Primary sclerosing cholangitis: MR imaging findings with pathologic correlation

OBJECTIVE. The purpose of this study was to evaluate MR imaging findings of primary sclerosing cholangitis, to compare them with histopathologic findings, and to determine if these findings help differentiate primary sclerosing cholangitis from other disorders that result in end-stage liver disease. MATERIALS AND METHODS. MR imaging was performed in 40 patients (27 men, 13 women; age range, 13-72 years; mean, 47 years) with primary sclerosing cholangitis over a 9-year period. In 16 patients who underwent orthotopic hepatic transplantation and in seven patients who underwent needle biopsy, correlation was made between MR imaging and pathologic findings. RESULTS. Focal signal changes in the liver parenchyma were seen on T2-weighted images as peripheral wedge-shaped zones of increased signal intensity in 29 patients (72%), as a reticular pattern in 15 patients (38%), and as periportal edema in 16 patients (40%). Lobar atrophy involved the right lobe in three patients (8%) and the left lobe in 11 patients (28%); hypertrophy of the caudate lobe was seen in nine patients (23%). Features of portal hypertension were seen in 14 patients (35%). Histologic assessment showed zones of segmental atrophy and scarring on the periphery of the liver. CONCLUSION. Peripheral wedge-shaped areas of high T2 signal intensity and dilatation of bile ducts are characteristic MR features of primary sclerosing cholangitis. Pathologic correlation suggests that these features may be related to underlying perfusion changes and bile duct inflammation in patients with primary sclerosing cholangitis.