François Christopher J, Tuite David, Deshpande Vibhas, Jerecic Renate, Weale Peter, Carr James C
Department of Radiology, Northwestern University, Chicago, IL, USA.
AJR Am J Roentgenol. 2008 Apr;190(4):902-6. doi: 10.2214/AJR.07.2997.
In patients with difficult i.v. access or renal insufficiency, or in those who are pregnant, we hypothesized than an unenhanced 3D segmented steady-state free precession (SSFP) MR angiography (MRA) technique would be an alternative to contrast-enhanced MR angiography (CE-MRA) for the evaluation of vasculature.
MRA examinations of the thoracic aorta were retrospectively reviewed in 23 patients in whom both CE-MRA and 3D SSFP were performed. CE-MRA was performed using an ECG-gated gradient-echo FLASH sequence. Three-dimensional SSFP MRA was performed during free breathing using a motion-adaptive navigator technique. Quantitative assessment of the 3D SSFP and CE-MRA image sets was performed by comparing the aortic lumen diameter. The quality of the images of the aortic root (scale of 1-5) and the presence of cardiovascular and noncardiovascular pathology were independently determined for both techniques by two reviewers. Bland-Altman and Wilcoxon's signed-rank analyses were performed.
The difference in orthogonal measurements of the aortic diameter between those made on images from the 3D SSFP and those made from the CE-MRA sequences was -0.042 cm. The aortic root was better visualized with 3D SSFP: score of 3.78 (of 5) for CE-MRA versus score of 4.65 (of 5) for 3D SSFP (p < 0.05).
In patients in whom contrast material is contraindicated, unenhanced MRA using a 3D SSFP technique can be performed.
对于静脉穿刺困难、肾功能不全或怀孕的患者,我们推测一种非增强三维分段稳态自由进动(SSFP)磁共振血管造影(MRA)技术可作为对比增强磁共振血管造影(CE-MRA)的替代方法用于血管系统评估。
回顾性分析23例同时行CE-MRA和三维SSFP检查的胸主动脉MRA检查结果。CE-MRA采用心电图门控梯度回波FLASH序列进行。三维SSFP MRA采用运动自适应导航技术在自由呼吸状态下进行。通过比较主动脉管腔直径对三维SSFP和CE-MRA图像集进行定量评估。由两名评估者独立确定两种技术的主动脉根部图像质量(1-5分)以及心血管和非心血管病变的存在情况。进行Bland-Altman分析和Wilcoxon符号秩分析。
三维SSFP图像与CE-MRA序列图像上主动脉直径的正交测量差值为-0.042 cm。三维SSFP对主动脉根部的显示更好:CE-MRA评分为3.78(满分5分),三维SSFP评分为4.65(满分5分)(p<0.05)。
对于禁忌使用对比剂的患者,可采用三维SSFP技术进行非增强MRA检查。