Among young adults with ischaemic stroke who ultimately met the imaging criteria for IAD, initial MRI/MRA alone was insufficient to establish the diagnosis in most cases, and repeated and multimodal imaging contributed to the diagnosis of IAD.
Initial MRI/MRA identified intracranial artery dissection in only a minority of young adult stroke patients who were ultimately diagnosed with IAD.
Vessel wall MRI had the highest observed diagnostic yield among all imaging modalities used to identify IAD.
Follow-up MRI/MRA performed 7 days after admission had a substantially higher diagnostic yield than initial MRI/MRA.
Digital subtraction angiography and CT angiography had intermediate and low diagnostic yields, respectively, for IAD detection.
The median time to IAD diagnosis was 5 days after admission, with some cases not diagnosed until over a month after admission.
The study was a secondary analysis of a prospective, multicentre registry of young adults with acute ischaemic stroke.
This research suggests that a single MRI/MRA scan taken when a young adult arrives at the hospital with a stroke frequently misses a type of blood vessel injury called intracranial artery dissection (IAD), where the inner lining of an artery in the brain tears. In this study of 275 stroke patients between ages 18 and 50, only about 1 in 6 patients who were eventually found to have IAD were correctly identified on the first scan. This means that if doctors rely solely on the initial imaging, most cases of IAD would go undetected at first. The research found that repeating the MRI/MRA scan about a week later, and using additional specialized imaging techniques—particularly a method called vessel wall MRI (VW-MRI)—dramatically improved the chances of detecting IAD. VW-MRI correctly identified IAD in 84% of patients who received it, while the follow-up standard MRI/MRA identified 77% of cases. On average, the correct diagnosis was made about 5 days after hospital admission, though some cases were not identified until more than a month later. This highlights that IAD can be a diagnosis that emerges over time rather than being apparent immediately. Practically, this study suggests that for young adults who have a stroke without an obvious cause, a single initial brain scan may not be enough to rule out IAD. Follow-up imaging and more specialized scans appear to be important tools for reaching the correct diagnosis. Identifying IAD matters because it can influence decisions about treatment and monitoring to prevent further strokes.
Makita N, Ohara T, Makino M, Tanaka E, Fukunaga D, Tokuda N, et al.. (2026). Initial magnetic resonance imaging/magnetic resonance angiography may miss intracranial artery dissection in young adults with stroke: the role of subsequent imaging.. European stroke journal. https://doi.org/10.1093/esj/aakag115