Nael Kambiz, Michaely Henrik J, Villablanca Pablo, Salamon Noriko, Laub Gerhard, Finn J Paul
Department of Radiological Sciences, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095-7206, USA.
Invest Radiol. 2006 Feb;41(2):116-24. doi: 10.1097/01.rli.0000192416.19801.ca.
We sought to implement and evaluate a high-performance, extended field of view protocol for time-resolved contrast-enhanced magnetic resonance imaging (CEMRA) of the carotid circulation by using a dedicated neurovascular (NV) array coil.
A total of 16 adult volunteers and 20 clinical patients with suspected cerebrovascular disease (15 male, 21 female, 25-82 years of age) were scanned with a fast 3D MRA sequence (TR/TE: 2.16/1 milliseconds, sampling BW: 1090 Hz/pixel), with echo-sharing and parallel acquisition. All studies were performed on a 3.0 T MR system using an 8-channel neurovascular array coil. After injection of 6 mL of gadodiamide at 3 mL/s, a coronal 3D data set with in-plane resolution of 1 x 1.3 was implemented for 10 consecutive measurements each 1.8 seconds apart. The subjects subsequently underwent high spatial-resolution (in-plane: 0.8 x 0.9) CEMRA for comparative analysis. The quality of segmental arterial anatomy and the presence and degree of the arterial stenosis were evaluated by 2 neuroradiologists. The interobserver variability was tested by kappa statistics and comparative analysis between the TR-CEMRA and high spatial-resolution CEMRA was evaluated by mean of the Spearman rank correlation coefficient.
Craniocervical arteries were visualized with good image quality and definition in the diagnostic range. Occlusive disease was detected in 42 (reader A) and 44 (reader B) arterial segments with excellent interobserver agreement (kappa =0.89; 95% confidence interval 0.82-0.96). There was a significant correlation between the TR-CEMRA and high spatial-resolution CEMRA (Rs = 0.91 and 0.93, for readers A and B, respectively) for the degree of stenosis. Three aneurysms, 3 AVMs, 1 AV-fistula, and 2 subclavian steals were detected by both observers and were confirmed by correlative imaging.
Time-resolved CEMRA at 3.0 T is reliable and versatile, providing 3-dimensional time-resolved data sets with high spatial (in plane: 1.3 x 1 mm2) and temporal (1.8 seconds) resolution over a large field of view. The higher signal-to-noise ratio gain at 3.0 T can be used effectively to improve performance of fast imaging and to support aggressive parallel acquisition protocols, as in the present study. Further clinical studies are required to establish the range of applications and the accuracy of the technique.
我们试图通过使用专用的神经血管（NV）阵列线圈，为颈动脉循环的时间分辨对比增强磁共振成像（CEMRA）实施并评估一种高性能、扩展视野协议。
共有16名成年志愿者和20名疑似脑血管疾病的临床患者（15名男性，21名女性，年龄25 - 82岁）接受了快速3D MRA序列扫描（TR/TE：2.16/1毫秒，采样带宽：1090 Hz/像素），采用回波共享和平行采集。所有研究均在3.0 T MR系统上使用8通道神经血管阵列线圈进行。以3 mL/s的速度注射6 mL钆双胺后，实施具有1×1.3平面分辨率的冠状3D数据集，每隔1.8秒连续测量10次。受试者随后接受高空间分辨率（平面：0.8×0.9）的CEMRA进行对比分析。由2名神经放射科医生评估节段性动脉解剖结构的质量以及动脉狭窄的存在情况和程度。通过kappa统计检验观察者间的变异性，并通过Spearman等级相关系数的均值评估TR-CEMRA与高空间分辨率CEMRA之间的对比分析。
在诊断范围内，颅颈动脉以良好的图像质量和清晰度显示。在42个（读者A）和44个（读者B）动脉节段中检测到闭塞性疾病，观察者间一致性极佳（kappa = 0.89；95%置信区间0.82 - 0.96）。对于狭窄程度，TR-CEMRA与高空间分辨率CEMRA之间存在显著相关性（读者A和B的Rs分别为0.91和0.93）。两位观察者均检测到3个动脉瘤、3个动静脉畸形、1个动静脉瘘和2个锁骨下窃血，并通过相关成像得到证实。
3.0 T的时间分辨CEMRA可靠且通用，可在大视野范围内提供具有高空间（平面：1.3×1 mm2）和时间（1.8秒）分辨率的三维时间分辨数据集。如本研究中所示，3.0 T时更高的信噪比增益可有效用于提高快速成像的性能并支持积极的并行采集协议。需要进一步的临床研究来确定该技术的应用范围和准确性。
