Real-time volume rendering of MRCP: clinical applications

MR-cholangiopancreatography (Signa Contour 0.5T; GE/Medical Systems, Milwaukee, WI) data sets of 156 patients, obtained with a 2D T2-weighted FSE sequence, in the coronal plane, were volume rendered (Advantage Windows 3.1; GEMS) independently by two radiologists, that were asked to define the range of signal intensitics in which the signal of the pancreaticobiliary system was included and to rank the quality of native images and volume renderings. Patients had biliary stones (n=47), inflammatory ampullary stenoses (n=18), pancreaic tumors (n=12), surgical bilio-enteric anastomoses (n=19), ampullary carcinomas (n=2), pancreatic duct stone (n=1), cholangiocarcinoma (n=3) and normal pancreaticobiliary tree (n=54). Good quality volume renderings of the bile ducts were obtained for at least a maximum diameter of 1.5 mm. The quality rank agreement between volume rendering and native images was excellent (k=0.94). The correlation between the observers for the setting the signal intensity range was excellent and statistically significant (p<0.001). The correlation between the observers for the time of volume rendering was not statistically significant. Bilary stones could be displayed in 32/47 (68%) cases. The pancreatic duct stones was displayed as well. Inflammatory ampullary stenoses were detected in all cases (100%). In case of pancreatic tumors, cholangiocarcinomas and ampullary carcinomas volume rendering allowed to identify the site of stenosis. In surgical bilio-enteric anastomoses volume rendering was helpful to display the residual bilary tract, the site of anastomosis and the enteric tract. Volume rendering could be a reliable and efficient tool for the study of the anatomy and pathological changes of the pancreaticobiliary tract.