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Updated: Jul 5, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Safety and efficacy of MRI-based thrombolysis in unclear-onset stroke. A preliminary report
A-Hyun Cho1, Sung-Il Sohn, Moon-Ku Han
1Department of Neurology, University of Ulsan College of Medicine, Seoul, Korea.
Background:
Standard selection criteria for thrombolysis typically exclude patients with acute ischemic stroke with unclear onset. Multimodal MRI screening may be able to identify those with a favorable benefit-risk ratio for thrombolysis. We aimed to evaluate the safety and efficacy of MRI-based thrombolysis in unclear-onset stroke (UnCLOS).
Methods:
We reviewed the thrombolysis database registries from 3 medical centers in Korea. Subjects received thrombolysis with intravenous tissue plasminogen activator (tPA) or combined intravenous tPA and intra-arterial urokinase within 3 h, or intra-arterial urokinase within 6 h from symptom detection. For patients with UnCLOS, MRI-specific eligibility criteria (i.e. positive perfusion-diffusion mismatch and absence of well-developed fluid-attenuated inversion recovery changes of acute diffusion lesions) were applied. Rates of immediate and 5-day recanalization, early neurological improvement and symptomatic intracranial hemorrhage (ICH) within 48 h after treatment and 3-month modified Rankin Scale (mRS) scores were compared between patients with UnCLOS and those with clear-onset stroke (CLOS).
Results:
32 patients with UnCLOS and 223 patients with CLOS were included. Baseline characteristics were comparable between the two groups, except that the proportion of MRI screening was higher, and detection-to-door time and door-to-needle time were longer in the UnCLOS group (p < 0.01). Rates of recanalization (immediate, 81.3 vs. 63.1%; delayed, 80.6 vs. 69.1%), early neurological improvement (on day 1, 46.9 vs. 35.9%; on day 7, 50.0 vs. 49.3%), symptomatic ICH (6.3 vs. 5.8%) and 3-month outcome (mRS 0-1, 37.5 vs. 35.0%; mRS 0-2, 50.0 vs. 49.3%) did not differ between the UnCLOS and CLOS groups.
Conclusion:
These preliminary results suggest that thrombolysis based on MRI criteria may safely be applied to acute stroke patients with unclear onset.
Insights
Magnetic Resonance Imaging (MRI) criteria enable safe thrombolysis for acute ischemic stroke patients with unclear onset. This approach shows comparable safety and efficacy to clear-onset stroke treatment, expanding treatment eligibility.
Area of Science:
- Neurology
- Radiology
- Emergency Medicine
Background:
- Standard thrombolysis criteria exclude acute ischemic stroke patients with unclear onset times.
- Multimodal MRI may identify patients with a favorable benefit-risk ratio for thrombolysis.
- Unclear-onset stroke (UnCLOS) poses a challenge for timely treatment.
Purpose of the Study:
- To evaluate the safety and efficacy of MRI-based thrombolysis in patients with unclear-onset stroke (UnCLOS).
- To compare outcomes between UnCLOS patients treated with MRI guidance and clear-onset stroke (CLOS) patients.
Main Methods:
- Retrospective review of thrombolysis database registries from three Korean medical centers.
- Application of MRI-specific eligibility criteria (perfusion-diffusion mismatch, absence of significant FLAIR changes) for UnCLOS patients.
- Comparison of recanalization rates, early neurological improvement, symptomatic intracranial hemorrhage (ICH), and 3-month functional outcomes (modified Rankin Scale - mRS) between UnCLOS and CLOS groups.
Main Results:
- 32 UnCLOS patients and 223 CLOS patients were analyzed; baseline characteristics were comparable.
- MRI screening was higher in the UnCLOS group, with longer detection-to-door and door-to-needle times.
- No significant differences were observed in recanalization rates, early neurological improvement, symptomatic ICH rates (6.3% vs. 5.8%), or 3-month mRS scores between the groups.
Conclusions:
- Preliminary findings suggest that thrombolysis guided by MRI criteria is safe for acute stroke patients with unclear onset.
- MRI-based selection may expand treatment options for UnCLOS patients.
- Further research is warranted to confirm these findings in larger cohorts.
