Diagnosing sarcopenia at the point of imaging care: analysis of clinical, functional, and opportunistic CT metrics

Defining Reference Values for Skeletal Muscle Metrics on Abdominal CT Using Data From Healthy Young Adult Populations: A Systematic Review and Meta-Analysis

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.

Sarcopenia Diagnosis Trends and Opportunistic Use of Abdominal CT Among Medicare Beneficiaries

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

The risk factors for low back pain following oblique lateral interbody fusion: focus on sarcopenia

BACKGROUND

Sarcopenia had been identified as a factor influencing the postoperative outcomes of lumbar surgery. The effect of sarcopenia on the surgical outcomes in patients who underwent oblique lateral interbody fusion (OLIF) had not yet been examined.

OBJECTIVE

The aim of our study was to investigate the association between sarcopenia and postoperative low back pain (LBP) in patients following OLIF and provide recommendations for surgical strategy.

METHODS

116 patients who underwent OLIF were retrospectively reviewed. Patients were classified into sarcopenia group (Group SP) and non-sarcopenia group (Group NSP). According to whether instruments was performed, Group SP was further divided into OLIF stand-alone group (Group SP-SA) and OLIF with instruments group (Group SP-IN). The patient characteristics, surgical data and questionnaire scores were collected. Oswestry Disability Index (ODI) score was used to evaluate lumbar function and pain intensity. Multivariable logistic regression analysis was used to identify the risk factors for postoperative LBP.

RESULTS

There were 38 patients in Group SP and 78 patients in Group NSP. The incident rare of osteoporosis in Group SP was higher than that in Group NSP (P = 0.012). In Group SP, last follow-up intervertebral height (IH) was lower (P = 0.045) and incident rate of cage subsidence was higher ((P = 0.044). No significant difference (P = 0.229) showed in preoperative ODI scores, however, last follow-up ODI scores in Group SP was significantly higher (P = 0.017) than that in Group NSP. Multivariable logistic regression analysis showed that sarcopenia (P = 0.004), osteoporosis (P = 0.012) and cage subsidence (P = 0.002) were identified as risk factors for postoperative LBP. In Group SP-IN, last follow-up ODI score (P = 0.024) and incident rate of cage subsidence (P = 0.027) were significantly lower Compared to Group SP-SA.

CONCLUSIONS

LBP was a common complication following OLIF with the incidence rate of 18.1%. Sarcopenia, osteoporosis and cage subsidence were risk factors for LBP following OLIF. Instruments effectively reduced the incidence and degree of postoperative LBP in patients with sarcopenia following OLIF. Consequently, we suggest incorporating supplementary instruments for patients with sarcopenia in surgical strategy.

DXA-based appendicular composition measures in healthy aging Caucasian Greek women: a cross-sectional study

As the global population of older persons increases, age-related medical conditions will have a greater impact on public health. DXA-derived bone and soft tissue metrics are associated with adverse clinical events in aging persons. This study aims to investigate the regional body composition of the appendices by whole-body DXA scans, and the age-related relationships between measures of bone and soft tissue in healthy Caucasian females of a Greek origin residing in the Mediterranean area. Body composition of the legs and the arms was analyzed, and lean mass (LM) and fat mass (FM) metrics were calculated in 330 women aged 20-85 years, using DXA. Peak bone mineral density (BMD) of the legs and arms was achieved between ages 20-30 and 41-50 years, respectively. The overall BMD reduction with age was for the legs 43% and the arms 32.2% (p < 0.001). Peak %LM of the legs and the arms was achieved between ages 20-30. The overall reduction of %LM with age was for the legs 22.5% (p < 0.001) and arms 6.6% (p < 0.05). Peak %FM of the legs and arms was attained between ages 31-40 and 61-70, respectively. The overall %FM reduction with age was for the legs and arms 7.5% and 1.9% (p > 0.05). In appendicular sites, Greek women reach peak values of bone mass in the legs first, in early adulthood. Bone loss predominates in the legs as women age. Also, with advancing age Greek women show preferential significant decreases of %LM and %FM in the legs as opposed to the arms. Although variation in appendicular bone and soft tissue metrics is present, the implications of variable biological crosstalks among the tissue components as women age may ultimately lay the foundation for future clinical trials aimed at healthy aging.

