DYNAMIC GD-DOTA-ENHANCED MR-IMAGING OF HEPATIC METASTASES FROM PANCREATIC NEUROENDOCRINE TUMORS

The aim of this study was to determine the MR imaging features of hepa tic metastases from pancreatic neuroendocrine tumors (HMPNT), and to a ssess their enhancement characteristics on dynamic gadolinium-chelate- enhanced MR imaging. Twelve consecutive patients with pathologically p roven HMPNT underwent spin-echo (SE) and dynamic gradient-recalled ech o (GRE) MR imaging before and after intravenous administration of a ga dolinium-chelate (gadolinium tetraazacyclododecanetetraacetic acid; Gd -DOTA). MR examinations were performed prospectively and interpreted r etrospectively in consensus by two radiologists. Fifty-five HMPNT were identified in matching anatomic sections on the different MR sequence s and included in the study. On T1-weighted SE images, 45 HMPNT (82%) were hypointense and 10 HMPNT (18%) were isointense. On T2-weighted SE images 55 HMPNT (100%) were hyperintense. On GRE images obtained 20 s after Gd-DOTA injection, 41 HMPNT (75%) showed slight peripheral enha ncement, and 14 HMPNT (25%) showed internal enhancement. Forty-four HM PNT (80%) were heterogeneous. On GRE images obtained 4 min after Gd-DO TA injection, 37 HMPNT (67%) showed peripheral enhancement, and 18 HMP NT (33%) showed a global and almost complete enhancement. Heterogeneit y of enhancement was seen in all 55 HMPNT (100%). Although HMPNT exhib it a large spectrum of MR features, early enhancement and heterogeneit y on dynamic GRE MR images are suggestive features of HMPNT.