Intravascular Optical Coherence Tomography Detection of Atherosclerosis and Inflammation in Murine Aorta
Objective—The goal of this study was to evaluate the feasibility of imaging the aorta of apolipoprotein E–deficient (ApoE−/−) mice for the detection of atherosclerosis and macrophages using optical coherence tomography (OCT) compared with histology.
Methods and Results—Atherosclerosis was induced by high-fat diet in 7-week-old ApoE−/− mice for 10 (n=7) and 22 (n=7) weeks. Nine-week-old ApoE−/− mice (n=7) fed a standard chow diet were used as controls. OCT images of a 10-mm descending aorta in situ were performed in 4 mice for each, and plaque and macrophages were determined at 0.5-mm intervals. Automated detection and quantification of macrophages were performed independently using a customized algorithm. Coregistered histological cross-sections were stained with hematoxylin-eosin, Mac-3, and von Kossa. Three mice in each group had en face OCT imaging to detect macrophages, which were compared with lipid-positive area with Sudan IV. OCT images were successfully acquired in all mice. OCT and histology were able to discriminate macrophages and plaque among the 3 groups and showed excellent correlation for (1) visual detection of plaque (r=0.98) and macrophages (r=0.93), (2) automated detection and quantification of macrophages by OCT versus Mac-3-positive area (r=0.92), and (3) en face OCT detection of macrophages versus Sudan IV–positive area (r=0.92).
Conclusion—Murine intraaortic OCT is feasible and shows excellent correlation with histology for detection of atherosclerotic plaque and macrophages.
- Received July 2, 2011.
- Accepted December 28, 2011.
- © 2012 American Heart Association, Inc.