Surface-Guided Crystallization of Xanthine Derivatives for Optical Metamaterial Applications

Numerous bio-organisms employ template-assisted crystallization of molecular solids to yield crystal morphologies with unique optical properties that are difficult to reproduce synthetically. Here, a facile procedure is presented to deposit bio-inspired birefringent crystals of xanthine derivatives on a template of single-crystal quartz. Crystalline sheets that are several millimeters in length, several hundred micrometers in width, and 300-600 nm thick, are obtained. The crystal sheets are characterized with a well-defined orientation both in and out of the substrate plane, giving rise to high optical anisotropy in the plane parallel to the quartz surface, with a refractive index difference Δn ≈ 0.25 and a refractive index along the slow axis of n ≈ 1.7. It is further shown that patterning of the crystalline stripes with a tailored periodic grating leads to a thin organic polarization-dependent diffractive meta-surface, opening the door to the fabrication of various optical devices from a platform of small-molecule based organic dielectric crystals.

Sarcopenia and frailty as predictors of surgical morbidity and oncologic outcomes in retroperitoneal sarcoma

BACKGROUND

Retroperitoneal sarcomas (RPS) are rare tumors for which surgical resection is the principal treatment. There is no established model to predict perioperative risks for RPS. We evaluated the association between preoperative sarcopenia, frailty, and hypoalbuminemia with surgical and oncological outcomes.

METHODS

We performed a prospective cohort analysis of 65 RPS patients who underwent surgical resection. Sarcopenia was defined as Total Psoas Area Index ≤ 1st quintile by sex. Frailty was estimated using the modified frailty index (mFI). Logistic regression models were used to assess predictors of 30-day postoperative morbidity. The Kaplan-Meier method with log-rank test was utilized to assess factors associated with overall (OS) and recurrence-free survival (RFS).

RESULT

Sarcopenia was associated with worse OS with a median of 54 compared with 158 months (p = 0.04), but no differences in RFS (p > 0.05). Hypoalbuminemia was associated with worse OS with a median of 72 compared with 158 months (p < 0.01). MFI scores were not associated with OS or RFS (p > 0.05). Sarcopenia, mFI, and hypoalbuminemia were not associated with postoperative morbidity (p > 0.05).

CONCLUSION

This study suggests that sarcopenia may be utilized as a measure of overall fitness, rather than a cancer-specific risk, and the mFI is a poor predictive measure of outcomes in RPS.

GI Symptoms in Pancreatic Cancer

This review will apply a multidisciplinary approach to GI symptoms with attention to symptom assessment (instruments and qualitative aspects), differential diagnosis, and recent findings relevant to management of symptoms and underlying diseases. We conclude that further development of supportive interventions for GI symptoms for both patient and caregivers has the potential to reduce distress from GI symptoms, and anticipate better symptom control with advances in scientific knowledge and improvement of the evidence base.

Effect of teach-back health education combined with structured psychological nursing on adverse emotion and patient cooperation during 99mTc-3PRGD2.SPECT/CT

BACKGROUND

^99mTc-3PRGD2.SPECT/CT is a commonly used examination method in nuclear medicine. However, patients receiving ^99mTc-3PRGD2.SPECT/CT have insufficient knowledge of this method and worry about the examination results.

AIM

To investigate the effect of teach-back health education combined with structured psychological nursing on adverse emotion and cooperation in patients undergoing ^99mTc-3PRGD2.SPECT/CT examination.

METHODS

Ninety patients undergoing ^99mTc-3PRGD2.SPECT/CT examinations were divided into a study group and a control group using a simple random number table, and 45 cases were allocated to each group. Routine nursing was provided to the control group, and teach-back health education combined with structured psychological nursing was provided to the study group on the basis of the control group. Heart rate, diastolic blood pressure, systolic blood pressure, self-rating depression scale (SDS), and self-rating anxiety scale (SAS) were assessed before and after the intervention, and examination cooperation and intervention satisfaction were assessed in the two groups before, during, and after the examination.

RESULTS

Before the examination, heart rate, diastolic blood pressure, and systolic blood pressure in the study group were not significantly different from the values of the control group (P > 0.05). The results of the study group before and after the examination were lower than those in the control group (P < 0.05). Before the intervention, SDS and SAS scores in the study group were not significantly different from those in the control group (P > 0.05). After the intervention, SDS and SAS scores in the study group were lower than those in the control group (P < 0.05). The degree of cooperation was higher in the study group than in the control group (P < 0.05). The satisfaction rate with the intervention was higher in the study group than in the control group (P < 0.05).

