Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China.
Department of Radiology, University of Washington, Seattle, Washington, USA.
J Magn Reson Imaging. 2017 Oct;46(4):1045-1052. doi: 10.1002/jmri.25653. Epub 2017 Feb 6.
To evaluate in a proof-of-concept study the feasibility of Simultaneous Noncontrast Angiography and intraPlaque hemorrhage (SNAP) imaging as a clinical magnetic resonance angiography (MRA) technique for measuring carotid stenosis. There is a growing interest in detecting intraplaque hemorrhage (IPH) during the clinical management of carotid disease, yet luminal stenosis has remained indispensable during clinical decision-making. SNAP imaging has been proposed as a novel IPH imaging technique that provides carotid MRA with no added scan time. Flowing blood shows negative signal on SNAP because of phase-sensitive inversion recovery.
In all, 58 asymptomatic subjects with 16-79% stenosis on ultrasound were scanned at 3T by SNAP with 0.8 mm isotropic resolution and 16 cm longitudinal coverage. Two readers measured luminal stenosis of bilateral carotid arteries (n = 116) on minimum intensity projections of SNAP using the NASCET criteria. In the subset (48 arteries) with contrast-enhanced (CE) MRA available for comparison, luminal stenosis was also measured on maximum intensity projections of CE-MRA.
Intraclass correlation coefficients (ICCs) with 95% confidence intervals were 0.94 (0.90-0.96) and 0.93 (0.88-0.96) for intra- and interreader agreement on stenosis measurements, respectively. Corresponding kappas for grading stenosis (0-29%, 30-69%, 70-99%, and 100%) were 0.79 (0.67-0.89) and 0.80 (0.68-0.90). Agreement between SNAP and CE-MRA was high (ICC: 0.95 [0.90-0.98]; kappa: 0.82 [0.71-0.93]).
As a dedicated IPH-imaging sequence, SNAP also provided carotid stenosis measurement that showed high intra- and interreader consistency and excellent agreement with CE-MRA. Further comparisons with digital subtraction angiography and other noninvasive techniques are warranted.
2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1045-1052.
在一项概念验证研究中评估 Simultaneous Noncontrast Angiography 和 intraPlaque hemorrhage（SNAP）成像作为一种临床磁共振血管造影（MRA）技术用于测量颈动脉狭窄的可行性。在颈动脉疾病的临床管理中，检测斑块内出血（IPH）的兴趣日益浓厚，但在临床决策中仍然需要管腔狭窄。SNAP 成像已被提议作为一种新的 IPH 成像技术，可为颈动脉 MRA 提供无额外扫描时间。由于相位敏感反转恢复，流动血液在 SNAP 上显示负信号。
共有 58 名无症状受试者，超声显示狭窄程度为 16%-79%，在 3T 上进行 SNAP 扫描，具有 0.8mm 各向同性分辨率和 16cm 纵向覆盖范围。两位读者使用 NASCET 标准在 SNAP 的最小强度投影上测量双侧颈动脉的管腔狭窄（n=116）。在具有对比增强（CE）MRA 可供比较的亚组（48 个动脉）中，也在 CE-MRA 的最大强度投影上测量管腔狭窄。
狭窄程度测量的组内和组间一致性的 intraclass 相关系数（ICC）分别为 0.94（0.90-0.96）和 0.93（0.88-0.96）。分级狭窄（0-29%、30-69%、70-99%和 100%）的相应kappa 值为 0.79（0.67-0.89）和 0.80（0.68-0.90）。SNAP 与 CE-MRA 之间的一致性很高（ICC：0.95[0.90-0.98]；kappa：0.82[0.71-0.93]）。
作为一种专用的 IPH 成像序列，SNAP 还提供了颈动脉狭窄测量，具有高的组内和组间一致性，并与 CE-MRA 具有极好的一致性。需要与数字减影血管造影和其他非侵入性技术进行进一步比较。
2 技术功效：第 2 阶段 J. Magn. Reson. Imaging 2017;46:1045-1052.
