Donnan, Geoffrey A.

Background Rapid stroke type identification is essential for time‐sensitive interventions, yet timely neuroimaging remains limited, especially in pre‐hospital and resource‐constrained settings. The EMVision emu™ Brain Scanner is a portable neurodiagnostic device using non‐ionizing electromagnetic signals to distinguish stroke subtypes. In an Australian prevalidation study enrolling 277 suspected stroke patients, it demonstrated diagnostic accuracy with sensitivity and specificity of 92% and 85% for hemorrhagic and 95% and 80% for ischemic strokes, respectively. Case studies and image reconstructions provided (figures 1 and 2). This follow‐up study aims to validate the diagnostic performance of emu™ for detecting intracranial hemorrhage in an international cohort, targeting ≥80% sensitivity and specificity. Methods A prospective, multi‐center, international, paired diagnostic accuracy study, with 4 US sites and 2 Australian sites. It will enroll 300 patients presenting within 12 hours of stroke onset. Patients will be stratified into two arms: intracranial hemorrhage, and ischemic stroke, TIA, or stroke mimic. Participants will undergo standard imaging, followed by non‐invasive scan by the emu™ device. Ground‐truth diagnoses will be adjudicated by a blinded expert panel. The primary endpoints are the sensitivity and specificity of the emu™ device for detecting hemorrhage, calculated against the reference standard. Statistical inference will rely on whether the lower bound of the 95% confidence interval for sensitivity and specificity exceeds 80%. Results First Australian and US enrollments occurred on June 11, 2025, and July 3, 2025, respectively. Latest progress in the study will be presented at the time of conference. Conclusion This is the first international validation study of a portable electromagnetic brain scanner for intracranial hemorrhage detection; a novel, non‐ionizing, diagnostic tool that can revolutionize acute stroke triage, enabling earlier treatment decisions, improved workflows, and equitable access to neuroimaging. image image

Background The recommended maximum age and time window for intravenous alteplase treatment of acute ischemic stroke differs between the Europe Union and United States. Aims We compared the effects of alteplase in cohorts defined by the current Europe Union or United States marketing approval labels, and by hypothetical revisions of the labels that would remove the Europe Union upper age limit or extend the United States treatment time window to 4.5 h. Methods We assessed outcomes in an individual-patient-data meta-analysis of eight randomized trials of intravenous alteplase (0.9 mg/kg) versus control for acute ischemic stroke. Outcomes included: excellent outcome (modified Rankin score 0–1) at 3–6 months, the distribution of modified Rankin score, symptomatic intracerebral hemorrhage, and 90-day mortality. Results Alteplase increased the odds of modified Rankin score 0–1 among 2449/6136 (40%) patients who met the current European Union label and 3491 (57%) patients who met the age-revised label (odds ratio 1.42, 95% CI 1.21−1.68 and 1.43, 1.23−1.65, respectively), but not in those outside the age-revised label (1.06, 0.90−1.26). By 90 days, there was no increased mortality in the current and age-revised cohorts (hazard ratios 0.98, 95% CI 0.76−1.25 and 1.01, 0.86–1.19, respectively) but mortality remained higher outside the age-revised label (1.19, 0.99–1.42). Similarly, alteplase increased the odds of modified Rankin score 0-1 among 1174/6136 (19%) patients who met the current US approval and 3326 (54%) who met a 4.5-h revised approval (odds ratio 1.55, 1.19−2.01 and 1.37, 1.17−1.59, respectively), but not for those outside the 4.5-h revised approval (1.14, 0.97−1.34). By 90 days, no increased mortality remained for the current and 4.5-h revised label cohorts (hazard ratios 0.99, 0.77−1.26 and 1.02, 0.87–1.20, respectively) but mortality remained higher outside the 4.5-h revised approval (1.17, 0.98–1.41). Conclusions An age-revised European Union label or 4.5-h-revised United States label would each increase the number of patients deriving net benefit from alteplase by 90 days after acute ischemic stroke, without excess mortality.

The recent “Advanced Neuroimaging for Acute Stroke Treatment” meeting on September 7 and 8, 2007 in Washington DC, brought together stroke neurologists, neuroradiologists, emergency physicians, neuroimaging research scientists, members of the National Institute of Neurological Disorders and Stroke (NINDS), the National Institute of Biomedical Imaging and Bioengineering (NIBIB), industry representatives, and members of the US Food and Drug Administration (FDA) to discuss the role of advanced neuroimaging in acute stroke treatment. The goals of the meeting were to assess state-of-the-art practice in terms of acute stroke imaging research and to propose specific recommendations regarding: (1) the standardization of perfusion and penumbral imaging techniques, (2) the validation of the accuracy and clinical utility of imaging markers of the ischemic penumbra, (3) the validation of imaging biomarkers relevant to clinical outcomes, and (4) the creation of a central repository to achieve these goals. The present article summarizes these recommendations and examines practical steps to achieve them.