Cavernous hemangioma of the liver: pathologic correlation with high-field MR imaging.

OBJECTIVE: MR imaging is used to characterize cavernous hemangiomas of the liver because these neoplasms have a long transverse relaxation time compared with normal liver parenchyma and other hepatic neoplasms. The purpose of this study was to correlate the pathologic findings of hemangiomas with their appearance on high-field MR images and with mean T2 relaxation time.

MATERIALS AND METHODS: Tissue cores were obtained by percutaneous needle biopsy of 14 cavernous hemangiomas, ranging in size from 1.0 to 10.9 cm. Mean relaxation time was determined from T2-weighted spin-echo MR images. Pathologic analysis included quantification of endothelial cells, identified by counterstaining to anti-factor VIII antibody.

RESULTS: We found an inverse relationship between the number of endothelial cells in the histologic specimen and the mean T2 value of the tumor (r = -.75; p < .002). Pathologic examination of tissue from three tumors with the shortest T2 relaxation times showed relatively greater amounts of connective tissue and more numerous but small and compressed vascular channels. Although the two hemangiomas less than 2 cm in diameter had T2 times less than 80 msec, no significant relationship between tumor size and relaxation time was found.

CONCLUSION: We conclude that T2 relaxation time of cavernous hemangioma is directly related to the collective size of its constituent vascular spaces. We found no statistically significant difference in measured T2 relaxation time and no difference in histologic appearance between hemangiomas smaller than 2 cm and larger tumors.