Diagnostic Value Of A Volumetric Interpolated Breath-hold Examination MR Imaging Sequence In Evaluating Obstructive Biliary Diseases

ObjectiveTo investigate the diagnostic value of a fast gradient-echo (GRE) three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) MR sequence in evaluating obstructive biliary diseases, by comparing with magnetic resonance cholangiopancreatography (MRCP) and two-dimensional GRE T1W sequence.Materials and methodsIn addition to conventional spin echo (SE) T2W and unenhanced 2D GRE T1W sequences, fast-SE heavily T2W single-shot thick-slice MRCP, Gd-enhanced 3-D VIBE acquisition at early arterial, late arterial and portal venous phases, and 2D GRE T1W scanning at equilibrium phase were performed for 138 consecutive patients suspected of having obstructive biliary diseases on clinic or other imaging examination basis. Among them, 132 patients with image quality suitable for diagnosis were included into the study. (1)On the basis of surgical / pathological findings (91 cases), biopsyhistology (19 cases) and clinical follow-ups (22 cases), the diagnostic values of MRCP, 3D-VIBE and 2D GRE T1W for obstructive biliary diseases were compared in terms of lesion detection, localization, characterization, histological origin speculation and lesion sub-typing. (2)The diagnostic accuracies of 3D-VIBE and 2D GRE T1W for depicting the extent of hilar cholangiocarcinoma and gallbladder carcinoma were compared.Results(D Lesion detection and localization. 118 out of 132 patients were found to have definite biliary obstruction sites, accounting for 160 foci of lesions in total. MRCP detected 149 (93.1%) lesions, significantly higher than 3D-VIBE sequence (134/160, 83.8%) and 2D GRE T1W sequence (130/160, 81.3%)(p<0.05). The difference between the latter two sequences was not statistically significant (p>0.05).(2) Lesion characterization. The diagnostic accuracies of 3D-VIBE, 2D GRE TIW and MRCP were 97.7% (129/132), 91.7% (121/132), and 84.8% (112/132) respectively. The performance of 3D-VIBE was significantly better than 2D GRE TIW and MRCP (p<0.05). There was no statistical difference between 2D GRE TIW sequence and MRCP (p>0.05).(3) Lesion histology speculation. The accuracies of 3D-VIBE, 2D GRE TIW and MRCP were 97.0% (128/132), 87.9% (116/132), and 76.5% (101/132) respectively. There was statistically significant difference between either two sequences (p<0.05), the performance of 3D-VIBE being the best.(4) Sub-typing of hilar cholangiocarcinoma. In 27 patients with hilar cholangiocarcinoma (11 infiltrative type, 16 mass-forming type), 3D-VIBE and 2D GRE T1W were all correct in classifying the tumor subtypes, butMRCP was correct in only 3 cases of infiltrative type hilarcholangiocarcinoma.(§) 3D-VIBE depicted the tumor extent of 27 cases of hilarcholangiocarcinoma and 4 cases of gallbladder carcinoma more close to thefindings of surgery and pathology than 2D GRE TIW.Conclusion3D-VIBE demonstrates superb diagnostic advantages over 2D GRE TIW and MRCP in lesion detection, localization, characterization, histological origin speculation, sub-typing and lesion spreading extent assessment in patients with obstructive biliary diseases, especially those of non-calculus etiology. 3D-VIBE sequence should be an important part of the comprehensive MR imaging evaluation for patients with obstructive biliary diseases.