From the Departments of Medical Imaging (K.N., R.K., G.C., A.M., C.S.K.) and Neurology (J.T., K.D., B.M.C., C.S.K.), University of Arizona, Tucson; and Department of Radiological Sciences, University of California, Los Angeles (P.V.).
Stroke. 2014 Jul;45(7):1985-91. doi: 10.1161/STROKEAHA.114.005305. Epub 2014 Jun 10.
If magnetic resonance imaging (MRI) is to compete with computed tomography for evaluation of patients with acute ischemic stroke, there is a need for further improvements in acquisition speed.
Inclusion criteria for this prospective, single institutional study were symptoms of acute ischemic stroke within 24 hours onset, National Institutes of Health Stroke Scale ≥3, and absence of MRI contraindications. A combination of echo-planar imaging (EPI) and a parallel acquisition technique were used on a 3T magnetic resonance (MR) scanner to accelerate the acquisition time. Image analysis was performed independently by 2 neuroradiologists.
A total of 62 patients met inclusion criteria. A repeat MRI scan was performed in 22 patients resulting in a total of 84 MRIs available for analysis. Diagnostic image quality was achieved in 100% of diffusion-weighted imaging, 100% EPI-fluid attenuation inversion recovery imaging, 98% EPI-gradient recalled echo, 90% neck MR angiography and 96% of brain MR angiography, and 94% of dynamic susceptibility contrast perfusion scans with interobserver agreements (k) ranging from 0.64 to 0.84. Fifty-nine patients (95%) had acute infarction. There was good interobserver agreement for EPI-fluid attenuation inversion recovery imaging findings (k=0.78; 95% confidence interval, 0.66-0.87) and for detection of mismatch classification using dynamic susceptibility contrast-Tmax (k=0.92; 95% confidence interval, 0.87-0.94). Thirteen acute intracranial hemorrhages were detected on EPI-gradient recalled echo by both observers. A total of 68 and 72 segmental arterial stenoses were detected on contrast-enhanced MR angiography of the neck and brain with k=0.93, 95% confidence interval, 0.84 to 0.96 and 0.87, 95% confidence interval, 0.80 to 0.90, respectively.
A 6-minute multimodal MR protocol with good diagnostic quality is feasible for the evaluation of patients with acute ischemic stroke and can result in significant reduction in scan time rivaling that of the multimodal computed tomographic protocol.
如果磁共振成像（MRI）要在评估急性缺血性脑卒中患者方面与计算机断层扫描（CT）竞争，那么就需要进一步提高采集速度。
本前瞻性、单中心研究的纳入标准为发病 24 小时内出现急性缺血性脑卒中症状、美国国立卫生研究院卒中量表（NIHSS）评分≥3 分、无 MRI 禁忌证。在 3T 磁共振（MR）扫描仪上采用平面回波成像（EPI）和并行采集技术来加速采集时间。由 2 名神经放射科医生独立进行图像分析。
共有 62 例患者符合纳入标准。22 例患者进行了重复 MRI 扫描，总共可对 84 例 MRI 进行分析。弥散加权成像、EPI 液体衰减反转恢复成像、EPI 梯度回波、颈部 MR 血管造影和脑 MR 血管造影的诊断图像质量均达到 100%，动态磁敏感对比灌注扫描的图像质量达到 96%，观察者间一致性（k）范围为 0.64 至 0.84。59 例（95%）患者有急性梗死。EPI 液体衰减反转恢复成像表现的观察者间一致性良好（k=0.78；95%置信区间，0.66-0.87），使用动态磁敏感对比-Tmax 检测不匹配分类的一致性也很好（k=0.92；95%置信区间，0.87-0.94）。两名观察者均在 EPI 梯度回波上检测到 13 例急性颅内出血。颈、脑对比增强 MR 血管造影分别检出 68 处和 72 处节段性动脉狭窄，观察者间一致性 k 值分别为 0.93（95%置信区间，0.84 至 0.96）和 0.87（95%置信区间，0.80 至 0.90）。
一种 6 分钟多模态 MR 方案具有良好的诊断质量，可用于评估急性缺血性脑卒中患者，并且可以显著减少扫描时间，与多模态 CT 方案相媲美。
