.07]). SMI was not a predictor of overall or event-free survival.CONCLUSIONS: Higher SMD measured on routinely obtained staging chest CTs in STS patients is associated with improved survival.

  View details for DOI 10.1002/jso.26077

  View details for PubMedID 32613648

• Automated Muscle Measurement on Chest Computed Tomography (CT) Predicts All-cause Mortality in Older Adults from the National Lung Screening Trial. The journals of gerontology. Series A, Biological sciences and medical sciences Lenchik, L., Barnard, R., Boutin, R. D., Kritchevsky, S. B., Chen, H., Tan, J., Cawthon, P. M., Weaver, A. A., Hsu, F. 2020

  Abstract

  BACKGROUND: Muscle metrics derived from CT are associated with adverse health events in older persons, but obtaining these metrics using current methods is not practical for large datasets. We developed a fully-automated method for muscle measurement on CT images. This study aimed to determine the relationship between muscle measurements on CT with survival in a large multicenter trial of older adults.METHODS: The relationship between baseline paraspinous skeletal muscle area (SMA) and skeletal muscle density (SMD) and survival over 6 years was determined in 6803 men and 4558 women (baseline age: 60-69 years) in the National Lung Screening Trial (NLST). The automated machine learning pipeline selected appropriate CT series, chose a single image at T12, and segmented left paraspinous muscle, recording cross-sectional area and density. Associations between SMA and SMD with all-cause mortality were determined using sex-stratified Cox proportional hazards models, adjusted for age, race, height, weight, pack-years of smoking, and presence of diabetes, chronic lung disease, cardiovascular disease, and cancer at enrollment.RESULTS: After a mean 6.44 ± 1.06 years of follow-up, 635 (9.33%) men and 265 (5.81%) women died. In men, higher SMA and SMD were associated with a lower risk of all-cause mortality, in fully adjusted models. A one-unit standard deviation increase was associated with a hazard ratio (HR)=0.85 (95%CI=0.79,0.91;p<0.001) for SMA and HR=0.91 (95%CI=0.84,0.98;p=0.012) for SMD. In women, the associations did not reach significance.CONCLUSION: Higher paraspinous SMA and SMD, automatically derived from CT exams, were associated with better survival in a large multicenter cohort of community-dwelling older men.

  View details for DOI 10.1093/gerona/glaa141

  View details for PubMedID 32504466

• Association of adipose tissue and skeletal muscle metrics with overall survival and postoperative complications in soft tissue sarcoma patients: An opportunistic study using computer tomography of the abdomen Quant Imaging Med Surg Boutin, R. D., Katz, J., Chaudhari, A., et al 2020: [Epub ahead of print]

  View details for DOI 10.21037/qims.2020.02.09

• CT Phantom Evaluation of 67,392 ACR Accreditation Examinations: Implications for Opportunistic Screening of Osteoporosis Using CT. AJR. American journal of roentgenology Boutin, R. D., Hernandez, A. M., Lenchik, L. n., Seibert, J. A., Gress, D. A., Boone, J. M. 2020

  Abstract

  Please see the Author Video associated with this article. OBJECTIVE. To investigate if there is a systematic bias in CT number (Hounsfield unit) measurements between scanners made by four major CT manufacturers. METHODS. CT number accuracy data acquired using the American College of Radiology (ACR) accreditation phantom were evaluated in a blinded fashion for four CT manufacturers (A: n=8,500; B: n=18,575; C: n=8,278, D: n=32,039). The CT number of water, acrylic (surrogate for trabecular bone), and teflon (surrogate for cortical bone) for an adult abdomen CT technique (120 kV, 240 mA, 50-cm FOV, standard reconstruction algorithm) was used in the analysis. Differences in HU values across all manufacturers were assessed using the Kruskal-Wallis test followed by a post-hoc test for pairwise comparisons. RESULTS. The mean CT number of water ranged from -0.3 to 2.7 HU, with highly significant differences between all manufacturers (p < 0.001). For the trabecular bone surrogate, differences in CT numbers across all manufacturers were also highly significant (p < 0.001), with mean values [standard deviation, SD] of 120.9 [3.5], 124.6 [3.3], 126.9 [4.4], and 123.9 [3.4] for manufacturers A, B, C, and D, respectively. For the cortical bone surrogate, differences in CT numbers across all manufacturers were also highly significant (p < 0.001), with mean values [SD] of 939.0 [14.2], 874.3 [13.3], 897.6 [11.3], and 912.7 [13.4] for manufacturers A, B, C, and D, respectively. CONCLUSION. CT number measurements between manufacturers have a systematic offset when compared to each other. Knowledge of these offsets is useful for optimizing the accuracy of opportunistic diagnosis of osteoporosis.

