CT Matches MRI for Acute Basilar Artery Occlusion Imaging

In the high-stakes environment of acute stroke care, every second counts as medical teams race to restore blood flow to the brain. For patients suffering from acute basilar artery occlusion, a particularly severe form of stroke affecting the brainstem, the choice of initial imaging modality has long been a subject of intense clinical debate. While magnetic resonance imaging offers superior soft-tissue contrast and detailed assessment of brain tissue viability, computed tomography is widely available, faster, and less susceptible to motion artifacts. A new post hoc analysis of the ATTENTION trial, published in the Journal of Neurology, provides compelling evidence that the initial imaging choice between MRI and CT does not significantly impact patient outcomes or treatment workflow efficiency.

The study, led by researchers including Feiyang Gao and Wei Hu, examined data from 340 patients who participated in the ATTENTION trial, a landmark study evaluating endovascular treatment for acute basilar artery occlusion. In this post hoc analysis, patients were categorized into two groups based on the imaging modality used for their baseline evaluation: 277 patients underwent computed tomography, while 63 patients received magnetic resonance imaging. The primary objective was to determine whether the choice of imaging modality influenced the likelihood of achieving a favorable functional outcome, defined as a modified Rankin Scale score of 0 to 3 at 90 days.

The results indicated that baseline imaging modality was not significantly associated with the primary outcome in the overall cohort. The odds ratio for achieving a modified Rankin Scale score of 0 to 3 was 0.99, with a 95% confidence interval ranging from 0.50 to 1.95, and a p-value of 0.976. This statistical finding suggests that patients who underwent MRI were just as likely to achieve good functional recovery as those who underwent CT. The consistency of this finding was further supported by subgroup analyses, which showed similar results among patients who received endovascular treatment and those who were managed with best medical care alone.

A critical concern in acute stroke management is the potential delay in treatment initiation caused by more complex imaging procedures. MRI scans typically require more time to perform and process compared to CT scans, which has historically raised concerns that choosing MRI might delay the critical step of arterial puncture for thrombectomy. However, the study found no significant workflow delays associated with MRI. The mean difference in time from stroke onset to randomization was only 5.23 minutes, with a p-value of 0.843, indicating no statistically significant difference. Similarly, the time from onset to arterial puncture showed a mean difference of 13.16 minutes, with a p-value of 0.701, further confirming that MRI did not hinder the speed of treatment initiation.

The technical implications of these findings are significant for stroke centers aiming to optimize their diagnostic pathways. Computed tomography has long been the standard of care for initial stroke evaluation due to its speed and ability to quickly rule out hemorrhagic stroke. However, MRI, particularly diffusion-weighted imaging, provides more detailed information about the extent of irreversible brain injury, which can be crucial for selecting patients for endovascular therapy. The study’s findings suggest that in the specific context of basilar artery occlusion, the additional diagnostic detail provided by MRI does not translate into a measurable benefit in patient selection or outcome prediction compared to conventional CT.

This conclusion aligns with broader trends in stroke research, where the focus has shifted from identifying the perfect imaging tool to ensuring that the chosen tool integrates seamlessly into the clinical workflow. Previous studies, such as the SWIFT-DIRECT subanalysis, have also explored the comparison between MRI and CT for large artery ischemic stroke, often highlighting the trade-offs between diagnostic accuracy and speed. The current study adds to this body of evidence by specifically addressing the posterior circulation, where the anatomy and clinical presentation of stroke differ significantly from the anterior circulation.

The authors emphasize that conventional imaging appears sufficient as a first-line tool for selecting patients in clinical practice. This recommendation is particularly relevant for hospitals that may not have immediate access to MRI scanners or for those where MRI availability is limited during peak emergency hours. By validating the efficacy of CT, the study supports a streamlined approach to stroke care that prioritizes speed and accessibility without compromising patient outcomes. This is especially important given the high mortality and morbidity rates associated with basilar artery occlusion, where rapid intervention is critical for survival.

Furthermore, the study’s findings have implications for the development of future stroke trials and clinical guidelines. As the field moves toward more personalized medicine, the ability to quickly and accurately assess patients using widely available tools becomes increasingly important. The consistency of the results across different time windows suggests that the choice of imaging modality is robust and not dependent on the specific timing of patient presentation. This robustness enhances the generalizability of the findings and their applicability to diverse clinical settings.

In conclusion, this post hoc analysis of the ATTENTION trial demonstrates that there is no evidence to support the preferential use of MRI over CT as the primary imaging strategy for patient selection in acute basilar artery occlusion. Both modalities provide comparable outcomes in terms of functional recovery and workflow efficiency. These findings reinforce the role of computed tomography as a reliable and efficient first-line imaging tool in the acute management of basilar artery occlusion, allowing clinicians to focus on rapid treatment initiation rather than the complexities of advanced imaging. As stroke care continues to evolve, such studies are essential for refining clinical protocols and ensuring that patients receive the most effective and timely care possible.

Subject of Research: Magnetic resonance imaging vs computed tomography for baseline imaging evaluation in acute basilar artery occlusion

Article Title: Magnetic resonance imaging vs computed tomography for baseline imaging evaluation in acute basilar artery occlusion

Article References: Gao, F., Nguyen, T. N., Wang, A., Li, R., Xu, P., Chen, Y., Nogueira, R. G., Fang, S., & Hu, W. (2026). Magnetic resonance imaging vs computed tomography for baseline imaging evaluation in acute basilar artery occlusion. Journal of Neurology, 273(11), Article 670. https://doi.org/10.1007/s00415-026-14159-4

Image Credits: AI Generated

DOI: 10.1007/s00415-026-14159-4

Keywords: Magnetic, resonance, imaging, computed, tomography, baseline, evaluation, acute, basilar, artery, occlusion, scientific research