Abstract 18892: Carbon Nanotube Micro-Computed Tomography Imaging of Myocardial Infarction using Delayed Contrast Enhancement
Purpose: Evaluation of murine cardiac models using micro-CT techniques has been severely limited due to extreme imaging requirements. Unlike conventional x-ray tubes, carbon nanotube (CNT) based sources enables the precise generation and control of x-ray pulses, which can minimize physiological motion. We demonstrate the application of our custom free-breathing prospectively gated CNT micro-CT by evaluating a myocardial infarction model with a delayed contrast enhancement technique.
Materials and Methods: Myocardial infarction was induced in 8 wild-type, 30g male mice. This ischemia reperfusion model was achieved by surgically occluding the LAD artery for 30 minutes followed by 24 hours of reperfusion. Tail vein catheters were placed for contrast administration. Gaseous anesthesia was delivered without the need for intubation. Respiratory and cardiac signals were monitored externally and used to gate the scan. Micro-CT scans were reconstructed to 80-micron voxel size. Iohexol 300mgI/mL was administered followed by images obtained in diastole. Iodinated lipid blood pool contrast agent was then administered, followed with images at systole and diastole. After imaging, the heart was harvested, cut into 1mm slices and stained with TTC. Post-processing analysis was performed using Osirix.
Results: All eight animals survived surgery and the minimally invasive imaging protocol. All subjects demonstrated obvious delayed contrast enhancement in the left ventricular wall following the Iohexol injection. The blood pool contrast agent revealed changes in cardiac function quantified by 3-D volume ejection fractions. All subjects demonstrated areas of myocardial infarct in the LAD distribution on both TTC staining and CNT micro-CT imaging.
Conclusions: The CNT micro-CT system allows for straightforward, free-breathing, prospectively-gated 3-D murine cardiac imaging. We demonstrate the ability to consistently identify areas of myocardial infarct in mice as well as provide functional cardiac information through the use of a delayed contrast enhancement technique. CNT micro-CT provides a powerful new tool for the study of cardiovascular biology.
- © 2010 by American Heart Association, Inc.