Related Experiment Video
Updated: Aug 13, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Silent ischemia in minor stroke and TIA patients identified on MR imaging
S B Coutts1, M D Hill, J E Simon
1Seaman Family MR Centre, Foothills Hospital, Calgary, Alberta T2N 2T9, Canada. shelagh.coutts@calgaryhealthregion.ca
Background:
In a general population of patients with stroke, the rate of new MRI lesions at 1 week was much higher than expected. With patients with minor stroke and TIA having a higher risk of recurrent clinical events, the authors examined whether patients with minor stroke and TIA also had a high rate of asymptomatic lesions on repeat MRI scanning.
Methods:
Patients with minor stroke and TIA presenting within 12 hours of symptom onset with a NIH Stroke Scale score less than six, who had a baseline MRI and a 1-month follow-up, were enrolled in this study. The follow-up study was examined for new diffusion-weighted imaging lesions as compared to the baseline study. Clinical or MRI factors predicting recurrent lesions were examined.
Results:
A total of 143 patients were enrolled and 14 patients (9.8%; 95% CI 5.4, 15.9) had MR evidence of new lesions at 30 days. Six of these new lesions were clinically asymptomatic (42.9%; 95% CI 17.7, 71.1). A trend to increased likelihood of new lesions at 30 days was seen with progressing baseline scan lesion number (none [2.2%], solitary [12.9%], multiple [19.8%]: p = 0.046). Patients whose mechanism of stroke was large artery or cardioembolic were the most likely to have new lesions on follow-up MRI.
Conclusion:
Minor stroke and TIA are associated with a 10% risk of new lesions on MRI and half of these new lesions are asymptomatic. This risk is lower than seen in more severely affected patients with stroke. Patients with multiple lesions at baseline are at an increased risk for new ischemic lesions.
Insights
Minor stroke and TIA patients have a 10% risk of new MRI lesions, with half being asymptomatic. Multiple baseline lesions increase this risk, indicating a need for careful monitoring in these stroke patients.
Area of Science:
- Neurology
- Radiology
- Neuroimaging
Background:
- New MRI lesions are common in stroke patients.
- Patients with minor stroke and transient ischemic attack (TIA) face a higher risk of recurrent clinical events.
- The rate of asymptomatic lesions on repeat MRI in minor stroke and TIA patients was previously unknown.
Purpose of the Study:
- To investigate the incidence of new MRI lesions in patients with minor stroke and TIA.
- To determine the proportion of asymptomatic new lesions in this patient group.
- To identify predictors of new ischemic lesions in minor stroke and TIA.
Main Methods:
- 143 patients with minor stroke or TIA within 12 hours of symptom onset and NIH Stroke Scale score < 6 were enrolled.
- Baseline and 1-month follow-up MRIs were compared for new diffusion-weighted imaging lesions.
- Clinical and MRI factors were analyzed to predict recurrent lesions.
Main Results:
- 9.8% of patients developed new MRI lesions at 30 days.
- 42.9% of these new lesions were asymptomatic.
- Increased likelihood of new lesions was associated with multiple baseline lesions (p=0.046) and stroke mechanisms like large artery or cardioembolic.
Conclusions:
- Minor stroke and TIA carry a 10% risk of new MRI lesions, with half being asymptomatic.
- This risk is lower than in more severely affected stroke patients.
- Baseline multiple lesions predict an increased risk of new ischemic lesions.
Related Concept Videos
01:21Imaging Studies for Cardiovascular System IV: CMRI
01:15Ischemic Stroke l: Introduction
01:15Ischemic Stroke ll: Pathophysiology
01:26Transient Ischemic Attack l: Introduction