  View details for DOI 10.2214/AJR.20.22943

  View details for PubMedID 32755177

• Opportunistic body composition evaluation in patients with esophageal adenocarcinoma: association of survival with 18F-FDG PET/CT muscle metrics. Annals of nuclear medicine Zhou, C., Foster, B., Hagge, R., Foster, C., Lenchik, L., Chaudhari, A. J., Boutin, R. D. 2019

  Abstract

  OBJECTIVE: 18F-FDG PET is widely used to accurately stage numerous types of cancers. Although 18F-FDG PET/CT features of tumors aid in predicting patient prognosis, there is increasing interest in mining additional quantitative body composition data that could improve the prognostic power of 18F-FDG PET/CT, without additional examination costs or radiation exposure. The aim of this study was to determine the association between overall survival and body composition metrics derived from routine clinical 18F-FDG PET/CT examinations.METHODS: Patients who received baseline 18F-FDG PET/CT imaging during workup for newly diagnosed esophageal adenocarcinoma (EAC) were included. From these studies, psoas cross-sectional area (CSA), muscle attenuation (MA), SUVmean, and SUVmax were obtained. Correlation with overall survival was assessed using a Cox Proportional Hazards model, controlling for age, body mass index, 18F-FDG dose, glucose level, diabetes status, in-hospital status, and tumor stage.RESULTS: Among the 59 patients studied, psoas MA and SUVmax were found to be significant predictors of survival (HR 0.94, 95% CI 0.88-0.99, p=0.04, and HR 0.37, 95% CI 0.14-0.97, p=0.04, respectively) and remained independent predictors. Psoas CSA and SUVmean did not significantly influence survival outcomes.CONCLUSIONS: Characterization of psoas muscles as a surrogate marker for sarcopenia on baseline 18F-FDG PET/CT imaging is relatively easily obtained and may offer additional prognostic value in patients with EAC.

  View details for DOI 10.1007/s12149-019-01429-7

  View details for PubMedID 31823231

• The Official Positions of the International Society for Clinical Densitometry: Cross Calibration, Least Significant Change, and Quality Assurance in Multiple Dual-Energy X-Ray Absorptiometry Scanner Environments. Journal of clinical densitometry : the official journal of the International Society for Clinical Densitometry Jankowski, L. G., Warner, S. n., Gaither, K. n., Lenchik, L. n., Fan, B. n., Lu, Y. n., Shepherd, J. n. 2019

  Abstract

  In preparation for the International Society for Clinical Densitometry Position Development Conference (PDC) 2019 in Kuala Lumpur, Malaysia, a cross-calibration and precision task force was assembled and tasked to review the literature, summarize the findings, and generate positions to answer 4 related questions provided by the PDC Steering Committee, which expand upon the current ISCD official positions on these subjects. (1) How should a provider with multiple dual-energy X-ray absorptiometry (DXA) scanners of the same make and model calculate least significant change (LSC)? (2) How should a provider with multiple DXA systems with the same manufacturer but different models calculate LSC? (3) How should a provider with multiple DXA systems from different manufacturers and models calculate LSC? (4) Are there specific phantom procedures that one can use to provide trustworthy in vitro cross calibration for same models, different models, and different makes? Based on task force deliberations and the resulting systematic literature reviews, 3 new positions were developed to address these more complex scenarios not addressed by current official positions on single scanner cross calibration and LSC. These new positions provide appropriate guidance to large multiple DXA scanner providers wishing to offer patients flexibility and convenience, and clearly define good clinical practice requirements to that end.

  View details for DOI 10.1016/j.jocd.2019.09.001

  View details for PubMedID 31558404