Study of CT and MRI Diagnosis for the Pancreatic Lipomas

Objective: The purpose of this study was to investigate the value of CT and MRI in diagnosing pancreatic lipomas. Materials and Methods: A retrospective study was carried out in 9 patients with pancreatic lipomas. CT scanner was Lightspeed multi-slice device, MRI system was Signa Excite HD 3.0T superconducting unit. The patients included four male and five female, their ages ranged from 35 to 75 years old, mean 51 years old. Two experienced doctors analyzed CT and MRI findings of the lipomas, including morphology, density and enhancing appearance on CT(<i<n</i< = 7), as well as MR signal intensity in various pulse sequence and enhancing appearance in T1 WI following administration of Gd-DTPA on MRI(<i<n</i< = 2). Results: The size of the lipomas in the nine cases ranged from 0.7 cm × 0.7 cm to 3.37 cm × 4.2 cm, mean size was 1.57 cm × 2.3 cm in the axial imaging plane. The lesions located in the pancreatic head in 5, pancreatic body in 3, pancreatic tail in 1 case, and they appeared as round shape in 2, oval shape in 5 and irregularity in 2 cases. CT revealed well-circumscribed masseswith fatty density in the pancreas, the measured CT value was between-74 Hu and-108 Hu, mean value was-91 Hu ± 3.01 Hu. Obvious enhancement was not observed on post-contrast CT following iodine contrast administration, the CT value was between-66 Hu and-98 Hu, mean value was-87 Hu ± 2.15 Hu, a slight rise was noted somehow by comparing with the pre-contrast CT scans. No statistically significant difference was found between mean CT value of pre- and post-contrast CT scan(<i<P</i< ＞ 0.05). A few scattered shadows indicating vessels and/or septa may be seen within larger lipomas. On MRI examinations, the lipomas showed high signal intensity on conventional T1 WI and T2 WI, but low signal intensity on fat-suppressed T1 WI and T2 WI, the alterations of the MR signal intensity are consistent with those of the fatty tissue around the pancreas. Conclusion: CT and MRI examinations were definitely diagnostic for lipomas of the pancreas.