Introduction: Arterial spin labeling (ASL) MRI, a non-invasive perfusion imaging method, may potentially identify patients at high risk for hemorrhagic transformation (HT) by quantifying cerebral blood flow (CBF). We aimed to investigate the role of ASL MRI perfusion parameters in predicting HT and functional outcomes in acute middle cerebral artery (MCA) infarction.
Methods: A retrospective study was conducted involving 23 patients admitted within 24 hours of MCA infarction onset. Acute imaging included noncontrast cranial CT, diffusion-weighted imaging (DWI) and multiphase CT angiography. Approximately one week after symptom onset, follow-up imaging was performed with DWI and ASL MRI. Infarct volumes were manually calculated. Menon collateral scores and ASL-derived perfusion parameters, including hyperperfused area CBF and relative CBF (rCBF), were assessed. Functional outcomes were evaluated using modified Rankin Scale (mRS) at the end of 1st week, 1st month and 3rd month and Barthel Index at the end of 3rd month follow-up.
Results: HT developed in 15 patients (65.2%). HT was associated with significantly larger infarct volumes (p=0.021), lower Menon scores (p=0.006), higher rCBF values (p=0.014), and worse functional outcomes indicated by worse functional outcomes at the end of 3rd month follow-up, indicated by higher mRS scores (p=0.044) and lower Barthel Index scores (p=0.036).
Conclusion: ASL MRI parameters, particularly hyperperfused area CBF and relative CBF, along with collateral circulation and infarct volume measurements, may effectively predict the risk of HT and functional outcomes in acute MCA infarction. These parameters can enhance clinical decision-making and improve patient management strategies.
Keywords: Arterial spin labeling; hemorrhagic transformation; middle