AIMS: Assessment of para-valvular aortic regurgitation remains challenging. Quantitative video-densitometry is an effective technique however overlap of the aorta and left ventricle (LV) limits feasibility. We aimed to develop and validate a method to determine an 'Overlap Free Projection' (OFP).
METHODS AND RESULTS: 65 computed tomography scans of patients referred for transcatheter aortic valve implantation were analysed using 3D reconstruction to evaluate the OFP. We observed that the relative position of the descending aorta to the LV and aortic root determines the OFP and developed a rule based on this data. 81 fluoroscopic cases were assessed for validation. The OFP was determined in a significantly greater proportion of cases that followed the rule compared to those that did not (98% vs. 45%, p<0.001).
CONCLUSIONS: The OFP rule is a straightforward method to reliably determine a patient-specific OFP for contrast aortography.