Feasibility Assessment of the Wellumio 'Axana' 0.1T Portable MRI Device

Inclusion Criteria: Healthy Participants: * Adults aged 18 years or older. * Able to undergo an in-hospital MRI scan. * Able to provide informed consent. * Head size considered suitable for scanning with the Wellumio Axana brain scanner. Hospital Patients: * Adults aged 18 years or older. * Presenting to hospital with an acute neurological deficit suspected to be stroke within 24 hours of symptom onset. * Clinical and radiological diagnosis of stroke, including ischemic stroke, haemorrhagic stroke, or subarachnoid haemorrhage. * Able to undergo an in-hospital MRI scan. * Up to 72 hours post-acute stroke. * Able to provide written informed consent or, where this is not possible, informed consent provided by a legally authorised representative. * Head size considered suitable for scanning with the Wellumio Axana brain scanner. Exclusion Criteria: General: * Pregnant or breastfeeding. * Contraindication to neuroimaging, including any condition that prohibits MRI. * Presence of an implanted electro-stimulating device in the head or neck. * Presence of a large metallic craniofacial implant, such as a bone fixation plate or mesh. Small metallic objects, such as aneurysm coils, are acceptable. * Presence of an intracranial pressure monitor or another similar sensor that may compromise placement of the investigational device. * Inability to wear the investigational device, including because of scalp skin lesions or previous intracranial surgery. * Unable to lie still for the duration of the scan. * Any other condition or symptom that, in the investigator's judgement, prevents participation in the study. * Unable to provide informed consent and, where applicable, consent cannot be obtained from a legally authorised representative. Healthy Participants: * History of a neurological condition, including brain tumour, previous stroke, or neurological trauma. * Post-study MRI findings indicating a brain condition associated with structural changes.