Department of MRI, St Mary's Hospital, Imperial College NHS Trust, London, UK.
Eur Radiol. 2011 Jul;21(7):1470-6. doi: 10.1007/s00330-011-2086-6. Epub 2011 Feb 20.
To evaluate steady-state free precession (SSFP) non-contrast-enhanced MR angiography (Unenhanced-MRA) versus conventional contrast-enhanced MR angiography (CE-MRA) in the detection of renal artery stenosis (RAS).
Retrospective analysis of 70 consecutive patients referred for suspected RAS, examined by SSFP Unenhanced-MRA and CE-MRA. Image quality, quality of visible renal arterial segments, presence and grade of RAS were evaluated. The Unenhanced-MRA were compared against reference standard CE-MRA results.
149 renal arteries were assessed with 21 haemodynamically significant stenoses (≥ 50% stenosis) demonstrated by CE-MRA. Combined sensitivity and specificity for RAS detection by Unenhanced-MRA was 72.8% and 97.8% respectively. There is substantial correlation for RAS detection between Unenhanced-MRA and CE-MRA with kappa values of between 0.64 and 0.74. There was excellent inter-observer correlation for RAS on Unenhanced-MRA (kappa values 0.82-1.0).
Our study has shown Unenhanced-MRA to be a viable alternative to CE-MRA, yielding images equal in quality without the requirement for gadolinium contrast agents. The sensitivity and specificity for the detection of haemodynamically significant stenoses are comparable to CE-MRA. Potentially, Unenhanced-MRA could be used as an initial investigation to avoid performing CE-MRA in patients with normal renal arteries, however we suggest that its real value will lie in being complementary to CE-MRA.
评估稳态自由进动（SSFP）无对比增强磁共振血管成像（Unenhanced-MRA）与传统对比增强磁共振血管成像（CE-MRA）在检测肾动脉狭窄（RAS）中的应用。
回顾性分析了 70 例连续疑似 RAS 患者，采用 SSFP Unenhanced-MRA 和 CE-MRA 进行检查。评估图像质量、可见肾动脉节段的质量、RAS 的存在和程度。将 Unenhanced-MRA 与参考标准 CE-MRA 结果进行比较。
149 条肾动脉接受评估，CE-MRA 显示 21 条肾动脉狭窄（≥50%狭窄）有血流动力学意义。Unenhanced-MRA 检测 RAS 的敏感性和特异性分别为 72.8%和 97.8%。Unenhanced-MRA 和 CE-MRA 检测 RAS 的相关性较强，kappa 值在 0.64 至 0.74 之间。Unenhanced-MRA 上的 RAS 观察者间具有极好的相关性（kappa 值为 0.82-1.0）。
本研究表明 Unenhanced-MRA 是 CE-MRA 的一种可行替代方法，可获得质量相等的图像，而无需使用钆对比剂。检测血流动力学意义重大狭窄的敏感性和特异性与 CE-MRA 相当。潜在地，Unenhanced-MRA 可以作为一种初始检查，避免在正常肾动脉患者中进行 CE-MRA，但是我们认为它的真正价值将在于与 CE-MRA 互补。
