Thornton F J, Du J, Suleiman S A, Dieter R, Tefera G, Pillai K R, Korosec F R, Mistretta C A, Grist T M
Department of Radiology, University of Wisconsin, Madison, Wisconsin 53792-3252, USA.
J Magn Reson Imaging. 2006 Aug;24(2):362-70. doi: 10.1002/jmri.20630.
To evaluate a novel time-resolved contrast-enhanced (CE) projection reconstruction (PR) magnetic resonance angiography (MRA) method for identifying potential bypass graft target vessels in patients with Class II-IV peripheral vascular disease.
Twenty patients (M:F = 15:5, mean age = 58 years, range = 48-83 years), were recruited from routine MRA referrals. All imaging was performed on a 1.5 T MRI system with fast gradients (Signa LX; GE Healthcare, Waukesha, WI). Images were acquired with a novel technique that combined undersampled PR with a time-resolved acquisition to yield an MRA method with high temporal and spatial resolution. The method is called PR hyper time-resolved imaging of contrast kinetics (PR-hyperTRICKS). Quantitative and qualitative analyses were used to compare two-dimensional (2D) time-of-flight (TOF) and PR-hyperTRICKS in 13 arterial segments per lower extremity. Statistical analysis was performed with the Wilcoxon signed-rank test.
Fifteen percent (77/517) of the vessels were scored as missing or nondiagnostic with 2D TOF, but were scored as diagnostic with PR-hyperTRICKS. Image quality was superior with PR-hyperTRICKS vs. 2D TOF (on a four-point scale, mean rank = 3.3 +/- 1.2 vs. 2.9 +/- 1.2, P < 0.0001). PR-hyperTRICKS produced images with high contrast-to-noise ratios (CNR) and high spatial and temporal resolution. 2D TOF images were of inferior quality due to moderate spatial resolution, inferior CNR, greater flow-related artifacts, and absence of temporal resolution.
PR-hyperTRICKS provides superior preoperative assessment of lower limb ischemia compared to 2D TOF.
评估一种新型的时间分辨对比增强（CE）投影重建（PR）磁共振血管造影（MRA）方法，用于识别II-IV级外周血管疾病患者潜在的搭桥移植目标血管。
从常规MRA转诊患者中招募了20例患者（男:女 = 15:5，平均年龄 = 58岁，范围 = 48-83岁）。所有成像均在配备快速梯度的1.5T MRI系统（Signa LX；通用电气医疗集团，威斯康星州沃基沙）上进行。采用一种新技术采集图像，该技术将欠采样PR与时间分辨采集相结合，产生一种具有高时间和空间分辨率的MRA方法。该方法称为PR对比动力学超时间分辨成像（PR-hyperTRICKS）。使用定量和定性分析比较双下肢每个13个动脉节段的二维（2D）时间飞跃（TOF）和PR-hyperTRICKS。采用Wilcoxon符号秩检验进行统计分析。
2D TOF将15%（77/517）的血管评为缺失或无法诊断，但PR-hyperTRICKS将其评为可诊断。PR-hyperTRICKS的图像质量优于2D TOF（四分制评分，平均秩 = 3.3±1.2对2.9±1.2，P < 0.0001）。PR-hyperTRICKS产生的图像具有高对比噪声比（CNR）以及高空间和时间分辨率。2D TOF图像质量较差，原因是空间分辨率中等、CNR较低、流动相关伪影较多且缺乏时间分辨率。
与2D TOF相比，PR-hyperTRICKS能提供更好的下肢缺血术前评估。
