Haruhiko Machida MD, Presenter: Nothing to Disclose

Xiao Zhu Lin MD, Abstract Co-Author: Nothing to Disclose

Rika Fukui, Abstract Co-Author: Nothing to Disclose

Yun Shen PhD, Abstract Co-Author: Employee, General Electric Company Researcher, General Electric Company

Isao Tanaka, Abstract Co-Author: Nothing to Disclose

Eiko Ueno MD, Abstract Co-Author: Nothing to Disclose

Takuya Ishikawa, Abstract Co-Author: Nothing to Disclose

Etsuko Tate, Abstract Co-Author: Nothing to Disclose

He Qing Wang MSc, Abstract Co-Author: Nothing to Disclose

To retrospectively investigate the influence of use of a novel motion correction algorithm (MCA) on quality and interpretability of coronary CT angiography (CCTA) images among patients grouped by heart rate (HR).

We divided 105 patients who underwent 64-detector CCTA into 6 groups based on their average HRs (25 with average HR ≤ 59 bpm; 23, 60-64 bpm; 23, 65-69 bpm; 13, 70-74 bpm; 14, 75-79 bpm; and 7, ≥ 80 bpm), and 2 readers independently evaluated quality of axial images of the left main trunk, anterior descending artery, circumflex artery, and right coronary artery (RCA) reconstructed with and without the MCA at 75% of the R-R interval in patients with average HR ≤ 64 bpm and at 40% (systole) and at 75% (diastole) in patients with HR ≥ 65 bpm. For each different HR group and cardiac phase, per-vessel and per-segment image quality regarding motion artifacts was visually graded using a 5-point scale and compared using Wilcoxon signed rank test, and percentages of interpretable image quality (scores, 3-5) were compared between images reconstructed between with the MCA at the diastole with average HR of 65-69 bpm or ≤ 69 bpm and at the systole with HR of 70-79 bpm (the higher or more extensive HR group, respectively) and without the MCA at the diastole with average HR ≤ 64 bpm (the reference group) using chi-square test. We assessed inter-reader agreement of image quality scores by segment using κ-statistics. P < 0.05 was considered statistically significant.

Use of the MCA significantly improved image quality and interpretability in all groups, providing similar or better per-vessel (92-100% or 96-100% versus 88-100%) and per-segment interpretable quality (98% or 99% versus 97%) in the higher or more extensive HR group, respectively, compared to the reference group without significant difference except for the more extensive HR group (P = 0.008 for the RCA, 0.0002 for all segments). The inter-reader agreement was excellent (κ = 0.965).

Quality and interpretability of images of CCTA reconstructed with the MCA were similar or better in patients with average HR ≤ 79 bpm than those of the reference group.

Use of a novel MCA may increase the upper limitation of HR to 79 bpm for use with step-and-shoot scan and reasonably reduce radiation dose compared to retrospectively-gated helical scan.

Machida, H, Lin, X, Fukui, R, Shen, Y, Tanaka, I, Ueno, E, Ishikawa, T, Tate, E, Wang, H, Influence of a Novel Motion Correction Algorithm on Quality and Interpretability of Images of 64-detector Coronary CT Angiography among Patients Grouped by Heart Rate.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14001914.html