title: Comparison of image quality of 64-slice multidetector CT coronary CT angiography using automated and manual multiphase methods for the determination of optimal phases for image reconstruction in patients with various mean heart rates.
abstract: This study aimed to compare the effects of the automated and manual methods for determining the optimal phase of image reconstruction with the use of 64-slice coronary CT angiography (CCTA). In 63 patients, the optimal trigger delay was determined using an automated technique (PhaseXact) and by manual phase selection from the images reconstructed at a 10 ms and 1% increment of the R-R interval. The image quality was evaluated using four-step grading. The mean heart rate in all the patients was 70 +/- 10.1 bpm (range: 52-98 bpm). The frequency of obtaining diagnostic quality images was highest with the manual absolute timing method (97.6% of 753 segments), while it was 94.7% with manual relative timing and 91.9% with an automated method. The mean image quality score (1.3 +/- 0.2) based on the manual absolute timing was significantly better (P = 0.002, one-way ANOVA; P < 0.05, Scheffe's test) than the scores determined with the use of the other two techniques (manual relative timing, 1.4 +/- 0.3; automated method, 1.5 +/- 0.4). The best quality coronary CT images were obtained using image reconstruction with manual absolute timing for the ECG-trigger delay, while an automated method and manual relative timing provided diagnostic quality images in most of the segments.
authors.affiliation: Department of Radiology, Konyang University School of Medicine, Daejeon, Korea.
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Cho
authors.forename: Yeon Hyeon
authors.initials: YH
authors.lastname: Choe
authors.forename: Moo-Sik
authors.initials: MS
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D057205:Automation, Laboratory; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D013997:Time Factors; D036542:Tomography, Spiral Computed