Gopinath Ganesan, Aslam Malik, Anusha Palaniswamy
Radiology, Panimalar Medical College Hospital and Research Institute, Chennai, IND.
Radiology, Saveetha Medical College, Chennai, IND.
Cureus. 2022 Mar 29;14(3):e23625. doi: 10.7759/cureus.23625. eCollection 2022 Mar.
The role of perfusion neuroimaging in managing cases of acute ischemic stroke (AIS) is to identify ischemic penumbra and regions of hypo-perfusion, which can be salvaged. Dynamic susceptibility contrast (DSC) perfusion imaging techniques have been the main magnetic resonance imaging (MRI) perfusion techniques used to identify AIS. Arterial spin labelling (ASL) is an alternative non-invasive perfusion technique, which permits tissue perfusion measurement without any need for administration of exogenous contrast agents. The objective was to compare the diagnostic accuracy of ASL perfusion MRI versus DSC enhanced perfusion MRI in detecting perfusion-diffusion mismatch of varying volumes in acute ischemic stroke.
A hospital-based observational cross-sectional study was done in a tertiary care institute in Tamil Nadu between December 2018 to October 2019. Fifty-five subjects aged more than 18 years referred to the Radio-diagnosis department (less than 24 hours since the onset of weakness) for emergency assessment of suspected acute stroke were subjected to MRI stroke scan protocol. Then AIS cases were evaluated with ASL and DSC perfusion-weighted imaging. The collected data was entered in Excel (Microsoft, Redmond, WA, USA). IBM SPSS version 22 (IBM Corp., Armonk, NY, USA) was used for statistical analysis. Receiver operating characteristic (ROC) analysis was done to assess the predictive validity of ASL in predicting DSC mismatch. The diagnostic accuracy of ASL was the primary outcome variable. P-value < 0.05 was considered statistically significant.
Forty-four subjects confirmed as stroke were included in the final analysis. Their mean (±SD) age was 53.84 (±10.80) years. 72.7% were males. The majority (53.8%) presented during the acute stage of cerebral infarction (53.8%). The majority (45.5%) had hemiplegia followed by aphasia (27.3%). The major vascular territory involved was the middle cerebral artery (54.5%). The sensitivity, specificity, positive predictive value, and negative predictive value of ASL (non-contrast) in predicting DSC (contrast) mismatch was found to be 71.43%, 78.57%, 83.33%, and 64.71% respectively.
ASL MR has the potential to replace MRI DSC perfusion in the future imaging diagnostic work-up for stroke. However, further studies are required to validate its role as the first-line imaging for stroke therapy.
灌注神经成像在急性缺血性脑卒中（AIS）病例管理中的作用是识别可挽救的缺血半暗带和灌注减低区域。动态磁敏感对比（DSC）灌注成像技术一直是用于识别AIS的主要磁共振成像（MRI）灌注技术。动脉自旋标记（ASL）是另一种非侵入性灌注技术，无需注射外源性对比剂即可测量组织灌注。目的是比较ASL灌注MRI与DSC增强灌注MRI在检测急性缺血性脑卒中不同体积灌注-弥散不匹配方面的诊断准确性。
2018年12月至2019年10月在泰米尔纳德邦的一家三级医疗机构进行了一项基于医院的观察性横断面研究。55名年龄超过18岁（自出现肢体无力起不到24小时）因疑似急性脑卒中被转诊至放射诊断科进行紧急评估的受试者接受了MRI脑卒中扫描方案。然后对AIS病例进行ASL和DSC灌注加权成像评估。收集的数据录入Excel（美国华盛顿州雷德蒙德市微软公司）。使用IBM SPSS 22版（美国纽约州阿蒙克市IBM公司）进行统计分析。进行受试者操作特征（ROC）分析以评估ASL预测DSC不匹配的预测有效性。ASL的诊断准确性是主要结局变量。P值<0.05被认为具有统计学意义。
最终分析纳入了44名确诊为脑卒中的受试者。他们的平均（±标准差）年龄为53.84（±1）岁。72.7%为男性。大多数（53.8%）在脑梗死急性期就诊。大多数（45.5%）有偏瘫，其次是失语（27.3%）。主要累及的血管区域是大脑中动脉（54.5%）。发现ASL（非对比）预测DSC（对比）不匹配的敏感性、特异性、阳性预测值和阴性预测值分别为71.43%、78.57%、83.33%和64.71%。
ASL MR在未来脑卒中成像诊断检查中有可能取代MRI DSC灌注。然而，需要进一步研究来验证其作为脑卒中治疗一线成像的作用。
