CAVERNOUS HEMANGIOMA OF THE LIVER - PATHOLOGICAL 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 t ime 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 me an T2 relaxation time. MATERIALS AND METHODS. Tissue cores were obtain ed by percutaneous needle biopsy of 14 cavernous hemangiomas, ranging in size from 1.0 to 10.9 cm. Mean relaxation time was determined from TS-weighted spin-echo MR images. Pathologic analysis included quantifi cation of endothelial cells, identified by counterstaining to anti-fac tor VIII antibody. RESULTS. We found an inverse relationship between t he number of endothelial cells in the histologic specimen and the mean T2 value of the tumor (r=-.75; p<.002). Pathologic examination of tis sue from three tumors with the shortest T2 relaxation times showed rel atively greater amounts of connective tissue and more numerous but sma ll 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. CONCLUS ION. We conclude that T2 relaxation time of cavernous hemangioma is di rectly related to the collective size of its constituent vascular spac es. We found no statistically significant difference in measured T2 re laxation time and no difference in histologic appearance between heman giomas smaller than 2 cm and larger tumors.