The application of three-dimensional breath-hold gradient and spin-echo sequence in the MR cholangiopancreatography / 中华放射学杂志

ABSTRACT

Objective:To evaluate the clinical feasibility and image quality of three-dimensional breath-hold gradient and spin-echo (3D BH-GRASE) sequence in magnetic resonance cholangiopancreatography (MRCP).Methods:In this prospective study, 59 patients with clinically suspected pancreaticobiliary duct disease performed MRCP with both 3D BH-GRASE and 3D respiration-triggered turbo spin-echo (3D RT-TSE) sequences on 3.0 T scanner in the Affiliated Zhangjiagang Hospital of Soochow University from November 2017 to December 2018. The overall image quality was scored independently by 3 experienced radiologists based on the visibility of different anatomical features of the pancreaticobiliary duct. For comparing the 2 sequences, the statistical difference in scan time was assessed with a paired t test; while subjective scores, signal-to-noise ratios (SNR), contrast ratios (CR) and contrast noise ratios (CNR) were compared with Wilcoxon signed rank test. Results:The scan time of 3D BH-GRASE sequence was 16.4 s while that of 3D RT-TSE was (258.6±42.2) s. Their difference was statistically significant ( t=44.073, P<0.001), with the scan time for 3D BH-GRASE shortened by 94%. The overall quality scores of 3D BH-GRASE images were better than those of 3D RT-TSE ( Z=-6.595, P<0.001). There was no statistical difference ( P>0.05) in the scores regarding the visibility of the upper, middle and lower parts of common bile duct and the first and second branches of left and right hepatic ducts. For visualizing the bottom, body, neck and duct of gallbladder, the 3D BH-GRASE sequence received a higher score than the 3D RT-TSE sequence ( P<0.001). For displaying the proximal, middle and distal segments of main pancreatic duct, the 3D RT-TSE sequence was scored higher than the 3D BH-GRASE sequence ( P<0.05). There was no significant difference of SNR between the two sequences ( Z=0.403, P=0.687), whereas CR and CNR of 3D RT-TSE MRCP were better than those of 3D BH-GRASE MRCP ( Z=6.215, P<0.001 and Z=3.046, P=0.002, respectively). Conclusion:Under the prerequisite of ensuring image quality, a proper use of 3D BH-GRASE sequence can significantly shorten the scan time and thus greatly improve the working efficiency of MRCP examination.