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Updated: Feb 26, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Magnetic resonance imaging characteristics of ischemic brain infarction over time in a canine stroke model
Sooyoung Choi1, Daji Noh2, Youngwhan Kim3
1Ian Animal Diagnostic Center, Seoul 06014, Korea.
Abstract:
This study describes magnetic resonance imaging (MRI) results and changes in lateral ventricular size over time in a canine ischemic stroke model. T1- and T2-weighted (T1W, T2W) imaging and fluid-attenuated inversion recovery (FLAIR) sequence MRI were performed at 3 h and 3, 8, and 35 days after brain infarct induction. Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping were performed at 8 and 35 days. A total of 29 brain lesions were induced successfully in 12 of 14 beagle dogs. At 3 h, T2W and FLAIR detected hyperintense lesions in three randomly selected dogs. On T1W, all lesions appeared hypointense to isointense at 3 h, isointense (18/29) or hypointense (11/29) at 3 days, hypointense to isointense with peripheral hyperintensity (24/26) at 8 days, and hypointense (18/26) at 35 days. Infarcts on DWI/ADC were hypointense to isointense centrally, with the periphery hyperintense/hyperintense (17/26) at 8 days and hypointense/hyperintense (19/26) at 35 days. A marked increase in lateral ventricular size was observed in dogs with cerebral infarcts. In conclusion, T2W and FLAIR were useful for detecting early stage (3 h to 3 days) brain infarction. T1W and DWI were useful for detecting neuronal necrosis and providing supplemental information for phase evaluation.
Insights
Magnetic resonance imaging (MRI) effectively detects canine ischemic stroke lesions early. T2-weighted and FLAIR sequences identify acute infarcts, while T1-weighted and diffusion-weighted imaging reveal neuronal damage and progression.
Area of Science:
- Neuroimaging
- Veterinary Neurology
- Stroke Research
Background:
- Ischemic stroke models in canines are crucial for understanding human stroke pathophysiology.
- Magnetic resonance imaging (MRI) is a key tool for diagnosing and monitoring brain lesions.
- Evaluating changes in ventricular size provides insights into brain tissue response to injury.
Purpose of the Study:
- To characterize magnetic resonance imaging (MRI) findings in a canine ischemic stroke model.
- To assess the temporal evolution of brain lesions and lateral ventricular size.
- To evaluate the utility of different MRI sequences for detecting infarcts at various stages.
Main Methods:
- Induction of cerebral infarcts in beagle dogs.
- Serial MRI scans including T1-weighted (T1W), T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) mapping.
- Imaging performed at 3 hours, 3, 8, and 35 days post-infarct induction.
Main Results:
- T2W and FLAIR MRI detected hyperintense lesions as early as 3 hours post-infarction.
- T1W imaging showed evolving lesion characteristics from hypointense to isointense over time.
- DWI/ADC mapping revealed infarct core and periphery changes, with significant lateral ventricular enlargement observed in affected dogs.
Conclusions:
- T2W and FLAIR MRI are valuable for early detection of canine brain infarction (3 hours to 3 days).
- T1W and DWI/ADC provide critical information on neuronal necrosis and lesion progression.
- Canine ischemic stroke models demonstrate significant secondary changes like ventricular dilation.
