AUTOMATED IDENTIFICATION OF ADIPOSE TISSUE, AND SEGMENTATION OF SUBCUTANEOUS AND VISCERAL ABDOMINAL ADIPOSE TISSUE

摘要

Adipose tissue is identified within a three-dimensional abdominal MRI image set comprising a water-only image and fat-only image of the abdomen of a subject by forming a "fat-fraction" image, which has an intensity at each voxel equal to the intensity of the fat-only image divided by the sum of the intensity of the fat-only image and the water-only image. This fat-fraction image is thresholded to form a good first approximation of the position of the adipose image. The fat-fraction image is used to obtain a threshold to segment a fat-only image. The adipose tissue is segmented into SAT and VAT by defining a graph having vertices corresponding to voxels of the abdominal image, and edges connecting neighboring vertices. Each edge is given a weight. The graph is partitioned into background and SAT portions using a partition which minimizes the sum of the weights of the edges spanning the partition, and the adipose tissue to either side of the partition is respectively labeled as VAT and SAT. Experiments utilising the invention achieved excellent correlations ( r = 0.998 for SAT and r = 0.965 for VAT) with the manual measurements and reproducibility (CV=1.5% for SAT and CV=2.3% for VAT), which rivals that of CT-based measurements.