Chest computed tomography is a valid measure of body composition in individuals with advanced lung disease

Abstract

There is growing interest in evaluating body composition using routine clinical computed tomography (CT) scans; however, the validity of this technique in lung transplant patients has not been described. The study objectives were to determine the reliability of measuring fat compartments from thoracic CT and evaluate the validity of muscle and fat cross‐sectional area (CSA) from thoracic CT by comparing to bioelectrical impedance analysis (BIA). Thoracic CT scans from lung transplant assessments were obtained for analysis. Total thoracic muscle CSA, pectoral muscle CSA, subcutaneous adipose tissue (SAT), and mediastinal adipose tissue (MAT) were manually segmented by two independent raters. Reliability was analysed using intra‐class correlation coefficient (ICC). Correlations were determined between CT measures with fat‐free mass index (FFMI), body fat mass index (BFMI) and per cent body fat (%BF) from BIA; and anthropometrics [body mass index (BMI) and waist circumference (WC)]. High inter‐ and intra‐rater reliability were found for SAT and MAT (ICCs = 0.99). Pectoral and total muscle CSA were correlated with FFMI (r = .41, p = .003 and r = .57, p < .001, respectively). SAT was associated with whole‐body fat from BIA and with BMI and WC (r = .61 to .80, p < .001). MAT was associated with BMI (r = .58, p < .001) and WC (r = .61, p < .001). This study supports the reliability and validity of using thoracic CT to measure muscle and fat. Future studies are needed to investigate whether these CT‐based measures are predictive of clinical and post‐transplant outcomes in advanced lung disease.

Body composition on low dose chest CT is a significant predictor of poor clinical outcome in COVID-19 disease - A multicenter feasibility study

“…Since this area was not available on the LDCT examinations of the thorax, we had to modify our approach to the height of the 12th thoracic vertebrae. However, there is also evidence - admittedly not so numerous - of good correlations between thoracic muscle areas and body composition [ 26 , 41 , 42 ]. Furthermore, no additional measurements were performed using other methods, such as bioelectrical impedance analysis or dual X-ray absorptiometry.…”

Clinical outcomes associated with computed tomography‐based body composition measures in lung transplantation: a systematic review

“…Presently, it is not possible to make a recommendation as to the optimal CT measurement technique to apply for evaluation of low muscle mass and adiposity. There remains lack of methodological standardization across CT body composition assessments with most studies using individual chest or abdominal axial slices in LTx candidates at various anatomic locations, even though these individual axial slices have shown strong correlation with CT thoracic‐abdominal muscle and adiposity volumes [68,69], and with whole body composition measures (DXA, BIA) [70]. The CT body composition assessment seems to be driven by center experience and the availability of abdominal or chest scans given thoracic scans are more likely to be the standard of care at most LTx centers [18–22].…”

“…Furthermore, it is important to highlight that CT body composition measures are surrogate markers of whole body composition shown to be stronger prognostic markers than BMI [14,23], which is known for its poor discriminatory ability for muscle mass or adiposity measures. However, it is important to highlight that CT body composition measures may be relatively preserved compared to the dynamic nature of lower extremity limb muscle size or function [46,70] and may have a differential effect on post‐transplant outcomes. Future study exploring associations of body composition with functional measures, plasma biomarkers, and rehabilitation response may provider greater insight into the clinical utility of these body composition measures in lung transplantation.…”

Adipose tissue biomarkers and type 2 diabetes incidence in normoglycemic participants in the MESArthritis Ancillary Study: A cohort study

“…Imaging-derived adipose tissue biomarkers have the potential to provide a better characterization of ectopic adipose depots distribution [12]. In addition to dedicated imaging techniques for evaluating body composition and adipose depots distribution (e.g., dual-energy Xray absorptiometry or bioelectrical impedance), chest computed tomography (CT) exams that are commonly performed in the routine clinical practice for cardiopulmonary indications (e.g., coronary calcium scoring [13] or lung cancer screening [14]) retain data on adipose depots distribution, and there is an opportunity to extract biomarkers on the distribution of ectopic adipose depots from these CT exams, at zero additional cost or radiation exposure [15][16][17].…”