Detecting DWI-Negative Strokes in Rat Models of Acute Internal Carotid Artery Occlusion using Magnetic Resonance Spectroscopy

It has been reported that approximately 6.8% of patients may exhibit DWI-negative results in the early phase of acute ischemic stroke (AIS). The primary reason is the reopening of obstructed vessels or compensation by collateral circulation, resulting in the rapid normalization of DWI signals. In conclusion, early DWI examination in AIS patients may lead to missed diagnoses. Therefore, it is essential to develop a method that can accurately, objectively, and effectively identify AICAO combined with AIS in the early stage, which is critical for guiding clinical decisions and improving patient outcomes. In a study by Krishna A. Dani involving 32 AIS patients, MRS detected increased lactate levels in some patients earlier than the appearance of positive DWI findings. Based on these findings, we hypothesize that MRS can detect early brain ischemia and hypoxia in AICAO combined with AIS patients and may identify AIS earlier than DWI sequences, thus guiding clinical decisions. In this study, we established a rat AICAO model and performed DWI and MRS scans at two- and twelve-hours post-modeling to evaluate whether MRS can detect early brain damage in AICAO combined with AIS more effectively than DWI.

据报道，约6.8%的急性缺血性脑卒中（Acute Ischemic Stroke, AIS）患者在发病早期可出现弥散加权成像（Diffusion Weighted Imaging, DWI）阴性结果。其主要原因为闭塞血管再通或侧支循环代偿，致使DWI信号快速恢复正常。综上，对AIS患者行早期DWI检查可能出现漏诊情况。因此，亟需开发一种能够准确、客观且高效地早期识别合并急性缺血性脑卒中的小脑前下动脉闭塞（Anterior Inferior Cerebellar Artery Occlusion, AICAO）的方法，该方法对于指导临床决策、改善患者预后至关重要。在Krishna A. Dani开展的一项纳入32例AIS患者的研究中，磁共振波谱（Magnetic Resonance Spectroscopy, MRS）可在部分患者出现DWI阳性表现之前，检测到乳酸水平升高。基于上述研究结果，本研究提出假设：MRS可检测合并AICAO的AIS患者早期脑缺血缺氧情况，且其识别AIS的时间早于DWI序列，进而为临床决策提供指导。本研究构建了大鼠AICAO模型，并于造模后2小时及12小时分别进行DWI与MRS扫描，旨在评估MRS是否较DWI更能有效检测合并AICAO的AIS患者早期脑损伤。