Detailed Description:

Study Description: This is an observational technical development study of advanced mathematical image reconstruction of raw CT data on patients with structural heart disease, in order to create better pictures. The raw CT data are obtained in the course of clinically-indicated contrast-enhanced time-resolved cardiac CT without any change in clinical practice. The raw data are acquired on a specific imaging system (Canon Aquilion One) at the enrolling site(s). Subjects are recruited among candidates selected clinically to undergo time-resolved cardiac CT in the diagnosis and treatment of structural heart disease. After consenting in writing, data are abstracted from their medical record, and the raw CT data used for standard medical care are copied. There is no investigational component to the standard clinical CT data acquisition and there is no change in radiation exposure from standard clinical CT examination. Subject participation concludes at the end of the standard clinical CT examination. The raw CT data are sent with PII to NHLBI investigators who will remove identifiers and replace with a code before transmitting the image to the industry collaborator (Canon) for investigational advanced mathematical image reconstruction. The reconstructed CT images are then transmitted back to the NHLBI where the images are re-identified. The NHLBI investigators will then forward the reconstructed image to the site investigators. The advanced image reconstruction may be performed at NHLBI once adequate computer resources are available. The research analysis consists of a comparison of standard CT images from the enrolling site with the advanced mathematical image reconstructions ("investigational images") for quality metrics. The investigational advanced mathematical image reconstruction kernel may be changed iteratively for the purpose of technical development during this study. The advanced image reconstruction is considered investigational because it is a commercial device not yet cleared for marketing by the US Food and Drug Administration. The advanced image reconstruction yields images with four-fold higher spatial resolution that standard images, based on the same standard CT acquisition. The advanced reconstruction images are labeled investigational and offer potential benefit to research subjects who are also patients. Therefore, the images are labeled investigational and returned to the local physician-investigators, to use at their discretion. This includes the possibility of informing medical decision-making based on investigational higher-resolution images. Objectives: The objective of this research protocol is to determine whether advanced mathematical image reconstructions create superior images compared with standard cardiac CT image reconstruction in patients with structural heart disease. Endpoints: The primary endpoint is a semi-quantitative measure of superiority of advanced mathematical image reconstruction compared with standard cardiac CT image reconstruction for study-specific fine detail. Secondary endpoints include quantitative signal-to-noise (SNR), contrast-to-noise (CNR), and image noise. Exploratory endpoints include Likert-type scales of image noise, artifacts, subjective image contrast, image sharpness, and diagnostic confidence.}}