MRI OF PANCREATIC-ISLET CELL-CARCINOMA

Objective: The purpose of this study is to report the spectrum of MR f indings of pancreatic islet cell carcinoma. Materials and Methods: The MR scans of 33 patients with islet cell carcinoma were retrospectivel y reviewed. Magnetic resonance detected the primary tumor in 21 of 27 patients (78%) who had not had prior resection of their primary tumor. Mean tumor diameter was 7.1 cm (range 3.5-13.0 cm). Results: In all p atients, the primary tumor on T1-weighted images (TR/TE 250/15) was of signal intensity equal to or lower than that of the adjacent normal p ancreas. The primary tumor on T2-weighted images (TR/TE = 2,000/greate r-than-or-equal-to 100) was of signal intensity the same as or higher than fat in 18 of 21 patients (86%) and had mixed signal intensity in the other 3 (14%). Hepatic metastases were found in 28 of 33 patients (85%). Liver metastases were categorized as ''usual'' (variably circum scribed, homogeneous lesions of medium signal intensity on T2-weighted images) in 19 of 28 patients (68%), necrotic in 8 of 28 (29%), hemorr hagic in 3 of 28 (11%), and calcified in 1 of 28 (4%). Extrahepatic me tastases were found in 18 of 33 patients (55%). Conclusion: We conclud e that MRI is an excellent modality for the diagnosis and routine foll ow-up of patients with islet cell carcinoma.