CONCLUSION

Teach-back health education combined with structured psychological nursing can help maintain the stability of blood pressure and heart rate, relieve negative emotions, and improve the satisfaction and cooperation of patients undergoing ^99mTc-3PRGD2.SPECT/CT examinations.

Imaging of Sarcopenia

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.

[Impact of sarcopenia on effectiveness of lumbar decompression surgery in patients with lumbar spinal stenosis]

OBJECTIVE

To investigate the impact of sarcopenia on effectiveness of lumbar decompression surgery in patients with lumbar spinal stenosis.

METHODS

The clinical data of 50 patients with lumbar spinal stenosis who met the selection criteria between August 2017 and December 2020 were retrospectively analyzed. According to the diagnostic criteria of the European Working Group on Sarcopenia in Older People (EWGSOP), based on the calculation of the skeletal muscle index (SMI) at the L ₃ level, SMI<45.4 cm ²/m ² (men) and SMI<34.4 cm ²/m ² (women) were used as the diagnostic threshold, the patients were divided into sarcopenia group (25 cases) and non-sarcopenia group (25 cases). There was no significant difference in gender, age, disease duration, level of lumbar spinal stenosis, surgical fusion level, and comorbidity between the two groups ( P>0.05); the body mass index in sarcopenia group was significantly lower than that in non-sarcopenia group ( t=-3.198, P=0.002). Clinical data of the two groups were recorded and compared, including operation time, intraoperative blood loss, postoperative drainage volume, hospitalization stay, and complications. The visual analogue scale (VAS) scores of low back pain and sciatica and Oswestry disability index (ODI) scores were recorded preoperatively and at last follow-up. The effectiveness was evaluated according to modified MacNab standard.

RESULTS

There was no significant difference between the two groups in terms of operation time, intraoperative blood loss, and postoperative drainage volume ( P>0.05). However, the hospitalization stay in sarcopenia group was significantly longer than that in non-sarcopenia group ( t=2.105, P=0.044). The patients were followed up 7-36 months (mean, 29.7 months). In sarcopenia group, 1 case of dural tear and cerebrospinal fluid leakage occurred during operation, as well as 1 case of internal fixator loosening during follow-up; 1 case of incision exudation and poor healing occurred in each of the two groups, and no adjacent segment degeneration and deep vein thrombosis of lower extremity occurred in the two groups during follow-up. There was no significant difference in the incidence of complications (12% vs. 4%) between the two groups ( χ ²=1.333, P=0.513). VAS scores in low back pain and sciatica as well as ODI scores in two groups significantly improved when compared with preoperative results at last follow-up ( P<0.05). The differences of VAS scores in low back pain and ODI scores before and after operation in sarcopenia group were significantly lower than that in non-sarcopenia group ( P<0.05). However, there was no significant difference of that in VAS scores of sciatica between the two groups ( t=-1.494, P=0.144). According to the modified MacNab standard, the excellent and good rate of the sarcopenia group was 92%, and that of the non-sarcopenia group was 96%, showing no significant difference between the two groups ( χ ² =1.201, P=0.753).

CONCLUSION

Patients with sarcopenia and lumbar spinal stenosis may have longer postoperative recovery time, and the effectiveness is worse than that of non-sarcopenic patients. Therefore, for elderly patients with lumbar spine disease, it is suggested to improve preoperative assessment of sarcopenia, which can help to identify patients with sarcopenia at risk of poor surgical prognosis in advance, so as to provide rehabilitation guidance and nutritional intervention in the perioperative period.

Sarcopenia in rheumatic disorders: what the radiologist and rheumatologist should know

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.

Piloting a training program in computed tomography (CT) skeletal muscle assessment for Registered Dietitians

BACKGROUND

Consensus definitions for disease-associated malnutrition and sarcopenia include reduced skeletal muscle mass as a diagnostic criterion. There is a need to develop and validate techniques to assess skeletal muscle in clinical practice. Skeletal muscle mass can be precisely quantified from computed tomography (CT) images. This pilot study aimed to train Registered Dietitians (RD) to complete precise skeletal muscle measurements using CT.

METHODS

Purposive sampling identified RDs employed in clinical areas where CT scans are routinely performed. CT training included: 1) a 3-day training session focused on manual segmentation of skeletal muscle cross-sectional areas (cm² ) from abdominal CT images at the third lumber (L3) vertebra, using SliceOmatic® software, and 2) a precision assessment to quantify the intra- and inter-observer precision error of repeated skeletal muscle measurements (30 images in duplicate). Precision error is reported as the root mean standard deviation (cm² ) and % coefficient of variation (%CV), our primary performance indicator was defined as a precision error <2%.

