LAUSR

Abstract The aim of the study was to introduce our in-house software to measure the muscle and adipose area on axial computed tomography (CT) scans and to compare with various quantification methods. Our institutional review board approved this retrospective study and informed consent was waived. We developed in-house software to identify body composition analysis on CT scan, which semiautomatically operates 3 image processing steps. Abdominal images were obtained using multidetector row CT (MDCT). Two radiologists analyzed the same cross-sectional areas of subcutaneous fat, muscle, and visceral fat using the following techniques: manual measurements, Aquarius, ImageJ, and our newly developed software. We calculated an intraclass correlation coefficient (ICC) for comparison of muscle and fat areas quantified by various measurement methods using a 2-way random model. Interobserver agreement between the radiologists was also evaluated. Agreements in the measurement of subcutaneous fat and muscle areas were excellent among the methods (ICC = 0.962 and 0.897, respectively), and that of the visceral fat area was good (ICC = 0.822). In the subgroup analysis, ICC of the visceral fat area in the female group and in subjects with ascites was slightly lower than the other group (ICC = 0.742 and 0.787, respectively). The correlation coefficients between our software and other methods were relatively high (r = 0.854–0.996). Additionally, ICCs between both observers of our program for quantification of subcutaneous fat, muscle, and visceral fat areas were 0.999, 0.980, and 0.999, respectively. In conclusion, our method showed be reliable in quantifying muscle and adipose tissue using cross-sectional areas of MDCT with high reproducibility.