Effects of using Different Reconstruction Algorithms on Coronary Motion Artifacts at Various Heart Rates during Coronary CT Angiography: A Phantom Experiment

Objective: We assessed coronary motion artifacts at various heart rates (HRs) using coronary computed tomography angiography (CCTA) and a phantom; the resulting data were reconstructed using half-scan reconstruction algorithms (HSRA), multi-sector reconstruction algorithms (MSRA), and a novel vendor-specific motion correction algorithm (MCA) introduced to eliminate coronary motion artifacts. Materials and Methods: Using retrospective electrocardiographic (ECG)-gated helical CCTA scans of a cardiac phantom that included branching coronary artery models filled with iodine contrast medium and pulsating at HRs of 50 to 100 beats per minute (bpm), we reconstructed images using HSRA, MSRA, and HSRA combined with MCA during both systole and diastole. On axial images, 2 readers graded image quality focused on coronary motion artifacts at 50 to 100 bpm in 9 segments of the models using a scale from 1 (poor) to 5 (excellent). We then compared the average scores among the 3 algorithms using Kruskal-Wallis and post-hoc tests. Results: At 50 to 60 bpm, there were no significant differences in image quality among the 3 algorithms (P > 0.05). At 70 to 100 bpm, the image quality using MSRA was comparable or better than that of HSRA, and HSRA combined with MCA provided a comparable or better image quality compared with the other 2 algorithms. Conclusion: Coronary motion artifacts are comparable or significantly reduced using HSRA combined with MCA, compared with MSRA.