CT and MRI findings of primary hepatic carcinoid tumor

Objective To investigate the imaging findings of primary hepatic carcinoid tumor with dynamic MRI and spiral CT.Methods Eleven cases with pathologically confirmed primary hepatic carcinoid tumor were analyzed retrospectively.Four cases were examined with spiral CT,and 8 cases were examined with MRL Results Two of 11 cases had multiple tumors,presenting as two or more nodular lesions,while the remaining 9 cases had single tumor.Four cases showed well-defined low density on the plain scan of CT,with central irregular cystic areas.Lesions enhanced unevenly on arterial phase of CT,with no enhancement in the central part The edge of lesions showed delayed reduced enhancement on portal vein phase.than the arterial phase,while non-enhanced lesions in the center areas.Eight cases were detected by MRI,seven On MRI,7 of 8 lesions showed uneven low signal on T_1WI and high signal with central low intensity on T_2WI.On arterial phase of MRI,7 cases had uneven enhancement at the peripheral part and irregular non-enhanced signal in center.Lesions showed delayed mild enhancement in the peripheral parts,with a relatively smaller non-enhanced central area.One case was cystic,with high signal included in the extensive low density on T_1WI.The case appeared high signal on T_2WI and had uneven enhancement at the edge on arterial phase,low signal on delayed phase.Conclusion Primary hepatic carcinoid tumor exhibits some imaging features on plain and dynamic contrast-enhanced MRI and spiral CT,which can be the clue for the diagnosis. Key words: Liver neoplasms; Tomography,X-ray computed; Magnetic resonance imaging