Figure 3c. Acute cholecystitis caused by cystic duct obstruction due to gallbladder cancer with lymph node metastasis in a 64-year-old man with right upper quadrant pain. MR imaging was performed because the cause of the gallbladder distention could not be determined with US. (a) Image from single-section MR cholangiopancreatography shows a distended gallbladder with a hypointense tumor (arrow) adjacent to the gallbladder neck. The tumor mimics an impacted stone (cf Fig 2). There is a polypoid skip lesion (*) in the gallbladder body. (b) On an axial fat-suppressed T2-weighted image, the gallbladder neck tumor (solid arrow) has intermediate signal intensity. The thickened gallbladder wall has high signal intensity (open arrow). (c) On a coronal steady-state coherent image, the gallbladder neck tumor (arrow) has intermediate signal intensity, as does the liver. The skip lesion in the gallbladder body (*) has an irregular surface. The diagnosis of gallbladder cancer was confirmed at surgery and pathologic analysis.