case_images: PMC8323408_01
case_images: Magnetic resonance cholangiopancreatography without contrast of the bile ducts: The
  liver demonstrates intrahepatic duct dilation. The left hepatic duct measures 13 mm and
  the right hepatic duct measures 12 mm. There is a filling defect in the proximal common
  bile duct suggestive of a calculus. Contour of the bile ducts is irregular and
  ragged.
case_images: 10.1177_2050313X211035573-fig1.jpg
case_images: PMC8323408_01_10.1177_2050313X211035573-fig1.jpg
case_images: fig1-2050313X211035573
case_images: MRCP revealed left and right hepatic duct dilation and a filling defect in the proximal common bile duct suggestive of a calculus (Figure 1).
case_images: Endoscopic retrograde cholangiopancreatography showing the "Arrowhead sign" (red
  arrows). The arrowhead appearance of the bile ducts is reflected by the decreased
  arborization of the peripheral ducts and multiple intrahepatic biliary structures. The
  rapid tapering of the intrahepatic ducts resulting to less acute branching patterns is
  due to extensive periductal fibrosis.
case_images: 10.1177_2050313X211035573-fig2.jpg
case_images: PMC8323408_01_10.1177_2050313X211035573-fig2.jpg
case_images: fig2-2050313X211035573
case_images: Subsequent endoscopic retrograde cholangiopancreatography (ERCP) was consistent with extensive periductal fibrosis (Figure 2).