L'impiego del mezzo di contrasto superparamagnetico per os nella colangiopancreatografia con Risonanza Magnetica TSE single shot. Oral superparamagnetic contrast agents in TSE single-shot MR cholangiopancreatography

PURPOSE: To investigate the yield of an oral superparamagnetic contrast agent (Lumirem) in turbo spin echo (TSE) single-shot MR cholangiopancreatography (MRCP) in patients candidate to laparoscopic cholecystectomy. MATERIAL AND METHODS: Thirty patients (mean age: 52.2 years) scheduled for laparoscopic cholecystectomy underwent MRCP with TSE single-shot sequences. To cover the biliary tree, thick-section TSE images were acquired according to the cross-sectional location of the biliary tract. Six 50-mm images progressively rotated by 30 degrees each were acquired during breath-holds. The precontrast images were obtained before the negative oral contrast agent was administered. The postcontrast images were acquired 10 minutes after oral contrast agent administration. Two observers made a qualitative evaluation on all images: the contrast enhancement was assessed comparing the pre- and postcontrast images of each examination on the basis of signal intensity in the stomach and duodenum, giving a score on a graduate scale. The greater yield of postcontrast images was validated by statistical analysis. The actual diagnostic improvement obtained with postcontrast images was validated for every single case. RESULTS AND CONCLUSIONS: The greater yield of postcontrast images was statistically significant in the common bile and cystic ducts, but not in the gallbladder and Wirsung duct. Better images were obtained in 22/30 patients. The actual diagnostic improvement in the visualization of the common bile and cystic ducts was statistically significant in 7/30 patients. To conclude, administering an oral negative contrast agent improved image quality and the diagnostic yield. The agent was well tolerated and safe and we suggest its use in TSE single-shot MRCP of the patients candidate to laparoscopic cholecystectomy.