Anatomical and functional cardiac PCCT imaging pipeline for characterization of Apolipoprotein E mouse models
Non-invasive imaging strategies are essential in understanding the factors associated with the ongoing rise in cardiovascular disease (CVD) and Alzheimer’s disease (AD), and the possible interactions between these diseases. Our scientific premise is based on the role of the APOE gene where APOE4 is considered a risk factor for CVD and AD. This study incorporates the use of novel apolipoprotein E mouse models with a humanized innate immune system, through mNos2 KO and presence of the human NOS2 gene (APOE4/HN and APOE3/HN), together with the more traditional APOE (-/-) mice. We have imaged these models for CVD and AD with a cardiac photon-counting CT (PCCT) imaging pipeline to characterize their cardiac anatomy and function. The pipeline, consisting of contrast enhanced in vivo PCCT imaging, accurate intrinsic cardiac gating, temporally resolved multi-energy iterative reconstruction, spectral decomposition, 3D cardiac segmentation, and ex vivo, high-resolution PCCT imaging allowed for quantitative analysis and comparison of cardiac function as well as identification of anatomical irregularities such as calcified aortic plaques. Our analysis finds no statistically significant differences in cardiac functional metrics or the aortic diameter in these APOE mouse models. Future work will focus on optimizing the image reconstruction to reduce the computation time and on using staining for ex vivo PCCT imaging of the vascular system in these models.
