A thin-cap fibroatheroma with a large necrotic core and macrophage infiltration marks the vulnerable plaque. Fibroblast activating protein (FAP) is an active serine protease, which can degrade type I collagen, potentially thinning the fibrous cap. Thus we speculate that atherosclerotic plaque could be imaged with 68Ga-FAPI PET/MR.

A thin-cap fibroatheroma with a large necrotic core and macrophage infiltration marks the vulnerable plaque. Fibroblast activating protein (FAP) is an active serine protease, which can degrade type I collagen, potentially thinning the fibrous cap. Previous ex vivo analysis of human aortic atheromata revealed that FAP was expressed in atherosclerotic plaques, and higher FAP expression was detected in thin fibrous caps than thick caps. Constitutive Fap deletion in atherosclerosis-prone mice models could reduce plaque formation and improve plaque stability with increased fibrous cap thickness. Thus we speculate that atherosclerotic plaque could be imaged with 68Ga-FAPI PET/MR.

Inclusion Criteria:

• intracranial or carotid atherosclerosis patients
• signed informed consent

Exclusion Criteria:

• pregnancy, breastfeeding
• contradictions of MRI
• unstable vital signs