Wang Qi, Bie Fei, Lu Tao, Sun Xuelian, Sun Qiang, Wang Gang, Li Peiling
Department of Radiology, the Liaoning Thrombus Treatment Center of Integrated Chinese and Western Medicine, Shenyang, China.
Clinical Service Team, Philips (China) Investment Co., Ltd., Shanghai, China.
Quant Imaging Med Surg. 2023 Jun 1;13(6):3477-3488. doi: 10.21037/qims-22-991. Epub 2023 Apr 14.
In patients with acute stroke with an unknown onset time, the T2 relaxation time (qT2) in the region of diffusion restriction is associated with the time from symptom onset. We hypothesized that cerebral blood flow (CBF) status assessed using arterial spin labeling magnetic resonance (MR) imaging would influence the association between qT2 and stroke onset time. The purpose of this study was to preliminarily investigate the effects of diffusion-weighted imaging-T2-weighted fluid-attenuated inversion recovery (DWI-T2-FLAIR) mismatch and T2 mapping value changes on the accuracy of stroke onset time in patients with different CBF perfusion statuses.
A total of 94 patients with acute ischemic stroke (symptom onset time ≤24 h) admitted to the Liaoning Thrombus Treatment Center of Integrated Chinese and Western Medicine, Liaoning, China, were enrolled in this cross-sectional retrospective study. MR image compilation (MAGiC), DWI, 3-dimensional (3D) pseudo-continuous arterial spin labeling perfusion (pcASL), and T2-FLAIR images were acquired. The T2 map was directly generated from MAGiC. The CBF map was assessed using 3D pcASL. Patients were divided into the good CBF group (CBF >25 mL/100 g/min) and the poor CBF group (CBF ≤25 mL/100 g/min). The T2 relaxation time (qT2), T2 relaxation time ratio (qT2 ratio), and T2-FLAIR signal intensity ratio (T2-FLAIR ratio) between the ischemic and nonischemic region of the contralateral side were calculated. The correlations between the qT2, qT2 ratio, T2-FLAIR ratio, and stroke onset time were statistically analyzed in the different CBF groups.
In DWI-restricted areas, the time from symptom onset correlated with the qT2 and T2-FLAIR ratio. We identified an interaction between this association and CBF status. In the poor CBF group, stroke onset time most significantly correlated with the qT2 ratio (r=0.493; P<0.001), followed by the qT2 (r=0.409; P=0.001) and the T2-FLAIR ratio (r=0.385; P=0.003). In the total patient group, the stroke onset time moderately correlated with the qT2 ratio (r=0.438; P<0.001) but weakly correlated with the qT2 (r=0.314; P=0.002) and the T2-FLAIR ratio (r=0.352; P=0.001). In the good CBF group, no obvious correlations were found between stroke onset time and all MR quantitative indicators.
In patients with reduced cerebral perfusion, the stroke onset time correlated with changes in the T2-FLAIR signal and qT2. The stratified analysis showed that the qT2 ratio had a higher correlation with stroke onset time than with the qT2 and T2-FLAIR ratio.
在发病时间不明的急性卒中患者中，扩散受限区域的T2弛豫时间（qT2）与症状发作时间相关。我们推测，使用动脉自旋标记磁共振（MR）成像评估的脑血流量（CBF）状态会影响qT2与卒中发作时间之间的关联。本研究的目的是初步探讨扩散加权成像-T2加权液体衰减反转恢复（DWI-T2-FLAIR）不匹配及T2图谱值变化对不同CBF灌注状态患者卒中发作时间准确性的影响。
本横断面回顾性研究纳入了中国辽宁省中西医结合血栓病治疗中心收治的94例急性缺血性卒中患者（症状发作时间≤24小时）。采集了MR图像汇编（MAGiC）、DWI、三维（3D）伪连续动脉自旋标记灌注（pcASL）和T2-FLAIR图像。T2图谱直接由MAGiC生成。使用3D pcASL评估CBF图谱。患者分为CBF良好组（CBF>25 mL/100 g/min）和CBF不良组（CBF≤25 mL/100 g/min）。计算患侧与对侧非缺血区域之间的T2弛豫时间（qT2）、T2弛豫时间比值（qT2比值）和T2-FLAIR信号强度比值（T2-FLAIR比值）。对不同CBF组中qT2、qT2比值、T2-FLAIR比值与卒中发作时间之间的相关性进行统计学分析。
在DWI受限区域，症状发作时间与qT2和T2-FLAIR比值相关。我们发现这种关联与CBF状态之间存在相互作用。在CBF不良组中，卒中发作时间与qT2比值的相关性最为显著（r=0.493；P<0.001），其次是qT2（r=0.409；P=0.001）和T2-FLAIR比值（r=0.385；P=0.003）。在全部患者组中，卒中发作时间与qT2比值中度相关（r=0.438；P<0.001），但与qT2（r=0.314；P=0.002）和T2-FLAIR比值（r=0.352；P=0.00）的相关性较弱中。在CBF良好组中，未发现卒中发作时间与所有MR定量指标之间存在明显相关性。
在脑灌注降低的患者中，卒中发作时间与T2-FLAIR信号和qT2的变化相关。分层分析显示，qT2比值与卒中发作时间的相关性高于qT2和T2-FLAIR比值。
