To explore the stroke mechanism evolution in patients with intracranial atherosclerotic stenosis by magnetic resonance imaging(MRI) from current first stroke to follow up stroke recurrence. Diffusion weighted imaging was to identify basic stroke mechanism. High resolution MRI and perfusion imaging was to monitor the dynamic changes of vulnerable atherosclerotic plaque and hemodynamic status including antegrade flow and collateral circulation.
Patients with symptomatic and asymptomatic intracranial atherosclerotic stenosis were included. Baseline materials including risk factors, NIH stroke scale score, modified Rankin Scale at admission, time from sympton onset to imaging were recorded. Current stroke mechanism was identified by diffusion weighted imaging as In situ thrombotic occlusion, artery-to-artery embolism, hemodynamic impairment, branch occlusive disease and mixed mechanism. High resolution MRI(HRMRI) was to detect atherosclerotic plaque and depict plaque characteristics and vulnerability. Perfusion imaging was to monitor the dynamic changes hemodynamic status including antegrade flow and collateral circulation.
T2 weighted imaging, T1 weighted imaging, Diffusion weighted image(DWI), fluid-attenuated inversion recovery(FLAIR), three dimensional high resolution black blood T1 weighted imaging, Perfusion weighted image(PWI), arterial spin labeling(ASL) with Post labeling delay(PLD) 1.5s and 2.5s, Territory ASL(TASL) (PLD = 2.0s), 3D inversion recovery (IR)-prepared fast spoiled gradient recalled echo (FSPGR).
Contrast agent: Omniscan 2ml/kg, Inject rate：3ml/s
1. Antegrade flow and collateral assessment by ASL Cerebral blood flow(CBF) maps and TASL CBF maps.
2. Hemodynamic status assessment by PWI multi-parameter postprocessing map.
3. FLAIR hyperintensity vascular sign.
Intravenous recombinant tissue plasminogen activator(rtPA), endovascular therapy and conventional treatment including neuro protection, ante-platelet and statin.
A month imaging follow up and clinical stroke event and modified Rankin Scale(mRS) record in 2 years.
Imaging sequences analysis and optimization:
Three dimensional high resolution black blood T1 weighted imaging and ASL imaging quality evaluation and parameters optimization.
- Observation: Cohort
- Perspective: Prospective
- Sampling: Non-Probability Sample
Symtomatic or asymtomatic patients with intracranial atherosclerostic stenosis
|Type||Measure||Time Frame||Safety Issue|
|Primary||Ischemic stroke event||Three months to 2 year||Yes|
|Secondary||modified Rankin Score||Three months to 1 year||Yes|
|Secondary||Magnetic Resonance Imaging sequences analysis and optimization||Three months to 1 year||Yes|