Department of Radiology, Stanford University, Stanford, CA, USA.
Department of Neuroradiology, Hospital Beatriz Ângelo, Loures, Lisbon, Portugal.
J Cereb Blood Flow Metab. 2023 Nov;43(2_suppl):138-151. doi: 10.1177/0271678X221140343. Epub 2022 Nov 20.
Cerebrovascular reserve (CVR) reflects the capacity of cerebral blood flow (CBF) to change. Decreased CVR implies poor hemodynamics and is linked to a higher risk for stroke. Revascularization has been shown to improve CBF in patients with vasculopathy such as Moyamoya disease. Dynamic susceptibility contrast (DSC) can measure transit time to evaluate patients suspected of stroke. Arterial spin labeling (ASL) is a non-invasive technique for CBF, CVR, and arterial transit time (ATT) measurements. Here, we investigate the change in hemodynamics 4-12 months after extracranial-to-intracranial direct bypass in 52 Moyamoya patients using ASL with single and multiple post-labeling delays (PLD). Images were collected using ASL and DSC with acetazolamide. CVR, CBF, ATT, and time-to-maximum (Tmax) were measured in different flow territories. Results showed that hemodynamics improved significantly in regions affected by arterial occlusions after revascularization. CVR increased by 16 ± 11% (p < 0.01) and 25 ± 13% (p < 0.01) for single- and multi-PLD ASL, respectively. Transit time measured by multi-PLD ASL and post-vasodilation DSC reduced by 13 ± 7% (p < 0.01) and 9 ± 5% (p < 0.01), respectively. For all regions, ATT correlated significantly with Tmax (R = 0.59, p < 0.01). Thus, revascularization improved CVR and decreased transit times. Multi-PLD ASL can serve as an effective and non-invasive modality to examine vascular hemodynamics in Moyamoya patients.
脑血管储备能力(CVR)反映了脑血流(CBF)改变的能力。CVR 降低意味着血液动力学不佳,与中风风险增加有关。血管病变患者(如烟雾病)的再血管化已被证明可以改善 CBF。动态对比增强磁共振(DSC)可以测量通过时间来评估疑似中风的患者。动脉自旋标记(ASL)是一种用于 CBF、CVR 和动脉通过时间(ATT)测量的非侵入性技术。在这里,我们使用 ASL 与单和多后标记延迟(PLD)研究了 52 例烟雾病患者颅外到颅内直接旁路手术后 4-12 个月的血液动力学变化。使用 ASL 和乙酰唑胺收集 DSC 图像。在不同的血流区域测量 CVR、CBF、ATT 和达峰时间(Tmax)。结果表明,再血管化后动脉闭塞影响区域的血液动力学明显改善。单 PLD ASL 和多 PLD ASL 的 CVR 分别增加了 16±11%(p<0.01)和 25±13%(p<0.01)。多 PLD ASL 测量的通过时间和血管扩张后的 DSC 减少了 13±7%(p<0.01)和 9±5%(p<0.01)。对于所有区域,ATT 与 Tmax 显著相关(R=0.59,p<0.01)。因此,再血管化可提高 CVR 并降低通过时间。多 PLD ASL 可作为一种有效、非侵入性的方法,用于检查烟雾病患者的血管血液动力学。