MR imaging and CT of extrahepatic cavernous hemangiomas.

Ten extrahepatic cavernous hemangiomas in seven patients were evaluated by MR and CT. MR was done with a 1.0-T superconducting magnet and spin-echo imaging. The lesions occurred in the musculoskeletal system, parotid gland, and spleen. MR and CT features of hemangiomas were compared, and MR findings in hemangiomas were also compared with those in eight musculoskeletal tumors of nonvascular origin. MR detected 10 hemangiomas, while nine were shown by CT. Also, MR was more accurate than CT in three patients in determining the true extent of hemangiomas. At a pulse-repetition interval of 2000 msec and an echo delay time of 90 msec, all hemangiomas were markedly hyperintense compared with skeletal muscle. Quantitatively, at this pulse sequence, intensity ratios of hemangiomas to skeletal muscle were all seven or greater (mean = 9.89), while the ratios for other tumors were usually less than seven (mean = 5.14). These means differed significantly (p less than .001). Small cavernous hemangiomas were homogeneous, well-defined round or oval lesions, while large hemangiomas consisted of dilated, tortuous vascular channels. Other tumors, however, were usually heterogeneous owing to hemorrhage and necrosis and had irregular margins. MR may, therefore, be useful for distinguishing cavernous hemangiomas from other soft-tissue tumors, particularly sarcomas.