动态增强MR血管成像对活体肾移植供体术前的评估

Evaluation of renal vascular in living donors before transplantation using dynamic contrast enhanced MR angiography

目的 探讨动态增强MRA对活体肾移植供体血管解剖的显示情况.方法 35名肾移植供体,术前行MRA检查.首先经静脉注入1 ml对比剂Gd-DTPA,测出循环至肾动脉时间.然后行冠状面3D T1加权快速扰相小角度梯度回波（3D FLASH）序列扫描.自动脉期开始连续扫描4期,每期间隔10 s,获得肾动脉、肾静脉、集合系统等各期图像.2名放射科医师观察原始图像及MIP重组后图像,观察肾动脉、肾静脉及其分支的显示情况,确定血管的走形及有无变异.并把MRA图像质量确定为5级,与32名手术结果进行比较.结果 MRA对于肾动脉、肾静脉系统的显示质量均较好.35名供者70个肾脏中发现5支左肾副动脉,9支右副肾动脉.3支左肾动脉过早分支,6只右肾动脉过早分支,其中1支右侧双肾静脉,2例左侧精索静脉粗大.1例右肾副上极动脉MRA术前未发现.结论 动态增强MRA安全无创,对肾动脉、肾静脉显示清楚,诊断变异准确度高,是术前肾移植供体血管评价较好的影像检查手段.

Objective To explore whether dynamic contrast-enhanced MRA （DCE MRA） can provide an effective assessment of renal vascular in living donors before transplantation.Methods Thirty five healthy living renal donor candidates were scanned on MR system before transplantation.After injection of Gd-DTPA 1 ml in vein, a test-bolus scan was used to get the time delay of Gd-DTPA reaching renal artery.Then, a 3D T1-weighted fast low-angle shot sequence （3D FLASH） was performed in the coronal plane.The 3D FLASH scan would repeat four times with an inter-phase of 10 seconds.Thus, the imaging of the renal arterial, venous and collecting systems were got.Two radiologists observed renal arteries and veins on original imaging and MIP reconstructed imaging.The quality of MR angiography was evaluated on a fivepoint scale and the vascular anatomy or variations of the arterial and venous systems were recorded, using intraoperative findings as a standard of reference.Results The quality for all MRA was good or very good for the most of living renal donors.Among 70 renals, several variations of vascular were found, including 5 left accessory artery, 9 right accessory artery, 3 left proximal arterial branch and 6 right proximal arterial branch.Among 70 renal veins, 1 right accessory veins and 2 left varieocele were observed.One small accessory artery of right kidney was missed with DCE MRA, but identified by operation.Conclusion DCE MRA was noninvasive tool for evaluation of the renal vasculature and variations with high accuracy.It would be a good modality in preoperative evaluation of living renal donors.