Park Min-Gyu, Yang Tae-Il, Oh Se-Jin, Baik Seung Kug, Kang Yang Ho, Park Kyung-Pil
Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea.
Cerebrovasc Dis. 2014;38(4):254-61. doi: 10.1159/000367709. Epub 2014 Nov 13.
Multiple hypointense vessels (MHV) on susceptibility-weighted imaging (SWI) are frequently observed in patients with acute cerebral ischemia, but their implication has not been clearly established. To elucidate the clinical significance of MHV on SWI, we investigated the association of MHV on SWI with clinical data and other MR markers in patients with acute ischemic stroke.
We enrolled acute stroke patients with internal carotid or proximal middle cerebral artery occlusion who underwent MRI including SWI within 3 days from stroke onset. Baseline clinical data were reviewed. Stroke severity was measured by the National Institutes of Health Stroke Scale (NIHSS). We graded the degree of MHV on SWI as four groups of none, subtle, relative, or extensive by the modified Alberta Stroke Program Early CT Scan (ASPECTS) system. To evaluate the degree of collateral flow, distal hyperintense vessels (DHV) on FLAIR and vessels on post-contrast time-of-flight MR angiography (TOF MRA) source images were graded respectively as 3 groups: none/subtle/prominent and poor/moderate/good. Diffusion and perfusion lesion volume and diffusion-perfusion mismatch (DPM) ratio were measured in all patients. We analyzed the association of the degree of MHV on SWI with clinical data and MR markers.
Eighty patients were included in the study. The mean MR time from stroke onset was 12.4 h (range 0.5-63.0). There is no difference in MR time from stroke onset between groups of MHV on SWI. MHV were observed in 68 (85%) of 80 patients: none in 12, subtle in 11, relative in 13, and extensive in 44. There were no statistically significant associations between MHV on SWI and vascular risk factors. Patients with more extensive MHV on SWI had a smaller diffusion volume (p < 0.001), larger DPM (p < 0.001), and lower initial NIHSS scores (p = 0.022). Prominent DHV was presented in 29 of 44 patients with extensive MHV (p < 0.001). Good collateral flow on TOF MRA source images was presented in 37 of 44 patients with extensive MHV (p < 0.001).
More extensive MHV on SWI in acute ischemic stroke is associated with lower initial NIHSS scores, smaller diffusion lesion volume, better collateral flow, and larger DPM. Our results show the possibility that MHV on SWI may be a useful surrogate marker for predicting increased oxygen extraction fraction and diffusion-perfusion mismatch in acute ischemic hemisphere.
在急性脑缺血患者的磁敏感加权成像（SWI）上经常观察到多发低信号血管（MHV），但其意义尚未明确。为阐明SWI上MHV的临床意义，我们研究了急性缺血性卒中患者SWI上的MHV与临床资料及其他磁共振成像（MR）标志物之间的关联。
我们纳入了发病3天内接受包括SWI在内的MRI检查的颈内动脉或大脑中动脉近端闭塞的急性卒中患者。回顾基线临床资料。采用美国国立卫生研究院卒中量表（NIHSS）评估卒中严重程度。我们根据改良的阿尔伯塔卒中项目早期CT扫描（ASPECTS）系统将SWI上的MHV程度分为无、轻微、相对或广泛四组。为评估侧支血流程度，分别将液体衰减反转恢复序列（FLAIR）上的远端高信号血管（DHV）和对比剂增强磁共振血管造影（TOF MRA）源图像上的血管分为无/轻微/显著和差/中/好三组。测量所有患者的扩散和灌注病变体积以及扩散-灌注不匹配（DPM）比率。我们分析了SWI上MHV程度与临床资料及MR标志物之间的关联。
80例患者纳入研究。卒中发作至MR检查的平均时间为12.4小时（范围0.5 - 63.0小时）。SWI上MHV分组之间卒中发作至MR检查的时间无差异。80例患者中有68例（85%）观察到MHV：无MHV的12例，轻微MHV的11例，相对MHV的13例，广泛MHV的44例。SWI上的MHV与血管危险因素之间无统计学显著关联。SWI上MHV更广泛的患者扩散体积较小（p < 0.001），DPM较大（p < 0.001），初始NIHSS评分较低（p = 0.022）。44例广泛MHV患者中有29例出现显著的DHV（p < 0.001）。44例广泛MHV患者中有37例在TOF MRA源图像上显示良好的侧支血流（p < 0.001）。
急性缺血性卒中患者SWI上更广泛的MHV与较低的初始NIHSS评分、较小的扩散病变体积、较好的侧支血流和较大的DPM相关。我们的结果表明，SWI上的MHV有可能成为预测急性缺血半球氧摄取分数增加和扩散-灌注不匹配的有用替代标志物。
