title: Effect of a novel motion correction algorithm (SSF) on the image quality of coronary CTA with intermediate heart rates: segment-based and vessel-based analyses.
abstract: OBJECTIVE
  To evaluate the effect of SnapShot Freeze (SSF) reconstruction at an intermediate heart-rate (HR) range (65-75bpm) and compare this method with single-sector reconstruction and bi-sector reconstruction on segmental and vessel bases in retrospective coronary computed tomography angiography (CCTA).
  
  
  METHODS
  Retrospective electrocardiogram-gated CCTA was performed on 37 consecutive patients with HR between 65 and 75bpm using a 64-row CT scanner. Retrospective single-sector reconstruction, bi-sector reconstruction, and SSF were performed for each patient. Multi-phase single-sector reconstruction was performed to select the optimal phase. SSF and bi-sector images were also reconstructed at the optimal phase. The images were interpreted in an intent-to-diagnose fashion by two experienced readers using a 5-point scale, with 3 points as diagnostically acceptable. Image quality among the three reconstruction groups were compared on per-patient, per-vessel, and per-segment bases.
  
  
  RESULTS
  The average HR of the enrolled patients was 69.4±2.7bpm. A total of 111 vessels and 481 coronary segments were assessed. SSF provided significantly higher interpretability of the coronary segments than bi-sector reconstructions. The qualified and excellent rates of SSF (97.9% and 82.3%) were significantly higher than those of single-sector (92.9% and 66.3%) and bi-sector (90.9% and 64.7%) reconstructions. The image quality score (IQS) using SSF was also significantly higher than those of single-sector and bi-sector reconstructions both on per-patient and per-vessel bases. On per-segment analysis, IQS was improved in most segments (9/14).
  
  
  CONCLUSIONS
  The SSF algorithm can provide acceptable diagnostic image quality in coronary CTA for patients with intermediate HR.
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: qianwen18@126.com.
authors.forename: Qianwen
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: lipyu818@gmail.com.
authors.forename: Pengyu
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: suzhuangzhi@xwh.ccmu.edu.cn.
authors.forename: Zhuangzhi
authors.initials: Z
authors.lastname: Su
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: 314985151@qq.com.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Yao
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: wy19851121@126.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: fskwangchen@gmail.com.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: duxying_xw@163.com.
authors.forename: Xiangying
authors.initials: X
authors.lastname: Du
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: kuncheng.li@gmail.com.
authors.forename: Kuncheng
authors.initials: K
authors.lastname: Li
mesh_terms: D000465:Algorithms; D017023:Coronary Angiography / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
keywords: Coronary CT angiography; Image quality; Motion correction algorithm; Segmental reconstruction