X-ray-Based 3D Histology of Murine Hearts Using Contrast-Enhanced Microfocus Computed Tomography (CECT) and Cryo-CECT

Abstract

Cardiovascular diseases are the most common cause of death worldwide, and they still have dramatic consequences on the patients’ lives. Murine models are often used to study the anatomical and microstructural changes caused by the diseases. Contrast-enhanced microfocus computed tomography (CECT) is a new imaging technique for 3D histology of biological tissues. In this study, we confirmed the nondestructiveness of Hf-WD 1:2 POM-based CECT and cryogenic CECT (cryo-CECT) to image the heart in 3D. The influence of the image quality (i.e., acquisition time and spatial resolution) was assessed for the characterization of the heart structural constituents: heart integrity, the coronary blood vessels and the heart valves. Coronary blood vessels were visualized and segmented in murine hearts, allowing us to distinguish veins from arteries and to visualize the 3D spatial distribution of the right coronary artery and the left main coronary artery. Finally, to demonstrate the added value of 3D imaging, the thickness distribution of the two leaflets in the mitral valve and three cusps in the aortic valve was computed in 3D. This study corroborates the added value of CECT and cryo-CECT compared to classical 2D histology to characterize ex vivo the structural properties of murine hearts and paves the way for the detailed 3D (micro)structural analyses of future cardiovascular disease models obtained in mice and rats.

Keywords

• 3D histology
• murine heart
• CECT
• cryo-CECT
• coronary blood vessels
• heart valves