[Evaluation of a new sequence of magnetic resonance cholangio-pancreatography in thick cut and one shot acquisition].

OBJECTIVES

To assess the accuracy and reproducibility of a new magnetic resonance cholangiopancreatography sequence (MRCP), using long echo time and "single shot" acquisition (providing high-contrast thick slices: 20 mm or more), in the morphological analysis of the biliary tree and pancreatic ducts.

METHODS

Fifty four patients with biliary and/or pancreatic disease were investigated with MRCP "single shot" thick slices. Biliary ducts were explored with MRCP "single shot", coronal and oblique coronal 20 mm thick slices on a 256 x 256 matrix. Natives pictures were reviewed by three independent radiologists, from three different institutions. MRCP results were compared with reference examinations in 54 cases (direct biligraphy methods: 54, CT scan: 11, endoscopic ultrasonography: 6, surgery: 6).

RESULTS

For detection of bile duct dilatation, the agreement of MRCP "single shot" thick slices was more than 96% (Kappa > 0.92) and the inter-observer agreement was excellent (Kappa=0.92). For detection of biliary tree and/or pancreatic duct obstruction, MRCP "single shot" thick slice sensitivity was above 89% and specificity was 75%. The malignant nature of the lesions was determined with a sensitivity of 100% and a specificity of 92%. MRCP "single shot" thick slices could not differentiate pancreatic carcinomas from distal main bile duct cholangiocarcinomas. MRCP "single shot" thick slices did not detect small stones ( 3 mm) of the common bile duct.

CONCLUSION

The excellent sensitivity, specificity and inter-observer agreement of MRCP "single shot" thick slices can be used to limit invasive imaging methods in the diagnosis of extrahepatic cholestasis.