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Published on: September 25, 2016
Susceptibility-weighted imaging for cerebral microbleed detection in super-acute ischemic stroke patients treated
Qingke Bai1, Zhenguo Zhao, Haijing Sui
1Department of Neurology, Pudong People's Hospital, Shanghai, China.
Objective:
Fast magnetic resonance imaging (MRI) and susceptibility-weighted imaging (SWI) methods may provide more accurate detection of the highly variant time window for successful intravenous (IV) thrombolytic drug treatment (averaging 3 hours) for cerebral microbleeds (CMBs) in acute stroke patients.
Methods:
This prospective study applies fast MRI and SWI for examination of 279 prescreened ischemic stroke patients within 12 hours of stroke onset. One hundred and sixty-two (58.1%) of 279 patients were diagnosed with super-acute ischemic stroke with restricted diffusion, hyperintense diffusion-weighted imaging signals, and no ischemic change in T2-weighted imaging, fluid-attenuated inversion recovery, or T1-weighted imaging signals. Recombinant tissue plasminogen activator IV thrombolysis was administered to 113 (69.75%) patients (thrombolysis group). All patients underwent regular sequence MRI and SWI follow-up.
Results:
Computed tomography and MRI sequence scans revealed hemorrhagic transformations in 13 (11.50%) thrombolysis and four (8.16%) non-thrombolysis group patients. MRI-guided thrombolysis treatment produced no significant differences between the two groups. SWI revealed new CMBs in 46 (40.70%) and nine (18.37%) thrombolysis and non-thrombolysis group patients, respectively. Significantly better National Institutes of Health stroke scale (24 hours) (P<0.05), modified Rankin scale (90 days) (P<0.01), and life quality Barthal index scores were observed in CMB patients (P<0.01).
Conclusions:
SWI revealed higher CMB incidence and clinical improvement in recombinant tissue plasminogen activator IV thrombolysis-treated super-acute ischemic stroke patients, suggesting that CMBs may indicate vascular re-canalization/reperfusion. Thus, SWI can be applied to extend individual patient windows for thrombolytic treatment beyond general recommendations of treatment within 3 hours, allowing treatment up to 12 hours from stroke onset.
Insights
Susceptibility-weighted imaging (SWI) detects more cerebral microbleeds (CMBs) in acute stroke patients receiving thrombolysis, indicating improved outcomes. This suggests SWI can extend treatment windows up to 12 hours for stroke patients.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Acute ischemic stroke treatment relies on timely reperfusion therapy.
- Intravenous thrombolysis is time-sensitive, typically within 3 hours of symptom onset.
- Cerebral microbleeds (CMBs) are common in stroke patients and can influence treatment decisions.
Purpose of the Study:
- To evaluate the utility of fast magnetic resonance imaging (MRI) and susceptibility-weighted imaging (SWI) for detecting cerebral microbleeds (CMBs).
- To assess the impact of CMBs on clinical outcomes in acute ischemic stroke patients treated with recombinant tissue plasminogen activator (rt-PA).
- To determine if SWI can help extend the treatment window for IV thrombolysis.
Main Methods:
- Prospective study of 279 ischemic stroke patients within 12 hours of onset.
- Utilized fast MRI and SWI for imaging.
- Compared outcomes between patients receiving rt-PA thrombolysis and those who did not.
Main Results:
- SWI identified a higher incidence of CMBs in the thrombolysis group (40.70%) compared to the non-thrombolysis group (18.37%).
- Patients with CMBs showed significantly better functional outcomes at 24 hours (NIH Stroke Scale) and 90 days (modified Rankin Scale, Barthel Index).
- Hemorrhagic transformations occurred in 11.50% of the thrombolysis group and 8.16% of the non-thrombolysis group, with no significant difference.
Conclusions:
- SWI is effective in detecting CMBs in acute ischemic stroke patients.
- The presence of CMBs in rt-PA treated patients suggests potential for vascular recanalization and correlates with improved clinical outcomes.
- SWI may enable extended thrombolytic treatment windows for selected stroke patients up to 12 hours post-onset.
