Background: It is essential to differentiate sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) from primary sclerosing cholangitis (PSC) as the treatment and prognosis of the two diseases are totally different.
Purpose: To compare image findings of SC-AIP and PSC on endoscopic retrograde cholangiography (ERC), magnetic resonance cholangiography (MRC), computed tomography (CT), and magnetic resonance imaging (MRI).
Material and methods: Two radiologists retrospectively reviewed ERC, MRC, CT, and MRI in 28 SC-AIP and 23 PSC patients in consensus. Factors evaluated included the length, location, and multiplicity of bile duct stricture, the presence of characteristic cholangiographic features of PSC on ERC and MRC, and the presence, location, thickness, and pattern of bile duct wall thickening on CT and MRI.
Results: On ERC, focal stricture, multifocal and intrahepatic bile duct stricture, and beaded, pruned-tree, and diverticulum-like appearance were more frequent in PSC than in SC-AIP patients (P ≤ 0.006). On MRC, multifocal and intrahepatic bile duct stricture and pruned-tree appearance were more frequent in PSC than in SC-AIP patients (P ≤ 0.044). On CT and MRI, the bile duct wall was thicker (5.1 mm vs. 3.1 mm; P = 0.033 and 4.3 mm vs. 3.0 mm; P = 0.01, respectively) in SC-AIP than in PSC patients. PSC was more frequently associated with intrahepatic bile duct wall thickening on both CT (93% vs. 50%; P = 0.024) and MRI (100% vs. 50%; P = 0.023) than SC-AIP.
Conclusion: The combination of ERC or MRC with cross-sectional images, including CT and MRI, may be helpful in differentiating between SC-AIP and PSC.
Keywords: CT; MR; Sclerosing cholangitis with autoimmune pancreatitis; cholangiography; primary sclerosing cholangitis.