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Updated: Aug 13, 2026
Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat
Published on: February 5, 2011
T2-weighted MRI correlates with long-term histopathology, neurology scores, and skilled motor behavior in a rat
G C Palmer1, J Peeling, D Corbett
1AstraZeneca R&D Boston, 3 Biotech, One Innovation Dr. Worcester, Massachusetts, USA. eugene.palmer@astrazeneca.com
Abstract:
The intraluminal suture model of transient middle cerebral artery occlusion (MCAO) in the Sprague Dawley strain of rats characteristically results in an inconsistently sized brain lesion. The purpose of the investigation reported here was to determine whether there were strong point-to-point correlations between the degree of cortical lesion size, as assessed in vivo using T2-weighted magnetic resonance imaging (MRI) and corresponding cortical lesion size using routine histopathological techniques. Moreover, we aimed to investigate if cortical lesion size as determined by these two modalities correlates with neurological and/or skilled motor deficits observed in individual animals. Baseline behavioral scores were obtained on the animals prior to receiving 60 min of transient MCAO. Following MCAO, animals were tested for 1-21 days for neurological deficits. T2-weighted MRIs of the cortex were taken at two and seven days post-MCAO. At 30 and 60 days the rats were retested for forelimb dexterity in the staircase test. Subsequently, the cortex was examined for histopathological damage. Indeed, there were highly significant correlations between lesion size determined by MRI and histopathology. The degree of cortical damage observed in the T2-weighted MRI, as well as the size of the histopathological lesions were, in turn, highly correlated with the degrees of deficiencies observed in the composite neurological assessments and with the deficits involving skilled use of the contralateral forepaw (damaged side).
Insights
This study found that T2-weighted MRI accurately measures stroke lesion size in rats after middle cerebral artery occlusion (MCAO). Lesion size correlated with neurological and motor deficits, validating MRI as a reliable assessment tool.
Area of Science:
- Neuroscience
- Medical Imaging
- Stroke Research
Background:
- The intraluminal suture model of transient middle cerebral artery occlusion (MCAO) in rats often produces variable brain lesion sizes.
- Accurate assessment of lesion volume is crucial for understanding stroke pathophysiology and evaluating therapeutic interventions.
Purpose of the Study:
- To correlate in vivo T2-weighted MRI measurements of cortical lesion size with histopathological findings.
- To determine if MRI- and histopathology-derived lesion sizes correlate with neurological and skilled motor deficits in individual rats.
Main Methods:
- Transient middle cerebral artery occlusion (MCAO) was induced in Sprague Dawley rats.
- Neurological and skilled forelimb motor function (staircase test) were assessed before and after MCAO (1-21 days).
- T2-weighted MRI was performed at 2 and 7 days post-MCAO; histopathology was conducted at 30 and 60 days.
Main Results:
- A highly significant correlation was observed between cortical lesion size measured by T2-weighted MRI and histopathology.
- Both MRI- and histopathology-determined lesion sizes strongly correlated with the severity of neurological deficits.
- Cortical damage size also correlated significantly with deficits in skilled contralateral forepaw use.
Conclusions:
- T2-weighted MRI provides a reliable in vivo assessment of cortical lesion size following transient MCAO in rats.
- MRI-based lesion volume is a strong predictor of functional neurological and motor impairments after stroke.
- This validates the use of MRI for quantifying stroke pathology and its functional consequences in preclinical models.
