Cardiac micro-computed tomography for morphological and functional phenotyping of muscle LIM protein null mice.

The purpose of this study was to investigate the use of micro-computed tomography (micro-CT) for morphological and functional phenotyping of muscle LIM protein (MLP) null mice and to compare micro-CT with M-mode echocardiography. MLP null mice and controls were imaged using both micro-CT and M-mode echocardiography. For micro-CT, we used a custom-built scanner. Following a single intravenous injection of a blood pool contrast agent (Fenestra VC, ART Advanced Research Technologies, Saint-Laurent, QC) and using a cardiorespiratory gating, we acquired eight phases of the cardiac cycle (every 15 ms) and reconstructed three-dimensional data sets with 94-micron isotropic resolution. Wall thickness and volumetric measurements of the left ventricle were performed, and cardiac function was estimated. Micro-CT and M-mode echocardiography showed both morphological and functional aspects that separate MLP null mice from controls. End-diastolic and -systolic volumes were increased significantly three- and fivefold, respectively, in the MLP null mice versus controls. Ejection fraction was reduced by an average of 32% in MLP null mice. The data analysis shows that two imaging modalities provided different results partly owing to the difference in anesthesia regimens. Other sources of errors for micro-CT are also analyzed. Micro-CT can provide the four-dimensional data (three-dimensional isotropic volumes over time) required for morphological and functional phenotyping in mice.

Duke Scholars

Author Cristian Tudorel Badea Radiology

Author Lan Mao Medicine, Cardiology

Author Howard Allan Rockman Medicine, Cardiology

Author G. Allan Johnson Radiology