Kashiwazaki Daina, Yamamoto Shusuke, Hori Emiko, Akioka Naoki, Noguchi Kyo, Kuroda Satoshi
Department of Neurosurgery, University of Toyama, Toyama, Japan.
Department of Radiology, University of Toyama, Toyama, Japan.
Surg Neurol Int. 2024 Sep 6;15:322. doi: 10.25259/SNI_571_2024. eCollection 2024.
Transient fluid-attenuated inversion recovery (FLAIR) hyperintensity is often observed on the operated brain surface after direct or combined bypass surgery for moyamoya disease, but its pathophysiology and clinical significance are still obscure. This study was aimed to clarify the underlying mechanism and clinical significance.
This prospective study included 106 hemispheres of 61 patients with moyamoya disease and analyzed their radiological findings before and after combined bypass surgery. This study also included 11 patients who underwent superficial temporal artery to middle cerebral artery anastomosis for occlusive carotid artery diseases as the controls. Magnetic resonance imaging examination was serially repeated, and cerebral blood flow was measured before and after surgery. Signal intensity ratio (SIR) in the cortical sulci and cortex to the adjacent white matter on FLAIR images was calculated, and the postoperative SIR changes were semi-quantitatively evaluated to assess the temporal profile of postoperative FLAIR hyperintensity.
Postoperative FLAIR hyperintensity occurred within the cortical sulci on the operated hemispheres in all moyamoya patients but not in patients with occlusive carotid artery diseases. SIR values started to increase immediately after surgery, peaked at about 4-fold at 4-13 days post-surgery, then declined, and recovered to baseline values over 28 days or later. The magnitude of this phenomenon was proportional to the severity of cerebral ischemia but not to postoperative hyperperfusion.
Reversible sulcal FLAIR hyperintensity specifically occurs in the operated hemispheres after direct bypass surgery for moyamoya disease. This "" may represent the mixture of the extensive leakage of oxygen and proteins from the pial arteries into the CSF.
在烟雾病直接或联合搭桥手术后，常在手术侧脑表面观察到短暂的液体衰减反转恢复（FLAIR）高信号，但 其病理生理学和临床意义仍不明确。本研究旨在阐明其潜在机制和临床意义。
这项前瞻性研究纳入了61例烟雾病患者的106个半球，并分析了联合搭桥手术前后的影像学表现。本研究还纳入了11例因颈动脉闭塞性疾病行颞浅动脉-大脑中动脉吻合术的患者作为对照。连续重复进行磁共振成像检查，并在手术前后测量脑血流量。计算FLAIR图像上皮质沟回和皮质与相邻白质的信号强度比（SIR），并对术后SIR变化进行半定量评估，以评估术后FLAIR高信号的时间变化情况。
所有烟雾病患者手术侧半球的皮质沟回内均出现术后FLAIR高信号，而颈动脉闭塞性疾病患者未出现。SIR值在术后立即开始升高，在术后4 - 13天达到约4倍的峰值，然后下降，并在28天或更晚恢复到基线值。这种现象的程度与脑缺血的严重程度成正比，而与术后高灌注无关。
烟雾病直接搭桥手术后，手术侧半球特异性地出现可逆性脑沟FLAIR高信号。这“可能代表软脑膜动脉中氧和蛋白质大量漏入脑脊液的混合情况”。 （注：原文中双引号部分内容似乎不完整，翻译时保留原样）
