Elevated brain oxygen extraction fraction measured by MRI susceptibility relates to perfusion status in acute ischemic stroke
Elevated brain oxygen extraction fraction measured by MRI susceptibility relates to perfusion status in acute ischemic stroke
复制标题
DOI：
10.1177/0271678x19827944
复制
发表时间：
2020-03-01
影响因子：
6.3
通讯作者：
Gauthier, Claudine J.
中科院分区：
文献类型：
--
作者：
Fan, Audrey P.;Khalil, Ahmed A.;Gauthier, Claudine J.
最近在急性缺血性卒中中进行的新血运重建疗法的临床试验强调了生理成像在确定患者最佳治疗方法方面的重要性。氧提取分数（OEF）是中风中危险组织的标志，并且可以根据静脉血中脱氧血红蛋白分子对MRI相位扫描的敏感性效应来量化。我们使用先进的定量磁敏感成像（QSM）MRI重建技术测量了20例急性脑卒中患者脑静脉内的OEF。大弥散-灌注病变不匹配患者的受累半球（29.3 +/- 3.4%）与对侧半球（25.5 +/- 3.1%）相比，绝对OEF升高（P = 0.032）。在这些患者中，OEF与动态磁敏感对比MRI测量的相对CBF呈负相关（P = 0.004），表明对血流减少的补偿。灌注-弥散匹配或无低灌注的患者两半球OEF差异较小。9例患者接受了纵向评估，基线时OEF比（受累侧与对侧）为1.2 +/- 0.1，3天后随访时恢复正常（降低）至1.0 +/- 0.1（P = 0.03）。我们的可行性研究表明，QSM MRI可以非侵入性地量化脑卒中患者的OEF，与灌注状态相关，并且对OEF随时间的变化敏感。
Recent clinical trials of new revascularization therapies in acute ischemic stroke have highlighted the importance of physiological imaging to identify optimal treatments for patients. Oxygen extraction fraction (OEF) is a hallmark of at-risk tissue in stroke, and can be quantified from the susceptibility effect of deoxyhemoglobin molecules in venous blood on MRI phase scans. We measured OEF within cerebral veins using advanced quantitative susceptibility mapping (QSM) MRI reconstructions in 20 acute stroke patients. Absolute OEF was elevated in the affected (29.3 +/- 3.4%) versus the contralateral hemisphere (25.5 +/- 3.1%) of patients with large diffusion-perfusion lesion mismatch (P = 0.032). In these patients, OEF negatively correlated with relative CBF measured by dynamic susceptibility contrast MRI (P = 0.004), suggesting compensation for reduced flow. Patients with perfusion-diffusion match or no hypo-perfusion showed less OEF difference between hemispheres. Nine patients received longitudinal assessment and showed OEF ratio (affected to contralateral) of 1.2 +/- 0.1 at baseline that normalized (decreased) to 1.0 +/- 0.1 at follow-up three days later (P = 0.03). Our feasibility study demonstrates that QSM MRI can non-invasively quantify OEF in stroke patients, relates to perfusion status, and is sensitive to OEF changes over time.