Perfusion Hyperintensities in Patients With Seizures: Evaluation With Arterial Spin Labeling Magnetic Resonance Imaging Within 24 Hours After Onset

Abstract

Purpose: We used arterial spin labeling (ASL) perfusion magnetic resonance (MR) imaging to evaluate cerebral perfusion abnormalities in patients with seizures within 24 hours of symptom onset. Materials and Methods: A retrospective search of our institutional database identified 27 patients who had undergone ASL perfusion studies for seizures or seizure-like symptoms. The inclusion criteria were as follows: 1) history of seizure, 2) MR examination performed within 24 hour of seizure onset, and 3) localized perfusion abnormality on ASL. We evaluated the presence, location, and extent of perfusion abnormalities on ASL and signal abnormalities on fluid-attenuated inversion recovery (FLAIR), diffusion-weighted image (DWI), and susceptibility-weighted image (SWI), respectively. All pathological MR findings, accompanying focal neurological symptoms, and electroencephalogram (EEG) findings were compared. Results: The mean time from symptom onset to MR examination was 5 h 54 min. All patients (n = 27) showed localized increased perfusion on ASL perfusion imaging. On FLAIR imaging, 20 patients (74.1%) showed hyperintensity in the area of perfusion abnormality. In 19 patients (70.4%), DWI showed hyperintensity of the lesion with decreased apparent diffusion coefficient value (ADC). Seven patients (25.9%) showed a focal parenchymal area of pseudo-narrowed cortical veins on SWI, associated with focal hyperperfusion. In 20 patients (74.1%), the extent of perfusion abnormalities on ASL was greater than that of signal abnormalities on FLAIR or DWI. In 14/16 patients (87.5%) with abnormal EEG findings, the area with EEG findings and the location of the hyperperfusion abnormality on ASL corresponded. Conclusion: In patients with seizures within 24 hours of symptom onset, ASL perfusion imaging revealed localized hyperperfusion, which was more frequent than signal intensity abnormalities on FLAIR or DWI. The locations of hyperperfusion areas correlated with EEG abnormalities. Thus, the ASL sequence may be a useful clinical assessment protocol for evaluating patients with seizures. © 2024 Korean Society of Magnetic Resonance in Medicine.