MRI-Based Body Composition Analysis

Body composition was analysed using MRI. The participants were scanned in a Philips Ingenia 3 T MRI scanner (Philips Healthcare, the Netherlands) using a 6-minute dual-echo Dixon protocol, providing water and fat separated volumetric data covering a region from the neck to the knees. Body composition profiling39 (link) was performed using AMRA^® Researcher (AMRA Medical AB, Linköping, Sweden). The analysis consisted of the following steps: 1) automatic image calibration, 2) automatic labelling and registration of fat and muscle regions to the acquired image volumes, 3) quality control of anatomical regions and MR-data performed by trained analysis engineers at AMRA Medical, and 4) quantification of fat and muscle volumes based on the calibrated images.40–43 (link) The measurements included the volumes of VAT, “abdominal subcutaneous adipose tissue” (ASAT), and the sum of these, that is, the “total abdominal adipose tissue” (TAAT). The volumetric adipose tissue measurements were normalised for height (ASATi, VATi and TAATi) and expressed as L/m². The “total thigh fat-free muscle volume” (FFMV) and mean anterior thigh MFI were also measured, and the assessments of those measurements are described in the following sections.