Importance of the heart rate in ultra-high-resolution coronary CT angiography with 0.35 s gantry rotation time

• Published in: Japanese journal of radiology Vol. 40; no. 8; pp. 781 - 790
• Main Authors: Kojima, Tsukasa, Shirasaka, Takashi, Yamasaki, Yuzo, Kondo, Masatoshi, Hamasaki, Hiroshi, Mikayama, Ryoji, Sakai, Yuki, Kato, Toyoyuki, Nishie, Akihiro, Ishigami, Kousei, Yabuuchi, Hidetake
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.08.2022; Springer Nature B.V
• Subjects: Angiography; Computed tomography; Coronary artery; Heart rate; High resolution; Image quality; Imaging; Medical imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Original Article; Radiology; Radiotherapy; Sharpness; Heart rate; Motion artifact; Ultra-high-resolution computed tomography; Coronary computed tomography angiography; Coronary artery
• DOI: 10.1007/s11604-022-01265-2
• ISSN: 1867-1071

Purpose We investigated the effects of the heart rate (HR) on the motion artifact in coronary computed tomography angiography (CCTA) with ultra-high-resolution-CT (U-HRCT), and we clarified the upper limit of optimal HR in CCTA with U-HRCT in a comparison with conventional-resolution-CT (CRCT) on a cardiac phantom and in patients with CCTA. Materials and methods A pulsating cardiac phantom equipped with coronary models was scanned at static and HR simulations of 40–90 beats/min (bpm) at 10-bpm intervals using U-HRCT and CRCT, respectively. The sharpness and lumen diameter of the coronary model were quantitatively compared between U-HRCT and CRCT stratified by HR in the phantom study. We also assessed the visual inspections of clinical images in CCTA with U-HRCT. Results At the HRs ≤ 60 bpm, the error of the lumen diameter of the U-HRCT tended to be smaller than that of the CRCT. However, at the HRs > 60 bpm, the inverse was shown. For the image sharpness, the U-HRCT was significantly superior to the CRCT ( p  < 0.05). In the visual assessment, the scores were negatively correlated with HRs in patients (Spearman r  =  − 0.71, p  < 0.01). A receiver-operating characteristic analysis revealed the HR of 61 bpm as the optimal cutoff of the non-diagnostic image quality, with an area under the curve of 0.87, 95% sensitivity, and 71% specificity. Conclusion At HRs ≤ 60 bpm, U-HRCT was more accurate in the imaging of coronary arteries than CRCT. The upper limit of the optimal HR in CCTA with U-HRCT was approx. 60 bpm.