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Updated: Apr 19, 2026
Endovascular Perforation Model for Subarachnoid Hemorrhage Combined with Magnetic Resonance Imaging MRI
Published on: December 16, 2021
New grading system based on magnetic resonance imaging in a mouse model of subarachnoid hemorrhage
Yusuke Egashira1, Hajime Shishido1, Ya Hua1
1From the Department of Neurosurgery, University of Michigan, Ann Arbor, MI.
Background And Purpose:
A grading system for experimental subarachnoid hemorrhage (SAH) that does not require animal euthanasia is currently unavailable. We proposed a new grading system based on MRI and evaluated the feasibility of this method in a mouse model of SAH.
Methods:
SAH was induced by endovascular perforation in adult male C57BL/6 mice. Mice underwent MRI 24 hours after SAH and were categorized into the following 5 grades based on T2*-weighted imaging: Grade 0, no visible SAH or intraventricular hemorrhage (IVH); Grade 1, minimal/localized SAH without IVH; Grade 2, minimal/localized SAH with IVH; Grade 3, thick/diffuse SAH without IVH; and Grade 4, thick/diffuse SAH with IVH. Neurological deficits were then assessed and the mice euthanized for conventional SAH grading.
Results:
Among a total of 47 mice, 4% were scored as grade 0, 30% as grade 1, 11% as grade 2, 30% as grade 3, and 26% as grade 4. This MRI grading had excellent interobserver reliability (weighted κ value =0.94), and there were strong correlations between the MRI grading and the conventional grading (r=0.85; P<0.001) or between MRI grade and neurological scores (r=-0.46; P<0.01).
Conclusions:
The new MRI grading correlated well with conventional grading and enabled in vivo evaluation of SAH severity. This grading system may offer advantages in future studies of experimental SAH.
