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Simultaneous PET/MRI Imaging During Mouse Cerebral Hypoxia-ischemia
Published on: September 20, 2015
ApoE polymorphism and acute stroke: a study with diffusion- and perfusion-weighted MRI and MR angiography
Y Liu1, J Nuutinen, M P Laakso
1Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland.
Objectives:
We examined whether the apolipoprotein E (ApoE) allele epsilon4 influences imaging findings in stroke as assessed by diffusion- (DWI) and perfusion-weighted (PWI) magnetic resonance imaging, and MR angiography (MRA).
Methods:
Eight ApoE epsilon4 carriers and 15 non-carriers with acute ischemic stroke in the anterior circulation underwent DWI, PWI, and MRA within 24 h of stroke. DWI and PWI were repeated a week later. The apparent diffusion coefficient, relative cerebral volume (rCBV), relative cerebral blood flow (rCBF) and relative mean transit time were measured in three subregions on day one.
Results:
In the ischemic core and the area of infarct growth, rCBV values were significantly higher in the epsilon4 carriers compared with the non-carriers. Based on the MRA findings, collateral blood flow was better in the epsilon4 carriers than in the non-carriers. Under the comparable severity of hypoperfusion, the hypoperfused area proceeded to infarction later or did not proceed to infarction at all in the non-carriers.
Conclusion:
These preliminary data suggest that in the ApoE allele epsilon4 carriers the threshold for the brain tissue to survive hypoperfusion versus to proceed to infarction seems to be different from that of the non-carriers.
Insights
The apolipoprotein E (ApoE) epsilon4 allele may alter how brain tissue responds to stroke. ApoE epsilon4 carriers showed better collateral blood flow and different infarction thresholds compared to non-carriers.
Area of Science:
- Neuroimaging
- Cerebrovascular disease
- Genetics
Background:
- The apolipoprotein E (ApoE) epsilon4 allele is a known risk factor for various neurological conditions, including stroke.
- Understanding how genetic factors influence stroke pathophysiology is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the impact of the ApoE epsilon4 allele on imaging characteristics in acute ischemic stroke.
- To assess differences in diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI), and MR angiography (MRA) findings between ApoE epsilon4 carriers and non-carriers.
Main Methods:
- Eight ApoE epsilon4 carriers and 15 non-carriers with anterior circulation ischemic stroke underwent serial DWI, PWI, and MRA within 24 hours of stroke onset.
- Quantitative imaging parameters including apparent diffusion coefficient, relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and relative mean transit time were measured.
- Collateral blood flow was assessed using MRA.
Main Results:
- ApoE epsilon4 carriers exhibited significantly higher rCBV values in the ischemic core and infarct growth areas compared to non-carriers.
- MRA revealed better collateral blood flow in ApoE epsilon4 carriers.
- In cases of comparable hypoperfusion severity, non-carriers showed delayed or absent progression to infarction in the hypoperfused area.
Conclusions:
- Preliminary findings suggest that ApoE epsilon4 allele carriers may have a different threshold for brain tissue survival during hypoperfusion compared to non-carriers.
- The ApoE epsilon4 allele appears to influence the brain's response to ischemic events, potentially affecting infarct development and progression.