The Effect of Falsely Highlighted Intestinal Intraluminal Areas and the Fat in Paraspinal Muscles on Abdominal Adipose Tissue Measurements Using Computed Tomography

Objective: The measurement of abdominal fat using computed tomography (CT) is a reliable method for evaluating metabolic disorders. However, some limitations exist with the current CT measurement methods. One of them is falsely highlighted intestinal intraluminal areas and the other one is fat in paraspinal muscles. We aimed to investigate the effects of highlighted intestinal intraluminal areas and fat in paraspinal muscles on the measured values of abdominal fat. Material and Methods: Measurements were performed on 246 abdominal CT scans of 129 patients using dedicated quantitative CT software. Visceral and subcutaneous fats were measured at the level of L1-L2 disc space using two different methods. Method 1 included the highlighted intestinal intraluminal areas and fat in paraspinal muscles for measurements, whereas method 2 excluded them. The values measured using two methods were compared for a statistically significant difference. In addition, the correlation between anthropometric data and subcutaneous adipose tissue measurement methods was analyzed. Results: The mean age of patients was 53 years, and the mean body mass index was 29.73 kg/m2. The waist circumference data were available of 91 patients, and the mean waist circumference was 94 cm. The Wilcoxon signed-rank sum test showed a statistically significant difference between methods 1 and 2 (p<0.0001). Although the measurements performed using methods 1 and 2 were strongly correlated (r>0.9), the Passing-Bablok regression analysis indicated a systematic and proportional error between measurements. Conclusion: Falsely highlighted intestinal intraluminal areas should be excluded for accurate visceral adipose tissue measurements, and the fat in paraspinal muscles affects subcutaneous fat measurement results.