Usefulness of ultrasonography to assess the response to steroidal therapy for the rare case of type 2b immunoglobulin G4-related sclerosing cholangitis without pancreatitis: A case report

Table 2 Representative findings of the imaging modalities for immunoglobulin G4-related sclerosing cholangitis

Modality	Findings	Miscellaneous	Ref.
US	Wall thickening of the bile duct, dilatation of intrahepatic bile duct	Not specific, low sensitivity
EUS	High sensitivity	Combined with fine needle aspiration	[17-20]
IDUS	High sensitivity and specificity, high-resolution, images of the duct wall	May differentiate from cholangiocarcinoma
CT	Wall thickness, dilatation, the thickened segment shows progressive homogeneous contrast enhancement, with more enhancement seen in the delayed phase	Combined with contrast enhancement for differential diagnosis
MRI/MRCP	Bile duct wall thickening with iso-hypointense signal on T2-weighted image	Assessment of biliary system
PET	Uptake of FDG in bile duct wall
ERCP	Useful for the classification of the types	Useful for the situations in which an intervention, like stent placement, and biopsy is needed

US: Transabdominal ultrasonography; EUS: Endoscopic ultrasonography; IDUS: Intraductal ultrasonography; CT: Computed tomography; MRI: Magnetic resonance imaging; MRCP: Magnetic resonance cholangiopancreatography; PET: Positron emission tomography; ERCP: Endoscopic retrograde cholangiopancreatogr.