MR-IMAGING OF NONCANCEROUS HEPATIC-LESIONS IN LONG-EVANS CINNAMON RATS

We measured MR images of the liver of Long-Evans Cinnamon (LEG) rats w ith pathologic correlation and assessed the effectiveness of MR imagin g (MRI) for diagnosis of noncancerous hepatic lesions, T-1- and T-2-we ighted images of their livers were obtained, and the dynamic and delay ed studies after intravenous gadolinium injection were also performed, Cholangiofibrosis showed low signal intensity on T-1-weighted images and high signal intensity on T-2-weighted images, The T, relaxation ti me of cholangiofibrosis was significantly prolonged (p < .01), and the signal intensity ratio of this lesion to muscle on T-1-weighted image s was significantly lower than that of normal liver parenchyma to musc le (p < .01), The lesion was enhanced immediately after gadolinium inj ection and the enhancement was prolonged, Among three cases of peliosi s hepatis identified, one showed heterogeneous intensities on both T-1 - and T-2-weighted images and the other two showed similar intensity p attern to cholangiofibrosis. The characteristic MR appearance of chola ngiofibrosis may be useful to distinguish it from hepatocellular carci noma (HCC).