Contrast-enhanced whole-heart coronary magnetic resonance angiography at 3 T using interleaved echo planar imaging.
Contrast-enhanced whole-heart coronary magnetic resonance angiography at 3 T using interleaved echo planar imaging.
复制标题
使用交错回波平面成像进行 3 T 对比增强全心冠状动脉磁共振血管造影
DOI：
10.1097/rli.0b013e3181d8df32
复制
发表时间：
2010-08
影响因子：
6.7
通讯作者：
Li D
中科院分区：
文献类型：
--
作者：
Bhat H;Yang Q;Zuehlsdorff S;Li K;Li D
目的：本研究的目的是通过使用梯度回波交错回波平面成像（GRE-EPI）序列在3 T场强下进行对比剂增强的全心脏冠状动脉磁共振血管造影（MRA），以缩短扫描时间。材料和方法：采用GRE-EPI序列，在3 T条件下进行全心冠状动脉MRA增强扫描。一阶相位校正用于GRE-EPI回波串中奇回波和偶回波的对齐。使用体模和志愿者研究评价了用于估计线性相位校正参数的单参考和双参考扫描技术。GRE-EPI读数与并行成像相结合，以进一步减少扫描时间。为了避免图像失真，在全心脏GRE-EPI扫描之前，在单独的低分辨率GRE扫描中采集用于线圈灵敏度估计的校准信号。8名健康志愿者用优化的对比增强GRE-EPI序列扫描。GRE-EPI图像在缓慢输注（0.3 mL/s）0.1 mmol/kg体重的Gd-BOPTA期间获得。为了进行比较，在单独的扫描会话中使用传统GRE序列再次扫描相同的8名志愿者，其中相同造影剂的剂量加倍（0.2 mmol/kg体重），注射速率相同。对比增强GRE-EPI和对比增强GRE技术在相对信噪比（rSNR）、相对对比噪声比（rCNR）、图像质量评分和可视化血管长度方面进行了比较。结果：体模和志愿者研究均表明，双参考扫描相位校正技术是3 T GRE-EPI获得满意图像质量的关键步骤。GRE-EPI序列获得空间分辨率为1.0 × 1.0 × 2.0 mm 3的全冠状动脉MRA，平均扫描时间为2.5 ± 0.6 min，而GRE技术为8.6 ± 2.7 min。与GRE序列相比，GRE-EPI技术具有较低的rCNR。GRE-EPI技术的图像质量和冠状动脉可视化是足够的，并且GRE-EPI和GRE技术之间的图像质量评分、rSNR和可视化冠状动脉长度没有统计学显著差异。结论：使用GRE-EPI技术进行对比增强的全心冠状动脉MRA可出色描绘所有主要冠状动脉，与当前GRE技术相比，对比剂剂量减少2倍，扫描时间减少3倍。
Objectives:The goal of this work was to reduce the scan time of contrast-enhanced whole-heart coronary magnetic resonance angiography (MRA) by using a gradient echo interleaved echo planar imaging (GRE-EPI) sequence at 3 T field strength. Materials and Methods:A GRE-EPI sequence was optimized to acquire contrast-enhanced whole-heart coronary MRA at 3 T. First-order phase correction was used for alignment of the odd and even echoes in the GRE-EPI echo train. Single and dual reference scan techniques for estimation of the linear phase correction parameters were evaluated using both phantom and volunteer studies. The GRE-EPI readout was combined with parallel imaging for a further reduction in scan time. To avoid image distortions, calibration signals for coil sensitivity estimation were acquired in a separate low resolution GRE scan before the whole-heart GRE-EPI scan. Eight healthy volunteers were scanned with the optimized contrast-enhanced GRE-EPI sequence. GRE-EPI images were acquired during slow infusion (0.3 mL/s) of 0.1 mmol/kg body weight of Gd-BOPTA. For comparison purposes, the same 8 volunteers were scanned again in a separate scan session using a traditional GRE sequence with double the dose (0.2 mmol/kg body weight) of the same contrast agent with the same injection rate. The contrast-enhanced GRE-EPI and contrast-enhanced GRE techniques were compared in terms of relative signal-to-noise ratio (rSNR), relative contrast-to-noise ratio (rCNR), image quality scores, and visualized vessel lengths. Results:Both, phantom and volunteer studies demonstrated that the dual reference scan phase correction technique was a key step for obtaining satisfactory image quality using GRE-EPI at 3 T. Whole-heart coronary MRA with a spatial resolution of 1.0 × 1.0 × 2.0 mm3 was acquired with the GRE-EPI sequence in an average scan time of 2.5 ± 0.6 minutes, compared with 8.6 ± 2.7 minutes for the GRE technique. The GRE-EPI technique had lower rCNR compared with the GRE sequence. The image quality and coronary artery visualization with the GRE-EPI technique were adequate, and there was no statistically significant difference in the image quality scores, rSNR, and visualized coronary artery lengths between the GRE-EPI and GRE techniques. Conclusions:Contrast-enhanced whole-heart coronary MRA using the GRE-EPI technique resulted in excellent delineation of all the major coronary arteries and compared with current GRE techniques demonstrated a factor of 2 reduction in contrast agent dose and a factor of 3 reduction in scan time.