title: High-pitch dual-source CT coronary angiography: systolic data acquisition at high heart rates.
abstract: OBJECTIVE
  To assess the effect of systolic data acquisition for electrocardiography (ECG)-triggered high-pitch computed tomography (CT) on motion artefacts of coronary arteries in patients with high heart rates (HRs).
  
  
  METHODS
  Eighty consecutive patients (15 women, age 67 ± 14 years) with HR ≥ 70 bpm underwent CT angiography of the thoracic aorta (CTA) on 128-slice dual-source CT in ECG-triggered high-pitch acquisition mode (pitch = 3.2) set at 60% (group A, n = 40) or 30% (group B, n = 40) of the RR interval. Two blinded readers graded coronary artery image quality on a three-point scale. Radiation doses were calculated.
  
  
  RESULTS
  Inter-observer agreement in grading image quality of the 1,154 coronary segments was good (κ = 0.62). HRs were similar in groups A and B (85 ± 13 bpm vs 85 ± 14 bpm, p not significant). Significantly fewer coronary segments with non-diagnostic image quality occurred (i.e. score 3) in group B than in group A [2.8% (16/579) vs 8.3% (48/575), p < 0.001]. Seventeen patients (42.5%) of group A and 12 patients (30.0%) of group B had at least one non-diagnostic segment. Effective radiation doses were 2.3 ± 0.3 mSv for chest CTA.
  
  
  CONCLUSIONS
  A systolic acquisition window for high-pitch dual-source CTA in patients with high HRs (≥ 70 bpm) significantly improves coronary artery image quality at a low radiation dose.
authors.affiliation: Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors.forename: Robert
authors.initials: R
authors.lastname: Goetti
authors.forename: Gudrun
authors.initials: G
authors.lastname: Feuchtner
authors.forename: Paul
authors.initials: P
authors.lastname: Stolzmann
authors.forename: Lotus
authors.initials: L
authors.lastname: Desbiolles
authors.forename: Michael Alexander
authors.initials: MA
authors.lastname: Fischer
authors.forename: Christoph
authors.initials: C
authors.lastname: Karlo
authors.forename: Stephan
authors.initials: S
authors.lastname: Baumueller
authors.forename: Hans
authors.initials: H
authors.lastname: Scheffel
authors.forename: Hatem
authors.initials: H
authors.lastname: Alkadhi
authors.forename: Sebastian
authors.initials: S
authors.lastname: Leschka
mesh_terms: D000368:Aged; D016477:Artifacts; D055424:Cardiac-Gated Imaging Techniques; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement; D013599:Systole; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide