动态增强磁共振血管成像诊断肾动脉狭窄的临床价值

目的：评价动态增强磁共振血管成像（3D CE MRA）在诊断肾动脉狭窄中的价值。方法：对40例临床诊断或怀疑肾动脉狭窄患者进行3D CE MRA检查，其中17例经DSA对照。使用马根维显（磁显葡胺）造影剂对所有患者采用Smart智能追踪技术进行动态三期扫描。综合分析三期图像进行2D多平面重建（MPR）、曲面重建（CPR）成像、3D最大强度投影（MIP）及3D遮盖表面显示（VR）方法进行重建的血管影像，观察双侧肾动脉情况，完成诊断。结果：3D CE MRA显示了40例患者总共80支肾动脉主干，显示率为100%。40例中3D CE MRA显示肾动脉正常64支，肾动脉狭窄16支。17例有DSA对照者，DSA显示肾动脉正常19支，肾动脉狭窄15支；3D CE MRA除把2支轻度狭窄估为中度狭窄，1支中度狭窄估为重度狭窄外，其它结果都同DSA一致，诊断肾动脉狭窄的敏感性、特异性、阳性预测值及阴性预测值分别为94.1%，100.0%，100.0%及95.5%。结论：3D CE MRA能清晰显示肾动脉并对肾动脉狭窄作出可靠诊断，在很大程度上可成为介入治疗前的常规检查方法。

Accuracy of three dimensional contrast enhanced MR angiography in diagnosis of renal artery stenosis

Objective: To assess the value of three dimensional contrast enhanced MR angiography(3D CE MRA) in the diagnosis of renal arterial stenosis. Methods: Forty patients suspected of renal arterial stenosis were examined by 3D CE MRA, 17 cases had DSA for comparison. All patients were injected with dimeglumine gadopentetate underwent three phases dynamic enhancement scanning by smart technology. The diagnosis was established on the basis of transverse section, multiplanar reconstruction(MPR), curved planar reformation(CPR), maximum intensity projection(MIP) and volume render(VR). Accessory renal arteries were also evaluated. Results: In the 40 cases, 80 renal arteries were clearly visualized by 3D CE MRA, 64 normal and 16 stenotic vessels. In the 17 cases with DSA, there were 19 normal, 15 stenotic vessels. The sensitivity, specificity, positive predictive value and negative predictive value of 3D CE MRA for diagnosis of renal arterial stenosis were 94.1%, 100.0%, 100.0%, and 95.5% respectively. Conclusion: 3D CE MRA was able to make a reliable diagnosis of renal arterial stenosis. 3D CE MRA should be the routine method of diagnosis of renal artery stenosis before invasive DSA in a large proportion of cases.