Implementation and clinical utility of ultra-low-field portable magnetic resonance imaging for postprocedural neurological evaluation in ambulatory neurosurgery: illustrative cases.

backgroundElective endovascular neurosurgical procedures are increasingly performed in ambulatory neurosurgery centers, enabled by advances in catheter technology, safety of conscious sedation, and refined patient selection. Although complication rates are low, rapid evaluation of postprocedural neurological deficits remains critical. Conventional MRI is often impractical in outpatient or procedural settings, whereas ultra-low-field portable MRI (ULF-pMRI) systems (such as Swoop) allow bedside imaging with favorable diagnostic performance. OBSERVATIONS: Two women in their 60s developed acute neurological deficits at an ambulatory neurosurgery center (ANSC) after diagnostic cerebral angiography in one case and elective internal carotid artery flow diversion in the other. In both cases, repeat angiography showed patent vessels. Bedside ULF-pMRI with diffusion-weighted and fluid-attenuated inversion recovery sequences demonstrated no acute infarction or hemorrhage. Symptoms fully resolved with supportive management. The availability of rapid portable MRI helped both patients avoid hospital admission, allowing same-day discharge without recurrent neurological symptoms. LESSONS: In these 2 cases, ULF-pMRI demonstrated timely, informative neuroimaging in an ANSC setting. When paired with clinical improvement, bedside MRI safely guided disposition decisions, helped avoid unnecessary transfers, and supported patient safety as outpatient neurointervention expands. https://thejns.org/doi/10.3171/CASE26245.