Abstract 999: Gated Micro Computed Tomography Scanning: An Emerging Tool for Longitudinal Assessment of Murine Cardiac Remodeling.

Abstract

Background: Recent advances in high energy X-ray source computed tomography (CT) technology have made it possible to accurately image murine cardiac structure and function. We describe the use of a gated Micro CT system to assess cardiac remodeling in a murine model of myocardial infarction (MI). Methods: Adult FVB mice (n = 10) were randomized to surgically induced MI by left coronary artery ligation or sham procedure. Dual gated cardiac and respiratory Micro CT scans were performed pre-operatively and at weeks 4, 8 and 12 post-procedure. End-diastolic and end-systolic images were acquired by gating on the ECG P-and S’-waves, respectively. Post-acquisition analysis was performed using image analysis software and the following parameters were quantified: left ventricular (LV) volume and mass, right ventricular volume and mass, right and left atrial volumes, and ventricular ejection fraction (EF). Results: Images were successfully acquired with a resolution of 100 microns allowing for identification and quantification of key cardiac structures (Fig 1A ). Following MI, animals exhibited left ventricular failure with significantly increased* end systolic and diastolic volumes by week 4. Ventricular dilation continued through week 8, plateauing by week 12. Left ventricular mass increased steadily over 12 weeks*, with a significantly decreased* LVEF of 28.0 ± .05% by week 12 (pre-MI: 66.7 ± .06%,*p < 0.01). Post-MI left ventricular change is detailed in Fig 1B . Conclusions: MicroCT scanning can be successfully used to characterize murine myocardial structure and function, making it a useful tool to assess cardiac phenotypes and models of cardiovascular disease.