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Updated: Jun 20, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Total mismatch: negative diffusion-weighted imaging but extensive perfusion defect in acute stroke
Background And Purpose:
The perfusion-weighted imaging (PWI)/diffusion-weighted imaging (DWI) mismatch may identify patients who benefit from thrombolysis. However, some patients exhibit a "total mismatch," ie, negative DWI but extensive PWI defect. We aimed to assess clinical and MRI data of these patients.
Methods:
From June 2007 to December 2008, patients with anterior circulation ischemic stroke were evaluated for a "total mismatch" profile. MRI was performed at admission and at day 1. The score was assessed at baseline and the modified Rankin scale score was assessed at day 30.
Results:
Among 52 patients, 3 showed a total mismatch with arterial occlusion confirmed on magnetic resonance angiography. All had fluctuating symptoms (National Institutes of Health Stroke Scale scores, 0 to 10) and received intravenous tissue plasminogen activator. Day 1 DWI disclosed minimal changes in all patients. Outcome was favorable in all patients (day 30 modified Rankin scale, 0-1).
Conclusion:
PWI may be helpful for treatment decisions in patients without DWI damage and fluctuating clinical course.
Insights
Perfusion-weighted imaging (PWI) may identify stroke patients benefiting from thrombolysis, even with negative diffusion-weighted imaging (DWI). This "total mismatch" profile indicates favorable outcomes with prompt treatment.
Area of Science:
- Neuroimaging
- Stroke Medicine
- Radiology
Background:
- Perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) are crucial for identifying acute ischemic stroke patients eligible for thrombolysis.
- A 'total mismatch' profile, characterized by normal DWI and extensive PWI deficits, presents a diagnostic challenge.
- This study investigates the clinical and MRI characteristics of patients with a total mismatch profile.
Discussion:
- Patients with a total mismatch profile and arterial occlusion showed fluctuating symptoms.
- Prompt administration of intravenous tissue plasminogen activator (tPA) was associated with minimal Day 1 DWI changes.
- The findings suggest that PWI can guide treatment decisions in select stroke cases.
Key Insights:
- A total mismatch (normal DWI, large PWI defect) in anterior circulation ischemic stroke is rare but associated with favorable outcomes.
- All identified patients with total mismatch received thrombolysis and showed good recovery.
- Fluctuating clinical symptoms in these patients warrant careful consideration of advanced imaging.
Outlook:
- Further research is needed to validate the utility of PWI in guiding thrombolysis decisions for patients with total mismatch.
- Exploring the long-term outcomes and specific treatment protocols for this patient subgroup is essential.
- Integrating advanced neuroimaging techniques can refine stroke treatment strategies.
