Diffusion-weighted imaging of biliopancreatic disorders: Correlation with conventional magnetic resonance imaging

Table 1 Characteristic diffusion-weighted magnetic resonance imaging features in the various biliopancreatic tract disorders

Categories	Diagnosis	Characteristic DWI features
DWI for the evaluation of gallstone-related complications	Acute cholangitis	Hyperintense parenchyma on low b values usually returns to isointense on high b values
	Hepatic abscess	Hyperintense on high b values with low ADC values
	Acute pancreatitis	Hyperintense on high b values
DWI for the characterization and diagnosis of gallbladder lesions	Cholecystitis	Diffuse and symmetric hyperintensity in the gallbladder wall on high b values Pus in the dependent portion: hyperintense on high b values with low ADC values
	Gallbladder carcinoma	Hyperintense mass occupying the entire gallbladder lumen or focal and asymmetric hyperintensity in or around the gallbladder wall on high b values
DWI for the characterization of intrahepatic biliary lesions and diagnosis of malignant lesions in the intrahepatic bile duct	Mass-forming cholangiocarcinoma	Hyperintense on high b values with low ADC values, similar to that of other malignant hepatic masses
	Periductal-infiltrative cholangiocarcinoma	Hyperintense periductal thickening along the bile duct on high b values with low ADC values
	Intraductal-growing cholangiocarcinoma	Hyperintense intraluminal filling defect on high b values with low ADC values
	HCC with bile duct thrombi	Similar to that of intraductal-growing cholangiocarcinoma
DWI for characterization of extrahepatic biliary lesions and diagnosis of malignant lesions in the extrahepatic bile duct	Extrahepatic cholangiocarcinoma	Hyperintense on high b values with low ADC values, at the transition point from large obstructed to small-caliber decompressed ducts
	Pancreatic carcinoma	Lower ADC values than those of the remaining pancreas
	Mass-forming pancreatitis	Similar ADC values to those of remaining pancreas
	Ampullary or periampullary carcinoma	Mild to moderate hyperintensity in or around ampulla of Vater on high b values with low ADC values
	Sphincter Oddi dysfunction or papillary stenosis	Isointensity in or around ampulla of vater on high b values

DWI: Diffusion-weighted magnetic resonance imaging; HCC: Hepatocellular carcinoma; ADC: Apparent diffusion coefficient.