RESUMO
OBJECTIVE: The aim of this study was to compare image quality and radiation dose of coronary computed tomography (CT) angiography performed with dual-source CT scanner using 2 different protocols in patients with atrial fibrillation. METHODS: Forty-seven patients with AF underwent 2 different acquisition protocols: double high-pitch (DHP) spiral acquisition and retrospective spiral acquisition. The image quality was ranked according to a qualitative score by 2 experts: 1, no evident motion; 2, minimal motion not influencing coronary artery luminal evaluation; and 3, motion with impaired luminal evaluation. A third expert solved any disagreement. RESULTS: A total of 732 segments were evaluated. The DHP group (24 patients, 374 segments) showed more segments classified as score 1 than the retrospective spiral acquisition group (71.3% vs 37.4%). Image quality evaluation agreement was high between observers (κ = 0.8). There was significantly lower radiation exposure for the DHP group (3.65 [1.29] vs 23.57 [10.32] mSv). CONCLUSIONS: In this original direct comparison, a DHP spiral protocol for coronary CT angiography acquisition in patients with atrial fibrillation resulted in lower radiation exposure and superior image quality compared with conventional spiral retrospective acquisition.
