title: Automatic determination of differential coronary artery motion minima for cardiac computed tomography optimal phase selection.
abstract: OBJECTIVE
  Selecting the optimal phase for coronary artery evaluation can be challenging, especially at higher heart rates, given that the optimal phase may differ for each of the coronary arteries. This study aimed to evaluate a novel vessel-specific algorithm which automatically outputs the minimum motion phase per coronary artery.
  
  
  METHODS
  The study included 44 patients who underwent 256-slice cardiac computed tomography for evaluation of chest pain. End-systolic and mid-diastolic minimal motion phases were automatically calculated by a previously validated global motion algorithm and by a new vessel-specific algorithm which calculates the minimum motion for each of the three main coronary arteries, separately. Two readers blindly evaluated all coronary segments for image quality. Median scores per coronary artery were compared by the Wilcoxon signed rank test.
  
  
  RESULTS
  The variation, per patient, between the optimal phases of the three coronary arteries was 5.0 ± 4.5% (1%-22%) for end systole and 4.8 ± 4.1% (0%-19%) for mid diastole. The mean image quality scores per coronary artery were 4.0 ± 0.61 for the vessel-specific approach and 3.80 ± 0.69 for the global phase selection (P < .001). Overall, 46 of 122 arteries had a better score with the vessel-specific approach and five with the standard global approach. Interreader agreement was substantial (k = 0.72).
  
  
  CONCLUSIONS
  This study has shown that multiple phases are required to ensure optimal image quality for all three coronary arteries and that a vessel-specific phase selection algorithm achieves superior results to the standard global approach.
authors.affiliation: Cardiology Department, Rambam Health Care Campus and Technion, Israel Institute of Technology, Haalita Street, Haifa 3109601, Israel. Electronic address: j_lessick@rambam.health.gov.il.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lessick
authors.affiliation: Klinik für Diagnostische und Interventionelle Radiologie, Ulm, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Klass
authors.affiliation: Klinik für Diagnostische und Interventionelle Radiologie, Ulm, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Wuchenauer
authors.affiliation: Philips Healthcare, Cleveland, Ohio.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Walker
authors.affiliation: Philips Research Laboratories, Hamburg, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Schmitt
authors.affiliation: Philips Research Laboratories, Hamburg, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Peters
authors.affiliation: Philips Research Laboratories, Hamburg, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Weese
authors.affiliation: Klinik für Diagnostische und Interventionelle Radiologie, Ulm, Germany.
authors.forename: Horst
authors.initials: H
authors.lastname: Brunner
authors.affiliation: Philips Healthcare, Cleveland, Ohio.
authors.forename: Mani
authors.initials: M
authors.lastname: Vembar
authors.affiliation: Philips Research Laboratories, Hamburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Grass
authors.affiliation: Cardiology Department, Rambam Health Care Campus and Technion, Israel Institute of Technology, Haalita Street, Haifa 3109601, Israel.
authors.forename: Doron
authors.initials: D
authors.lastname: Aronson
authors.affiliation: Klinik für Diagnostische und Interventionelle Radiologie, Ulm, Germany.
authors.forename: Martin H K
authors.initials: MH
authors.lastname: Hoffmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D003971:Diastole; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D013599:Systole; D014057:Tomography, X-Ray Computed
keywords: Cardiac computed tomography; coronary arteries; coronary artery motion; coronary artery phase selection; image quality