Magnetic resonance imaging and computed tomography in long-term-functioning duct-occluded pancreas allotransplants

Duct-occluded segmental-pancreas transplants develop progressive fibrotic atrophy, even though endocrine function seems to be unaffected. To determine end-stage size of the graft and to evaluate magnetic resonance imaging (MRI) and computed tomography (CT), these imaging techniques were applied in eight patients with well-functioning intraperitoneal prolamine-injected segmental-pancreas transplants for 79, 48, 35, 20, 19, 19, 18, and 10 mo. MRI was performed on a 1.5 Tesla system (Philips Gyroscan S15). T1- and T2-weighted images were acquired. CT (Siemens Somatom 2) was done before and after intravenous contrast agent. The graft was visualized in seven of eight patients with both techniques. Visualization with MRI (vs. CT) was considered excellent in 2 (vs. 1), good in 3 (vs. 6), and poor in 2 (vs. 0). The three grafts with function longer than 2 yr measured 3-4 cm in length; the remaining grafts measured 3-6 cm. Because of a marked decrease in size the transplants were no longer localized in Douglas' pouch but adjacent to or on top of the uterus or bladder, the position depending on the volume of these organs. The allografts exhibited an inhomogeneous structure with casual cystic degeneration visible with MRI due to a high signal intensity on T2-weighted images. This study suggests that shrinkage of the duct-occluded pancreatic segment due to exocrine atrophy may be terminated after approximately 2 yr. It is concluded that thereafter an overshooting fibrosis causing late endocrine graft failure may not be anticipated.