Angeretti M G, Lumia D, Canì A, Barresi M, Nocchi Cardim L, Piacentino F, Maresca A M, Novario R, Genovese E A, Fugazzola C
Department of Radiology.
Acta Radiol. 2013 Sep;54(7):749-56. doi: 10.1177/0284185113482690. Epub 2013 Apr 30.
The main causes of renal artery stenosis (RAS) are atherosclerosis and fibromuscular dysplasia. Despite contrast-enhanced magnetic resonance angiography (CE-MRA) being a safe and reliable method for diagnosis of RAS especially in young individuals, recently it has been possible to adopt innovative technologies that do not require paramagnetic contrast agents.
To assess the accuracy of steady-state free-precession (SSFP) non-contrast-enhanced magnetic resonance angiography (NC-MRA) by using a 1.5 T MR scanner for the detection of renal artery stenosis, in comparison with breath-hold CE-MRA as the reference standard.
Sixty-three patients (33 men, 30 women) with suspected renovascular hypertension (RVHT) were examined by a 1.5T MR scanner; NC-MRA with an electrocardiography (ECG)-gated SSFP sequence was performed in 58.7% (37/63) of patients; in 41.3% (26/63) of patients a respiratory trigger was used in addition to cardiac gating. CE-MRA, with a three-dimensional gradient echo (3D-GRE) T1-weighted sequence, was performed in all patients within the same session. Maximum intensity projection (MIP) image quality, number of renal arteries, and the presence of stenosis were assessed by two observers (independently for NC-MRA and together for CE-MRA). The agreement between NC-MRA and CE-MRA as well as the inter-observer reproducibility were calculated with Bland-Altman plots.
MIP image quality was considered better for NC-MRA. NC-MRA identified 143 of 144 (99.3%) arteries detected by CE-MRA (an accessory artery was not identified). Fourteen stenoses were detected by CE-MRA (11 atherosclerotic, 3 dysplastic) with four of 14 (28.5%) significant stenosis. Bland-Altman plot demonstrated an excellent concordance between NC-MRA and CE-MRA; particularly, the reader A evaluated correctly all investigated arteries, while over-estimation of two stenoses occurred for reader B. Regarding NC-MRA, inter-observer agreement was excellent.
NC-MRA is a valid alternative to CE-MRA for the assessment of renal arteries.
肾动脉狭窄（RAS）的主要病因是动脉粥样硬化和纤维肌发育不良。尽管对比增强磁共振血管造影（CE-MRA）是诊断RAS的一种安全可靠的方法，尤其是在年轻个体中，但最近已经可以采用不需要顺磁性造影剂的创新技术。
与屏气CE-MRA作为参考标准相比，评估使用1.5T MR扫描仪的稳态自由进动（SSFP）非对比增强磁共振血管造影（NC-MRA）检测肾动脉狭窄的准确性。
63例疑似肾血管性高血压（RVHT）的患者（33例男性，30例女性）接受了1.5T MR扫描仪检查；58.7%（37/63）的患者采用心电图（ECG）门控SSFP序列进行NC-MRA检查；41.3%（26/63）的患者除心脏门控外还使用了呼吸触发。所有患者在同一会诊期间均采用三维梯度回波（3D-GRE）T1加权序列进行CE-MRA检查。由两名观察者评估最大强度投影（MIP）图像质量、肾动脉数量和狭窄情况（NC-MRA独立评估，CE-MRA共同评估）。使用Bland-Altman图计算NC-MRA和CE-MRA之间的一致性以及观察者间的可重复性。
NC-MRA的MIP图像质量被认为更好。NC-MRA识别出CE-MRA检测到的144条动脉中的143条（99.3%）（未识别出一条副动脉）。CE-MRA检测到14处狭窄（11处动脉粥样硬化性，3处发育异常性），其中14处中有4处（28.5%）为显著狭窄。Bland-Altman图显示NC-MRA和CE-MRA之间具有极好的一致性；特别是，读者A正确评估了所有研究的动脉，而读者B高估了两处狭窄。关于NC-MRA，观察者间的一致性极好。
NC-MRA是评估肾动脉的一种有效的CE-MRA替代方法。
