Longitudinal in vivo monitoring of atheroprogression in hypercholesterolemic mice using photoacoustic imaging

Background and aim- The ability to recognize and monitor atherosclerotic lesion development using non-invasive imaging is crucial in preventive cardiology. The aim of the present study was to establish a protocol for longitudinal monitoring of plaque lipid, collagen and macrophage burden as well as of endothelial permeability. Methods and results- Photoacoustic signals derived from endogenous or exogenous dyes assessed in vivo, in plaques of albino Apoe-/- mice, correlated with lesion characteristics obtained after histomorphometric and immunofluorescence analyses thus supporting the validity of our protocol. Using models of atheroprogression and –regression we could apply our imaging protocol to the longitudinal observation of atherosclerotic lesion characteristics in mice. Conclusions- The present study shows an innovative approach to assess arterial inflammation in a non-invasive fashion, applicable to longitudinal analyses of changes of atherosclerotic lesion composition. Such approach could prove important in the preclinical testing of therapeutic interventions in mice carrying pre-established lesions.