Multislice diffusion mapping for 3-D evolution of cerebral ischemia in a rat stroke model

Area of Science:

• Neuroimaging
• Cerebrovascular Research
• Medical Physics

Background:

• Cerebral ischemia requires rapid detection for effective treatment.
• Diffusion-weighted magnetic resonance imaging (DWI) offers quantitative insights into ischemic changes.
• Understanding the spatiotemporal evolution of ischemia is crucial for stroke modeling.

Purpose of the Study:

• To evaluate the capability of 3-D multislice DWI and apparent diffusion coefficient (ADC) mapping for early detection and monitoring of ischemic evolution.
• To characterize the 3-D spread and development of cerebral ischemia in a rat stroke model.

Main Methods:

• Utilized diffusion-weighted echo-planar multislice magnetic resonance imaging (DWI).
• Mapped apparent diffusion coefficient (ADC) values to identify and quantify ischemic regions.
• Monitored 13 time points from 5 to 180 minutes post-middle cerebral artery (MCA) occlusion in a rat model.

Main Results:

• Reduced ADC values, indicative of ischemia, were detected as early as 5 minutes after MCA occlusion.
• The ischemic core initially appeared in the lateral caudoputamen and frontoparietal cortex, subsequently spreading.
• A strong correlation was observed between the 180-minute DWI-derived ischemic volume and postmortem infarct volume (r = 0.72, p < 0.05).

Conclusions:

• 3-D multislice diffusion mapping noninvasively detects cerebral ischemia within 5 minutes of MCA occlusion.
• This technique allows for monitoring the 3-D evolution and spread of focal ischemia over time.
• ADC value changes provide critical information regarding the dynamic development of ischemic brain injury.