Malignant biliary hilar stenosis: MR cholangiopancreatography compared with endoscopic retrograde cholangiography [Stenosi maligne ilari delle vie biliari: Correlazione tra la colangiografia con risonanza magnetica e le colangiografie dirette]

Aim. To assess the diagnostic value of three-dimensional (3D) magnetic resonance cholangiography (MRC) versus direct cholangiography such as endoscopic retrograde cholangiography (ERC) and percutaneous transhepatic cholangiography (PTC) in malignant biliary stenosis. Material and methods. Twenty-nine patients (15 female and 14 male) (mean age 62 years) with malignant biliary strictures underwent MRC and ERC. Breath-hold 3D steady state free precession MR cholangiography was performed on a 1.5-T imager in the patients before ERC. In 25 patients findings at ERC/PTC were considered the standard of reference: 19 patients underwent ERC, 5 PCT and 1 both ERC and PTC due to unsuccessful papilla cannulation during the endoscopic examination. In the 4 remaining patients the surgical specimen was considered the standard of reference. In the 29 patients studied, histology performed during direct cholangiography and the examination of the surgical specimens demonstrated that the malignant hilar stenoses were caused by hilar cholangiocarcinoma (n=7), cholangiocarcinoma of the distal VBP (n=1), gallbladder cancers (n=6), endometrial metastasis (n=2), ovary metastasis (n=1), colon metastasis (n=1), breast metastasis (n=1). The correct identification of biliary stenosis and extension of the tumor (according to the Bismuth classification) by MR cholangiography and ERC were independently assessed by two readers blinded to each other's report. The results were compared. Results. Identification of biliary stenosis and neoplastic extension were accurate in respectively 29/29 (100%) and 26/29 (89%) cases with MR cholangiography. The comparison of ERC/PTC and MRC images yielded the following results: Bismuth Type I (6 vs 6), Type II (5 vs 8), Type III (13 vs 10), Type IV (5 vs 5). Our results indicate that MR is less capable of identifying the extension of small lesions at the primary confluence of bile ducts than are ERC/PCT. Discussion and conclusions. MR cholangiography is a non-invasive technique for biliary tract imaging. It does not require administration of contrast medium and allows complete visualisation of the biliary ducts. MR cholangiography allowed accurate diagnosis of malignant hilar stenosis providing equal information as direct cholangiography and may therefore obviate the need for ERC/PTC.