Author/Authors :
Vavuranakis, Manolis First Department of Cardiology - Hippokration Hospital - Biomedical Engineering Unit - Medical School - National and Kapodistrian University - Athens - Greece , Papaioannou, Theodore G. First Department of Cardiology - Hippokration Hospital - Biomedical Engineering Unit - Medical School - National and Kapodistrian University - Athens - Greece , Vrachatis, Dimitrios First Department of Cardiology - Hippokration Hospital - Biomedical Engineering Unit - Medical School - National and Kapodistrian University - Athens - Greece , Katsimboulas, Michael Centre of Clinical - Experimental Surgery and Translational Research - Experimental Surgery Unit - Biomedical Research Foundation of the Academy of Athens – Athens - Greece , Sanidas, Elias A. Department of Cardiology - “Laiko” General Hospital - Athens - Greece , Vaina, Sophia First Department of Cardiology - Hippokration Hospital - Biomedical Engineering Unit - Medical School - National and Kapodistrian University - Athens - Greece , Agrogiannis, George Department of Pathology - Medical School - National and Kapodistrian University – Athens - Greece , Patsouris, Efstratios Department of Pathology - Medical School - National and Kapodistrian University – Athens - Greece , Kakadiaris, Ioannis Computational Biomedicine Lab - Department of Computer Science - University of Houston – TX - USA , Stefanadis, Christodoulos First Department of Cardiology - Hippokration Hospital - Biomedical Engineering Unit - Medical School - National and Kapodistrian University - Athens - Greece , Tousoulis, Dimitrios First Department of Cardiology - Hippokration Hospital - Biomedical Engineering Unit - Medical School - National and Kapodistrian University - Athens - Greece
Abstract :
Objective: Neoangiogenesis is pathophysiologically related to atherosclerotic plaque growth and vulnerability. We examined the in vivo performance of a computational method using contrast-enhanced intravascular ultrasound (CE-IVUS) to detect and quantify aortic wall neovascularization in rabbits. We also compared these findings with histological data.
Methods: Nine rabbits were fed with a hyperlipidemic diet. IVUS image sequences were continuously recorded before and after the injection of a contrast agent. Mean enhancement of intensity of a region of interest (MEIR) was calculated using differential imaging algorithm. The percent difference of MEIR before and after the injection of microbubbles (d_MEIR) was used as an index of the density of plaque or/and adventitial neovascularization. Aortic segments were excised for histological analysis.
Results: CE-IVUS and histological analysis were performed in 11 arterial segments. MEIR was significantly increased (~20%) after microbubble injection (from 8.1±0.9 to 9.7±1.8, p=0.016). Segments with increased VV/neovessels in the tunica adventitia (histological scores 2 and 3) had significantly higher d_MEIR compared with segments with low presence of VV/neovessels (score 1); 40.5±22.9 vs. 8±14.6, p=0.024, respectively.
Conclusion: It is possible to detect VV or neovessels in vivo using computational analysis of CE-IVUS images, which is in agreement with histological data. These findings may have critical implications on vulnerable plaque assessment and risk stratification.
Keywords:
Keywords :
neoangiogenesis , microbubbles , vulnerable plaque , aorta , atherosclerosis
