MR cholangiography in biliary obstruction using Half-Fourier acquisition

Our goal was to evaluate biliary obstruction using a T2-weighted, turbo, SE MR sequence with half-Fourier acquisition (HASTE). A prospective evaluation of 21 consecutive patients with clinical evidence of obstructive jaundice was carried out comparing HASTE MR cholangiography (MRC) to endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography. A control group of five normal volunteers was also evaluated. The study group was imaged with a 1.5 T MR scanner using a body coil. The HASTE sequence was applied in axial, coronal, and oblique sagittal planes. Ultrafast acquisition scanning times allowed the use of a single breath hold. Bile duct dilatation, level of obstruction, and cause of obstruction were assessed on both imaging modalities by two radiologists blinded to the clinical diagnosis and to each other's results. All studies were interpretable with anatomy well seen in 82% of the cases. MRCs of a normal control group were correctly interpreted. The presence of biliary dilatation was accurately depicted by HASTE MRC in 100% of patients with complete interobserver agreement. The level of obstruction was depicted correctly in 87% of patients with 93% interobserver agreement. The right main duct was seen by MRC in 80% of obstructed systems. The left main duct was seen in all obstructed patients. The gallbladder was identified in 88% of patients by MRC. Common bile duct stricture and stones could be differentiated as a cause of obstruction in all cases. MRC using the HASTE imaging sequence can safely and accurately depict the presence and level of biliary obstruction. The fast acquisition time of 13 s/scan makes the technique suitable for uncooperative and ill patients. HASTE MRC should be considered an alternative procedure to direct cholangiography in selected patients.