3.0T磁共振T1反转角对Gd-EOB-DTPA磁共振胆管造影术胆管显示的研究

A research on the imaging effect of bile duct imaging of flip angle T_1 of 3.0T MR of Gd-EOB-DTPA MRC

目的:通过对比不同反转角(FA)在钆乙氧基苯甲基二乙烯五胺乙酸(Gd-EOB-DTPA)磁共振胆管造影术(MRC)肝胆特异期胆管系统显示能力的差异,确定合理扫描参数。方法:对临床需要行Gd-EOB-DTPA MRC检查的15例拟诊肝脏非胆管性占位病变患者,排除肝脏及胆管系统病变,于肝胆特异期第20~30 min行FA值9°、25°冠状位扫描成像,每个FA值所得到的图像归为一组。采用"3分法"分别评价FA值9°、25°时胆总管、肝总管、左右肝管、肝内二级胆管、肝内二级以下胆管和胆囊管的显示情况,并分别测量胆总管、肝总管、左肝管和右肝管的对比噪声比。各级胆管的显像主观评分比较应用秩和检验,客观比较应用两独立样本比较的t检验。结果:注药后20~30 min,FA值为9°与25°时的胆总管、肝总管、左右肝管、肝内二级胆管、肝内二级以下胆管和胆囊管显示主观评分比较差异有统计学意义(t=20.88,t=31.65,t=39.78,t=29.36,t=40.21,t=23.32;P<0.05);胆总管、肝总管、左肝管和右肝管的对比噪声比比较差异有统计学意义(t=14.76,t=10.75,t=11.69,t=8.13;P<0.05)。不同FA值下肝内外胆管显示有明显差异,FA值为25°时明显优于9°的FA值。结论:在3.0T磁共振Gd-EOBDTPA MRC胆管成像时,加大FA值能有效提高胆管的显示能力。

Objective To determine reasonable scan parameter through compared the difference of imaging effectof bile duct system in specific period of liver and gall under different flip angle of Gd-EOB-DTPA MRC. Methods：15 patients with suspected space occupying lesion of non-bile duct, who were ruled out the lesion of liver and bileduct system, and who need receive the detection of Gd-EOB-DTPA MRC, were implemented coronary scan whenFA value respectively were 9° and 25° in the 20th and 30th min of specific period of liver and gall. And the images ofeach FA value were collected in one group. And the ＂3 scores method＂ was applied to evaluate the imaging effects ofcommon bile duct, common hepatic duct, left and right hepatic duct, the secondary bile duct in liver, bile duct belowsecond grade in liver and ductus cysticus. And the contrast noise ratio of common bile duct, common hepatic duct,left and right hepatic duct were measured, respectively. The rank sum test was applied to compare the subjectivescores about imaging effect of bile ducts of different levels, and the t-test of two independence samples was appliedto compare objective assessment. Results： 20-30 min after drug was injected, the differences of subjective scoresfor the imaging effects of common bile duct, common hepatic duct, left and right hepatic duct, the secondary bileduct in liver, bile duct below second grade in liver and ductus cysticus between FA9° and FA25°were statisticallysignificant （t=20.88, t=31.65, t=39.78, t=29.36, t=40.21, t=23.32, P〈0.05）. And the differences of the contrastnoise ratio for common bile duct, common hepatic duct, left and right hepatic duct between FA9° and FA25°alsowere statistically significant （t=14.76, t=10.75, t=11.69, t=8.13, P〈0.05）. Besides, there was obvious difference inthe imaging effects of intra- and extra-hepatic bile duct between different FA values, and the imaging effect of FA25°was obviously better than that of FA9°. Conclusion： When the 3.0T MR Gd-EOB-DTPA MRC is applied to scan bileduct, the imaging effect of bile duct can be enhanced through increases FA value.