SPLENIC HEMANGIOMAS AND HAMARTOMAS - MR-IMAGING CHARACTERISTICS OF 28LESIONS

PURPOSE: To determine the magnetic resonance (MR) imaging features of splenic hemangiomas and hamartomas, including their pattern of dynamic contrast material enhancement. MATERIALS AND METHODS: The appearance of 28 lesions in 18 patients was retrospectively reviewed on T2-weight ed images (16 patients), unenhanced T1-weighted images (18 patients), and dynamic contrast-enhanced T1-weighted images (17 patients). Sevent een of 23 hemangiomas and all five hamartomas were proved at pathologi c examination. RESULTS: Of the 22 hemangiomas imaged with T2-weighting , 19 were hyperintense, two were isointense, and one was hypointense r elative to the spleen. Dynamic gadolinium-enhanced imaging demonstrate d a progressive centripetal pattern of enhancement in 19 of 22 hemangi omas. On delayed images, 19 hemangiomas demonstrated uniform enhanceme nt, Of the five hamartomas, four were imaged with T2-weighting; three were hyperintense and one was hypointense relative to the spleen. All hamartomas demonstrated diffuse heterogeneous enhancement on images ob tained early after administration of contrast material and became more uniformly enhanced on delayed images. CONCLUSION: Splenic hemangiomas showed signal intensity characteristics and enhancement patterns simi lar to those described for hepatic hemangiomas. Since these features h ave been shown to reliably distinguish hemangiomas from other benign a nd malignant liver lesions, it may be reasonable to consider without h istologic verification that lesions in the spleen with these imaging f eatures represent hemangiomas.