Time Adaptive Filtration to Reduce Radiation Dose in Coronary CT Angiography

Technology #2012-083

Coronary CT angiography (cCTA) is used to noninvasively look at the arteries that supply the heart muscle with blood, and diagnose (or rule out) blocked arteries, which are the main cause of heart attacks. cCTA is performed with either prospective or retrospective ECG gating. Irrespective of which variant is used, images are reconstructed with projection data corresponding to a partial scan at a given cardiac phase, even if more data before and after the phase of interest was actually acquired. Here, we propose a strategy for cCTA that intends to use the entire dose delivered to the patient to boost the quality of the image reconstructed at a chosen phase. It consists in reconstructing images at multiple cardiac phases neighboring the one of interest, and then applying a time adaptive filter (TAF) that reduces noise but maintains temporal and spatial resolution. Uses are: to reduce doses, improve image quality of phases acquired with lower tube current, increase likelihood of optimal exams when patients have high and/or variable heart rates.