MR signal intensity changes in hepatic parenchyma with ductal dilation caused by intrahepatic cholangiocarcinoma

Abstract

MR images of the liver in 13 patients with surgically proven intrahepatic cholangiocarcinoma were reviewed retrospectively and correlated to the histologic analysis of surgical specimens. We paid special attention to the peripheral liver tissue with ductal dilation but without tumorous involvement. High signal intensity was observed in the hepatic parenchyma with ductal dilation on T1-weighted spin-echo images (8 of 12) and spoiled gradient-recalled echo images (seven of seven), as compared with the contralateral hepatic lobe without duct dilation. The high signal intensity was not suppressed with fat saturation and showed enhancement after administration of contrast (11 of 12). Concurrent portal venous obstruction did not have significant effect on these findings (P < .05). Correlation with pathologic specimens suggested that this enhancement was associated with periportal fibrosis. The etiology of the high signal intensity on unenhanced spin echo or gradient-recalled T1-weighted image remains unclear. Radiologists should recognize these findings and should distinguish these from tumor involvement or the arterial buffer response caused by portal venous obstruction.

Magnetic resonance imaging of cholangiocarcinoma

“…Occasionally, a high signal intensity on pre-gadolinium T1W images is seen in the periphery of the segments or lobes in which the tumor is present without portal obstruction, usually around areas of duct dilatation distal to the tumor [50]. These areas show persistent increased enhancement compared to the liver parenchyma in all phases of enhancement following gadolinium administration.…”

“…No tumor has been shown in these areas on pathology and the delayed enhancement is probably associated with periportal fibrosis secondary to duct dilatation, but the etiology of the high signal intensity on pre-gadolinium T1W images is unclear. It is important not to confuse these areas with foci of metastatic tumor, or the arterial buffer response (transient hepatic intensity difference, THID) caused by portal venous obstruction [50]. …”

Pitfalls in the Imaging Diagnosis of Hepatocellular Nodules in the Cirrhotic and Noncirrhotic Liver

“…This may reflect a high concentration of copper in the jaundiced liver tissue [33] or the presence of waste pigment of lipofuscin [34]; however, the exact mechanism remains unknown. More frequently, areas with ductal obstruction show delayed enhancement on MR images, which is attributed to increased interstitial space, pathologically seen as periportal fibrosis and ductular proliferation [33]. Prolonged ductal obstruction may result in the atrophy of the distal liver tissue, and thus the portal venous supply .…”