[Imaging of vulnerable plaque]

Atherosclerosis is a dynamic degenerative disease, which can suddenly switch from a chronic condition to clinical instability, following a process of plaque rupture and thrombotic formation. Lesions at instability risk are described as "vulnerable plaque", i.e., lesions with a future high probability of becoming an acute event. Present diagnostic and screening methods are inadequate to identify these lesions. Recent ongoing research addresses two modalities: the development of non-invasive imaging techniques for a rapid diagnostic screening of middle-low risk coronary disease, and the implementation of invasive imaging microscopic techniques--involving the coronary wall--which are associated with coronarography. Some techniques (intravascular ultrasound-optical coherence tomography)--recently introduced in the clinical setting--allow in vivo monitoring of the sequence of changes in the plaque. For the first time we have now the possibility of measuring the thickness of the fibrous cap, the presence of neo-vessels and probably the density of macrophages, identifying high-risk plaques. The imaging techniques allow to track the evolution of the atherosclerotic disease (plaque volume, thickness of cap, number of thin cap plaques) assessing its progression and regression and the efficacy of treatments.