1.

Axial post contrast CTs (A and B) and quantitative segmentation (C and D) for two representative side BD IPMN cases with main pancreatic ducts normal in caliber. Case 1 has a well-demarcated homogenous hypodense 4.8 cm cystic lesion in the pancreatic neck (yellow arrow). The cystic lesion abuts the gastroduodenal artery (red arrow) without definite encasement. Case 2 has a poorly defined 1.3 cm hypoenhancing pancreatic neck lesion (yellow arrow). C and D: (1) Axial CT image through L2–L3 intervertebral disc level. (2) Axial CT subtracted image at superior endplate of L3. Abdominal wall and paraspinal muscle area were segmented and thresholds set to voxels with Hounsfield units (HU) –29 to 150. Visceral fat, intra-abdominal organs, and vasculature were subtracted. Although skeletal muscle indices can be obtained in a complementary manner to visceral fat measurements, these were not directly analyzed in this study. (3) Total abdominal fat with HU thresholds applied to include fat density voxels with HU –249 to –49 (green). (4) Manual segmentation of visceral fat regions (green).