肾动脉狭窄的三维增强磁共振血管成像诊断

目的:评价高分辨力三维增强磁共振血管成像术(3DCEMRA)对肾动脉狭窄的显示准确性。方法:对30例临床诊断或怀疑肾动脉狭窄患者进行高分辨力肾动脉3DCEMRA检查,分析所有患者的肾动脉和副肾动脉显示质量和病变显示情况,并与DSA做对照。结果:3DCEMRA显示了30例患者总共59支肾动脉主干(1例为单支移植肾动脉),显示率为100%。3DCEMRA显示4支副肾动脉,显示率100%。肾动脉段级分支的显示率为49%。所有病例在动脉显示区域内静脉均未显影或显影淡,对诊断不构成影响。DSA共显示59支肾动脉主干和4支副肾动脉(以63支计算),59支主干中2支闭塞,8支重度狭窄,11支中度狭窄,10支轻度狭窄,28支肾动脉主干和4支副肾动脉都正常。3DCEMRA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,故3DCEMRA显示肾动脉主干和副肾动脉狭窄程度超过50%的有血液动力学意义的明显狭窄的敏感性和特异性分别为100%和95%,阳性预测值为91%,阴性预测值为100%。结论:高分辨力肾动脉3DCEMRA能准确检出肾动脉主干和副肾动脉狭窄,并能较好判断其狭窄程度。

Diagnosis of Renal Artery Stenosis with 3D Contrast Enhanced MR Angiography

Objective:To evaluate the diagnostic accuracy of high-resolution 3D contrast-enhanced MR angiography in detecting renal artery stenosis.Methods:Thirty patients with clinically diagnosed or suspected renal artery stenosis underwent high-resolution 3D contrast-enhanced MR angiography (3D CE MRA) of the renal arteries.The overall image quality and depiction of the stenosis were evaluated.The demonstration of vascular pathology was compared with that on DSA. Results:3D CE MRA identified all 59 main renal arteries (one case of single transplant renal artery) in 30 subjects (100%).3D CE MRA showed all 4 accessory renal arteries.The depiction rate of segmental renal arteries was 49%.Venous contamination was rated as none or minimal and not interfered with arterial diagnosis.DSA revealed 59 main renal arteries and 4 accessory arteries (63 in total).Of the 59 main renal arteries,2 were occluded,8 were severely stenotic,11 were moderately stenotic,10 were mildly stenotic,and 28 were normal.4 accessory arteries were normal.3D CE MRA led to correct grading of these stenoses except 2 over gradings of mild stenosis as moderate and 1 over grading of moderate stenosis as severe.Accordingly this technique was 100% sensitive and 95% specific in the diagnosis of hemodynamically significant stenosis of the main and accessory renal arteries.The positive and negative predictive values were 91% and 100% respectively. Conclusion:High-resolution 3D CE MRA of the renal arteries was reliable to reveal and grade renal artery stenosis.