Uwano Ikuko, Kameda Hiroyuki, Harada Taisuke, Kobayashi Masakazu, Yanagihara Wataru, Setta Kengo, Ogasawara Kuniaki, Yoshioka Kunihiro, Yamashita Fumio, Mori Futoshi, Matsuda Tsuyoshi, Sasaki Makoto
Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate, Japan.
Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
J Stroke Cerebrovasc Dis. 2020 Sep;29(9):105081. doi: 10.1016/j.jstrokecerebrovasdis.2020.105081. Epub 2020 Jul 2.
Cerebrovascular reactivity (CVR) to acetazolamide (ACZ) on single-photon emission computed tomography (SPECT) can be used to assess the severity of chronic cerebral ischemia; however, this is an invasive method. We examined whether whole-brain magnetic resonance angiography (MRA) at 7T could non-invasively detect impaired CVR in patients with chronic cerebral ischemia by demonstrating the leptomeningeal collaterals (LMCs).
Fifty-seven patients with symptomatic unilateral cervical stenosis underwent whole-brain time-of-flight MRA at 7T and cerebral perfusion SPECT before/after the ACZ challenge. MRA images were visually assessed based on 6-point grading systems to evaluate the development of LMCs toward the middle cerebral artery (MCA) and antegrade flow of MCA. CVR of the affected side was calculated from the SPECT data. Subsequently, we compared the LMC grades on MRA with CVR on SPECT.
CVR was significantly lower in grades ≥ 2 of LMCs than in grades 0-1 (P < 0.05) when applying LMCs from the anterior cerebral artery (ACA) and/or posterior cerebral artery (PCA). These differences were more evident than those in the grading of the antegrade MCA flow. The LMC grades from ACA/PCA readily detected reduced CVR (< 18.4%) with a sensitivity/specificity of 0.79/0.82.
The development of LMCs on whole-brain MRA at 7T can non-invasively detect reduced CVR with a high sensitivity/specificity in patients with unilateral cervical stenosis.
单光子发射计算机断层扫描（SPECT）上乙酰唑胺（ACZ）激发试验的脑血管反应性（CVR）可用于评估慢性脑缺血的严重程度；然而，这是一种侵入性方法。我们研究了7T全脑磁共振血管造影（MRA）能否通过显示软脑膜侧支循环（LMCs）来无创检测慢性脑缺血患者受损的CVR。
57例有症状的单侧颈内动脉狭窄患者在ACZ激发试验前后接受了7T全脑时间飞跃MRA和脑灌注SPECT检查。基于6分评分系统对MRA图像进行视觉评估，以评估向大脑中动脉（MCA）的LMCs发育情况和MCA的正向血流。根据SPECT数据计算患侧的CVR。随后，我们比较了MRA上的LMC等级与SPECT上的CVR。
当应用来自大脑前动脉（ACA）和/或大脑后动脉（PCA）的LMCs时，LMCs≥2级的CVR显著低于0-1级（P<0.05）。这些差异比MCA正向血流分级中的差异更明显。来自ACA/PCA的LMC等级能够以0.79/0.82的敏感性/特异性轻松检测到降低的CVR（<18.4%）。
7T全脑MRA上LMCs的发育能够以高敏感性/特异性无创检测单侧颈内动脉狭窄患者降低的CVR。
