Intracranial Vessel Wall MRI in a Rabbit Elastase Aneurysm Model

Background: Intracranial aneurysms have a high mortality rate and can cause devastating neurological damage, despite modern therapies. Inflammation has been shown to play a key role in remodeling of intracranial aneurysms and progression to rupture. Intracranial vessel wall MRI has emerged as a promising way of evaluating inflammatory changes in intracranial blood vessels. We propose that intracranial vessel wall MRI is a feasible technique in a rabbit elastase aneurysm model and may be a biomarker of aneurysm inflammation in this model.

Methods: Following an established rabbit aneurysm model, aneurysms were induced in 24 adult New Zealand rabbits using reconstituted elastase. 12 rabbits were treated with daily oral aspirin for three weeks. Intracranial vessel wall MRI was obtained for each rabbit prior to initiation of treatment with aspirin and then after treatment. The remaining 12 rabbits received no treatment and intracranial vessel wall MRI was performed after induction of aneurysms and then three weeks later. Aneurysm sections were subsequently dissected and assessed histologically.

Results: Intracranial vessel wall MRI was able to be obtained in each rabbit, prior to and after treatment. Aneurysm formation was able to be identified and vessel wall enhancement was observed. Vessel wall enhancement corresponded to inflammatory changes on histological sections.

Conclusion: Intracranial vessel wall MRI is a feasible technique in a rabbit elastase aneurysm model. Vessel wall enhancement corresponded to inflammatory changes on histological sections. Our findings suggest that this may potentially be used as an imaging biomarker of aneurysm inflammation in this model.

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No conflict of interest has been declared by the author(s).