A Magnetic Resonance Imaging Contrast Agent Targeted Towards Activated Platelets Allows Detection of Platelets on Symptomatic Human Carotid Plaques

Fabian Meixner¹, Constantin von Zur Mhlen², Dominik Paul¹, Irene Neudorfer², Annette Merkle¹, Mirko Meissner¹, Christoph Bode², Jrgen Hennig¹, Dominik von Elverfeldt¹

Platelets play an important role in the rupture of atherosclerotic plaques. So far with imaging techniques like MRI/CT and coronary angiography, only the degree of atherosclerotic narrowing, but not the stage, and thus the potential risk of arterial wall changes can be observed. It would be an important advance in the diagnosis, to identify late stages of atherosclerosis to initiate early treatment measures. In this study, the imaging of activated platelets in symptomatic human atherosclerotic carotid plaques with a 9.4 Tesla MRI is under investigation. The contrast agent is a single-chain antibody (LIBS) to the activated form of GPIIb/IIIa receptor which is coupled to a micro-particle of iron oxide (MPIO). The contrast agent (LIBS-MPIO) binds to activated platelets attached to the endothelium of the carotid interna plaques and results in signal loss on MRI.