Abstract: Objective To investigate the most appropriate value of TSE factor and EPI factor for accelerated 3D GRASE-MRCP which is within 15 seconds. Methods Thirty-one patients underwent 3D GRASE-MRCP 5 times with different value of TSE factor and EPI factor at 3T， the acquisition time of each sequence was less than 15 seconds. ANOVA and pairwise comparison were used to compare the contrast-to-noise （CNR） of common bile duct between 5 groups. The images quality of 5 groups were scored by three experienced radiologists. Scoring results were analyzed statistically with the Kruskal-Wallis H test and pairwise comparison. Results The CNR of Group 5 （14*9） was significantly higher than that of Group 1 （14*7）、Group 3 （13*7）、Group 4 （14*5）. The qualitative scores for Group 1 is significantly better than that of Group 4 and 5. Conclusion The acquisition time of accelerated 3D GRASE-MRCP could be less than 15 seconds， which made it more feasible for clinical use. When the value of TSE factor and EPI factor were 14×7， it provided better CNR and image quality.

Key words: magnetic resonance cholangiopancreatography, magnetic resonance imaging, biliary tract, breath holding

摘要： 目的 通过采用不同的TSE factor、EPI factor组合，将屏气3D GRASE-MRCP序列的扫描时间缩短至15秒以内，并选出图像质量较佳的TSE factor、EPI factor组合。方法 在3.0T上对31例患者分别采用5组不同TSE factor、EPI factor组合的3D GRASE-MRCP序列进行扫描，扫描时间均在15秒以内，对所得5组图像胆总管的对比信噪比（CNR）进行方差分析及两两对比；由三名高年资的影像科医师对5组序列的成像效果目测评分，组间对比采用Kruskal-Wallis H检验及两两对比。结果 5组图像的胆总管CNR中，组1（14*7）、组3（13*7）、组4（14*5）的CNR显著高于组5（14*9），其它组间两两对比CNR均没有显著差异。专家目测评分，组1评分显著高于组4、组5，组1与组2、3间无显著统计学差异。结论 优化后的3D GRASE-MRCP序列扫描时间可缩短至15秒以内，更适用于临床。综合CNR定量分析及专家目测评分的结果，TSE factor、EPI factor的组合为14*7时图像质量较佳。

关键词: 磁共振成像, 磁共振胰胆管成像技术, 屏气, 胆管