Cardiac computed tomography prior to atrial fibrillation ablation: Effects of technological advances and protocol optimization

Abstract

Abstract Introduction and Objectives Cardiac computed tomography (CT) can provide a precise three-dimensional anatomic map and exclude intracardiac thrombus prior to atrial fibrillation (AF) ablation. We aimed to assess the impact of CT protocol optimization and technological advances on contrast and radiation doses and on image quality. Methods From a prospective registry of consecutive patients who underwent cardiac CT in a single center, 270 patients were selected in whom CT was performed for assessment prior to AF ablation, divided into three groups: Group 1: the first 150 patients included; Group 2: the last 60 patients assessed with the same CT scanner; Group 3: the first 60 exams performed with a new CT scanner. The quality of the protocol was evaluated based on radiation dose, contrast volume used, the need for a second (delayed) scan, and quantitative image quality analysis (signal-to-noise and contrast-to-noise ratios and the density homogeneity ratio between the left atrium and the left atrial appendage). Results Significant reductions were found in radiation and contrast doses between the first and last subgroups (Group 1: 5.6 mSv and 100 ml; Group 2: 1.3 mSv and 90 ml; Group 3: 0.6 mSv and 65 ml). Although radiation and contrast doses in Group 3 were lower, quantitative measures of image quality were still better (signal-to-noise 13.5; contrast-to-noise 14.8; density homogeneity ratio 0.92). Conclusion Protocol optimization and technological advances both contributed to significantly lower radiation dose and contrast volume used in cardiac CT prior to AF ablation, without compromising image quality.