ABSTRACT NUMBER: ESOC2026A2238 PORTABLE ULTRA LOW-FIELD MRI FOR BEDSIDE EVALUATION OF SUSPECTED STROKE

Abstract Background and aims Timely neuroimaging is essential in suspected acute ischemic stroke. CT is typically first-line, while MRI is required when CT is negative or inconclusive and clinical suspicion persists. Limited access to conventional high-field MRI (cMRI) may delay diagnosis. Portable ultra low-field MRI (pMRI) allows bedside imaging and may support imaging triage. This study evaluates the feasibility and diagnostic performance of bedside pMRI in a stroke unit. Methods This ongoing prospective observational study includes adult inpatients with suspected stroke, negative or inconclusive initial CT, and a planned cMRI. Bedside pMRI was performed in the stroke unit using a 0.064 T Hyperfine Swoop MR system (Hyperfine Inc, CT, US; software version 9.0). The protocol included axial DWI (b = 0/900), T2-FLAIR, and axial and coronal T2-weighted sequences. pMRI findings were visually compared with cMRI for lesion detection, agreement, and artefacts. Results Twenty-five patients have been examined. Thirteen had acute ischemic lesions on cMRI. Eleven were correctly identified on pMRI, although some small punctate components were not visualized. Two lesions were missed on pMRI: a) a <2 mm hippocampal lesion in a TGA-patient, and b) an 8 mm thalamic lesion. All twelve patients with negative cMRI findings were also negative on pMRI. Overall agreement between pMRI and cMRI was high for clinically relevant lesions. Conclusions Bedside pMRI is feasible in the stroke unit and shows good concordance with cMRI in suspected stroke. pMRI may complement existing workflows and improve imaging triage; however, negative pMRI findings should not preclude further imaging when clinical suspicion remains high. Conflict of interest Maja Möllerström: nothing to disclose; Hugo Delvéus: nothing to disclose; Dereje Wondim: nothing to disclose; Irina Dragancea: nothing to disclose; Khaled Sayah: nothing to disclose; Emelie Lind: nothing to disclose; Faramarz Vahedi: nothing to disclose; Björn Hansen: nothing to disclose; Pia Sundgren: nothing to disclose; Finn Lennartsson: nothing to disclose