Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
Magn Reson Imaging. 2024 Oct;112:27-37. doi: 10.1016/j.mri.2024.04.009. Epub 2024 Apr 9.
Long acquisition times limit the feasibility of established non-contrast-enhanced MRA (non-CE-MRA) techniques. The purpose of this study was to evaluate a highly accelerated flow-independent sequence (Relaxation-Enhanced Angiography without Contrast and Triggering [REACT]) for imaging of the extracranial arteries in acute ischemic stroke (AIS).
Compressed SENSE (CS) accelerated (factor 7) 3D isotropic REACT (fixed scan time: 01:22 min, reconstructed voxel size 0.625 × 0.625 × 0.75 mm) and CE-MRA (CS factor 6, scan time: 1:08 min, reconstructed voxel size 0.5 mm) were acquired in 76 AIS patients (69.4 ± 14.3 years, 33 females) at 3 Tesla. Two radiologists assessed scans for the presence of internal carotid artery (ICA) stenosis and stated their diagnostic confidence using a 5-point scale (5 = excellent). Vessel quality of cervical arteries as well as the impact of artifacts and image noise were scored on 5-point scales (5 = excellent/none). Apparent signal- and contrast-to-noise ratios (aSNR/aCNR) were measured for the common carotid artery (CCA) and ICA (C1-segment).
REACT provided a sensitivity of 88.5% and specificity of 100% for clinically relevant (≥50%) ICA stenosis with substantial concordance to CE-MRA regarding stenosis grading (Cohen's kappa 0.778) and similar diagnostic confidence (REACT: mean 4.5 ± 0.4 vs. CE-MRA: 4.5 ± 0.6; P = 0.674). Presence of artifacts (3.6 ± 0.5 vs. 3.5 ± 0.7; P = 0.985) and vessel quality (all segments: 3.6 ± 0.7 vs. 3.8 ± 0.7; P = 0.004) were comparable between both techniques with REACT showing higher scores at the CCA (4.3 ± 0.6 vs. 3.8 ± 0.9; P < 0.001) and CE-MRA at V2- (3.3 ± 0.5 vs. 3.9 ± 0.8; P < 0.001) and V3-segments (3.3 ± 0.5 vs. 4.0 ± 0.8; P < 0.001). For all vessels, REACT showed a lower impact of image noise (3.8 ± 0.6 vs. 3.6 ± 0.7; P = 0.024) while yielding higher aSNR (52.5 ± 15.1 vs. 37.9 ± 12.5; P < 0.001) and aCNR (49.4 ± 15.0 vs. 34.7 ± 12.3; P < 0.001) for all vessels combined.
In patients with acute ischemic stroke, highly accelerated REACT provides an accurate detection of ICA stenosis with vessel quality and scan time comparable to CE-MRA.
传统非对比增强磁共振血管成像（non-CE-MRA）技术的采集时间较长，限制了其在临床中的应用。本研究旨在评估一种高度加速的流动无关序列（Relaxation-Enhanced Angiography without Contrast and Triggering [REACT]），用于急性缺血性脑卒中（AIS）患者颅外动脉成像。
在 3T 磁共振扫描仪上对 76 例 AIS 患者（69.4±14.3 岁，33 例女性）进行压缩传感（CS）加速（倍数 7）三维各向同性 REACT（固定扫描时间：01:22 min，重建体素大小 0.625×0.625×0.75mm）和 CE-MRA（CS 倍数 6，扫描时间：01:08 min，重建体素大小 0.5mm）扫描。两名放射科医生使用 5 分制（5=极好）评估颈内动脉（ICA）狭窄的存在，并表示他们的诊断信心。使用 5 分制（5=极好/无）对颈段动脉的血管质量以及伪影和图像噪声的影响进行评分。测量颈总动脉（CCA）和颈内动脉（C1 段）的表观信号与对比噪声比（aSNR/aCNR）。
REACT 对有临床意义的（≥50%）ICA 狭窄的敏感性为 88.5%，特异性为 100%，与 CE-MRA 相比，狭窄分级具有高度一致性（Cohen's kappa 0.778），且诊断信心相似（REACT：平均 4.5±0.4 vs. CE-MRA：4.5±0.6；P=0.674）。两种技术的伪影存在率（3.6±0.5 vs. 3.5±0.7；P=0.985）和血管质量（所有节段：3.6±0.7 vs. 3.8±0.7；P=0.004）相似，REACT 在 CCA（4.3±0.6 vs. 3.8±0.9；P<0.001）和 CE-MRA 在 V2-（3.3±0.5 vs. 3.9±0.8；P<0.001）和 V3-（3.3±0.5 vs. 4.0±0.8；P<0.001）段得分更高。对于所有血管，REACT 图像噪声的影响更小（3.8±0.6 vs. 3.6±0.7；P=0.024），而表观信号与对比噪声比（aSNR）（52.5±15.1 vs. 37.9±12.5；P<0.001）和 aCNR（49.4±15.0 vs. 34.7±12.3；P<0.001）更高。
在急性缺血性脑卒中患者中，高度加速的 REACT 能够准确检测 ICA 狭窄，其血管质量和扫描时间与 CE-MRA 相当。
