Targeted Enzyme-Specific Molecular MR Imaging of Focal Catheter-Induced Vacscular Injury

Catheter-induced vascular injury is a complication of endovascular neurosurgery that may have serious consequences. Other than gross vessel dissection and / or perforation, vessel damage is not visible using standard digital biplane fluoroscopy. Furthermore, the molecular environment in the damaged vessel wall is largely unknown. Recent studies have implicated inflammatory changes in the damaged vessel wall, including upregulation of the key inflammatory mediator NF-kappa-B [1]. Other mediators of inflammation, such as tissue inhibitors of matrix metalloproteinases, are upregulated following arterial de-endothelialization [2]. The enzyme myeloperoxidase (MPO) is known to play significant roles in the progression of vascular pathologies such as atherosclerosis. However, it is unknown whether MPO is involved in catheter-induced vascular injury. In this study, we performed feasibility experiments in an attempt to detect areas of vascular injury using the paramagnetic MR MPO-specific contrast agent, di-5-HT-GdDTPA, which has been shown to be sensitive and specific for MPO both in vitro and in vivo.