RESULTS

Five RDs completed CT training. RDs were from three clinical areas (cancer care (N=1), surgery (N=2), and critical care (N=1). RDs precision error was low and below the minimal acceptable error of <2%; intra-observer error was ≤1.8 cm² (range 0.8 - 1.8 cm² ) or ≤1.5% (range 0.8 - 1.5%) and inter-observer error was 1.2 cm² or 1.1%.

CONCLUSION

RDs can be trained to perform precise CT skeletal muscle measurements. Increasing capacity to assess skeletal muscle is a first step toward developing this technique for use in clinical practice.

CLINICAL RELEVANCE STATEMENT

There is significant interest from both researchers and clinicians to undertake the measurement of skeletal muscle. Reduced skeletal muscle mass places individuals at risk of experiencing adverse outcomes and is a diagnostic criterion for disease-associated malnutrition and sarcopenia. In this study we piloted a training program in computed tomography (CT)-skeletal muscle assessments for RDs, and demonstrated after completion of the program RDs were able to perform CT skeletal muscle measurements with high precision. The addition of new tools to the comprehensive nutrition assessment tool box may benefit clinical practice in multiple ways including improved identification of patients with reduced skeletal muscle mass, individualization of interventions, and monitoring effectiveness of interventions over time. Other clinicians may also benefit from knowing about their patients' skeletal muscle mass to help identify risk and make treatment decisions. This article is protected by copyright. All rights reserved.

Percentile-based averaging and skeletal muscle gauge improve body composition analysis: validation at multiple vertebral levels

BACKGROUND

Skeletal muscle metrics on computed tomography (CT) correlate with clinical and patient-reported outcomes. We hypothesize that aggregating skeletal muscle measurements from multiple vertebral levels and skeletal muscle gauge (SMG) better predict outcomes than skeletal muscle radioattenuation (SMRA) or -index (SMI) at a single vertebral level.

METHODS

We performed a secondary analysis of prospectively collected clinical (overall survival, hospital readmission, time to unplanned hospital readmission or death, and readmission or death within 90 days) and patient-reported outcomes (physical and psychological symptom burden captured as Edmonton Symptom Assessment Scale and Patient Health Questionnaire) of patients with advanced cancer who experienced an unplanned admission to Massachusetts General Hospital from 2014 to 2016. First, we assessed the correlation of skeletal muscle cross-sectional area, SMRA, SMI, and SMG at one or more of the following thoracic (T) or lumbar (L) vertebral levels: T5, T8, T10, and L3 on CT scans obtained ≤50 days before index assessment. Second, we aggregated measurements across all available vertebral levels using percentile-based averaging (PBA) to create the average percentile. Third, we constructed one regression model adjusted for age, sex, sociodemographic factors, cancer type, body mass index, and intravenous contrast for each combination of (i) vertebral level and average percentile, (ii) muscle metrics (SMRA, SMI, & SMG), and (iii) clinical and patient-reported outcomes. Fourth, we compared the performance of vertebral levels and muscle metrics by ranking otherwise identical models by concordance statistic, number of included patients, coefficient of determination, and significance of muscle metric.

RESULTS

We included 846 patients (mean age: 63.5 ± 12.9 years, 50.5% males) with advanced cancer [predominantly gastrointestinal (32.9%) or lung (18.9%)]. The correlation of muscle measurements between vertebral levels ranged from 0.71 to 0.84 for SMRA and 0.67 to 0.81 for SMI. The correlation of individual levels with the average percentile was 0.90-0.93 for SMRA and 0.86-0.92 for SMI. The intrapatient correlation of SMRA with SMI was 0.21-0.40. PBA allowed for inclusion of 8-47% more patients than any single-level analysis. PBA outperformed single-level analyses across all comparisons with average ranks 2.6, 2.9, and 1.6 for concordance statistic, coefficient of determination, and significance (range 1-5, μ = 3), respectively. On average, SMG outperformed SMRA and SMI across outcomes and vertebral levels: the average rank of SMG was 1.4, 1.4, and 1.4 for concordance statistic, coefficient of determination, and significance (range 1-3, μ = 2), respectively.

CONCLUSIONS

Multivertebral level skeletal muscle analyses using PBA and SMG independently and additively outperform analyses using individual levels and SMRA or SMI.