Optical coherence tomography for serial in vivo imaging of aortic plaque in the rabbit: a preliminary experience

Abstract

BackgroundIn this pilot feasibility study, we aimed to establish a reproducible means of performing serial optical coherence tomography (OCT) procedures in the abdominal aorta of the cholesterol-fed rabbit.MethodsEight cholesterol-fed New Zealand White rabbits were assigned to abdominal aortic balloon injury at baseline (n=6) or as controls (n=2). Three of the balloon injured rabbits received statins from weeks 6 to 12 post balloon injury. OCT of the abdominal aorta in each rabbit was performed at baseline±week 6±week 12 via alternate vascular access points (left or right femoral artery or left carotid artery). OCT sequences were analysed to derive an indexed plaque volume and other OCT measures of plaque complexity, and results were compared between groups. Histopathological correlations with OCT images were made following terminal procedures.ResultsOf the 16 OCT procedures in these rabbits (6 at baseline, 4 at 6 weeks, 6 at 12 weeks), excellent and analysable images were obtained on 15 occasions (94%). Inability to obtain adequate arterial access for the OCT catheter was the major experimental limitation encountered in the early part of our experience. Balloon injured rabbits developed larger volume and more complex plaque than non-balloon injured rabbits on all OCT indices measured (eg, both mean plaque volume and lumen stenosis were approximately double in the balloon injured group, p<0.0001). A significant correlation between 12 week measures of plaque area by OCT and histology was demonstrated (Pearson correlation coefficient: 0.992, p<0.0001).ConclusionsOur preliminary experience suggests that serial OCT of the abdominal aorta in the New Zealand White rabbit is feasible and a potentially promising means of performing serial studies of aortic atherosclerosis.

Translocator Protein 18 kDa Tracer 18F-FDPA PET/CTA Imaging for the Evaluation of Inflammation in Vulnerable Plaques

“…18 F-FDPA was automatically synthesized by the CFN-MPS200 module (Sumitomo, Japan) as described previously. 13 Briefly, the 18 In Vivo PET/Computed Tomography Angiography (CTA) Imaging. All of the rabbits underwent 18 F-FDPA PET/ CTA imaging at 12, 16, and 24 weeks.…”

“…10 In addition, further 18F-FDPA) is a TSPO-targeted radiotracer for PET imaging. As an analogue of 18 F-DPA-714, it shows excellent binding affinity to TSPO and improved metabolic stability in vivo. 11,12 While being extensively employed for visualizing neurological disorders characterized by glial cell activation and neuroinflammation, its potential for detecting inflammation within atherosclerotic plaques remains unexplored.…”

“…14,15 The PSCK9-targeted antibody, evolocumab, has shown clinical success in reducing plaque vulnerability. 16 In this study, we aimed to investigate the feasibility of utilizing 18 F-FDPA PET imaging for assessing the inflammation in VAPs through macrophage infiltration detection with or without the intervention of evolocumab. The uptake of 18 F-FDPA in the atherosclerotic plaques was quantitatively measured by in vivo and ex vivo PET imaging and was then compared with the lipid accumulation, macrophage infiltration degree, and fibrous cap thickness measured by OCT imaging, TSPO expression assessed using Western blot and immunofluorescence staining, and other histopathological findings.…”

Three‐Dimensional Subharmonic Aided Pressure Estimation for Assessing Arterial Plaques in a Rabbit Model

“…Thus, New Zealand white (NZW) rabbits were chosen for the rest of the study, and 18 of them were studied. The NZW rabbit is also a popular model for human atherosclerosis studies . It develops hypercholesterolemia within a few days of dietary supplementation …”

The Rabbit Model of Accelerated Atherosclerosis: A Methodological Perspective of the Iliac Artery Balloon Injury

“…. The balloon-injury rabbit iliac artery model has been used to study the effect of new therapeutic agents, novel drug delivery systems, plaque evolution and imaging 10,32,33 .Single or multiple balloon injurieshave been performed in the iliac artery 34,35 , carotid artery 36,37 ,and aorta 10,38 . The advantages of the presented method are the development of large plaque volume and thickness as compared to use of carotid artery.…”