Figure 2. Magnetic resonance cholangiopancreatography (MRCP) and magnetic resonance imaging (MRI) studies at different times during treatment of immunoglobulin G4-related disease. (A1–A3: on admission, B1–B3: after 6 weeks, C1–C3: after 5 months of treatment). A1 MRCP shows initial intrahepatic and extrahepatic biliary tree dilatation on admission (before treatment) (also see Figure 1A). B1 After 6 weeks of the steroid therapy, MRI reveals total resolution of the subhepatic common bile duct (CBD) stenosis. C1 shows a progressive CBD stenosis with dilated intrahepatic bile ducts after short discontinuation of prednisolone, about 5 months after the start of treatment. A2, B2, C2 (axial T1-weighted) and A3, B3, C3 (axial T2-weighted): In the follow-up examinations after 6 weeks (B2, B3) and 5 months later after steroid therapy (C2, C3), the pancreas appears normal-size, with resolution of the previously seen low-attenuation halo, although a high T2 signal and delayed enhancement of the parenchyma were still detectable on MRI.