Abstract A030: Mobile Low-Field 0.23 T MRI Detects Acute Ischemic Lesions in Patients with Dizziness or Vertigo – a Prospective Cohort Study

Background: Identifying stroke patients with dizziness or vertigo is challenging because they frequently without typical stroke warning signs or symptoms. Using mobile low-field MRI in the emergency department to detect cerebral infarction(s) or hemorrhagic lesions in patients with minor ischemic stroke and TIA has not yet been thoroughly reported. Aim: We aim to assess the diagnostic capability of the ACUTA Elfin mobile low-field MRI in identifying acute ischemic stroke or hemorrhagic lesions. And we intend to analyze the factors associated with DWI positivity in these patients. Methods: This prospective observational cohort consecutively included patients presenting with dizziness/vertigo lacking focal neurological deficits who underwent mobile low-field MRI scan within 7 days of their last known well-time from the ED of a tertiary general hospital between January 2024 and April 2024. The MRI protocol included axial T1-weighted fluid-attenuated inversion recovery (FLAIR), T2-weighted FLAIR, T2-weighted fast spin-echo, hematoma -enhanced inversion recovery (HEIR), and DWI with apparent diffusion coefficient sequences within 10.5 minutes. Two raters, blinded to clinical information and CT findings, interpreted the MRI images for acute infarction and hemorrhagic lesions. Multivariable logistic regression identified predictors of DWI positivity. Variables were entered into multivariate model if they were significant at the p-value < 0.1 level in the univariate analysis. Results: A total of 887 patients (395 men and 490 women; mean [standard deviation, SD] age, 59.8 [14.7]) were enrolled. Mobile low-field MRI DWI reveals acute infarctions (Figure 1) and identified hemorrhagic lesions (Figure 2). Acute infarction prevalence differed between cohorts: 12.6% (90/715) in dizziness patients versus 14.0% (24/172) in vertigo patients. Age, higher NIHSS score, and sensory deficit predict DWI positivity in dizzy/vertigo patients. Female sex and history of coronary artery disease were negatively associated with DWI positivity in dizzy/vertigo patients (Figure 3). Conclusions: Mobile low-field MRI provides a safe, efficient, and accessible imaging solution for evaluation of patients with dizziness or vertigo in emergency settings, which detects acute infarctions and hemorrhagic lesions. This study suggests that 12.6% to 14% of patients with dizziness/vertigo without focal neurological deficits have ischemic stroke, and 1% to 2.4% were identified with hemorrhagic stroke.