title: Prospectively ECG-triggered high-pitch coronary angiography with third-generation dual-source CT at 70 kVp tube voltage: feasibility, image quality, radiation dose, and effect of iterative reconstruction.
abstract: BACKGROUND
  Low tube voltage reduces radiation exposure in coronary CT angiography (CTA). Using 70 kVp tube potential has so far not been possible because CT systems were unable to provide sufficiently high tube current with low voltage.
  
  
  OBJECTIVE
  We evaluated feasibility, image quality (IQ), and radiation dose of coronary CTA using a third-generation dual-source CT system capable of producing 450 mAs tube current at 70 kVp tube voltage.
  
  
  METHODS
  Coronary CTA was performed in 26 consecutive patients with suspected coronary artery disease, selected for body weight <100 kg and heart rate <60 beats/min. High-pitch spiral acquisition was used. Filtered back projection (FBP) and iterative reconstruction (IR) algorithms were applied. IQ was assessed using a 4-point rating scale (1 = excellent, 4 = nondiagnostic) and objective parameters.
  
  
  RESULTS
  Mean age was 62 ± 9 years (46% males; mean body mass index, 27.7 ± 3.8 kg/m(2); mean heart rate, 54 ± 5 beats/min). Mean dose-length product was 20.6 ± 1.9 mGy × cm; mean estimated effective radiation dose was 0.3 ± 0.03 mSv. Diagnostic IQ was found in 365 of 367 (FBP) and 366 of 367 (IR) segments (P nonsignificant). IQ was rated "excellent" in 53% (FBP) and 86% (IR) segments (P = .001) and "nondiagnostic" in 2 (FBP) and 1 segment (IR) (P nonsignificant). Mean IQ score was lesser in FBP vs IR (1.5 ± 0.4 vs 1.1 ± 0.2; P < .001). Image noise was lower in IR vs FBP (60 ± 10 HU vs 74 ± 8 HU; P < .001).
  
  
  CONCLUSIONS
  In patients <100 kg and with a regular heart rate <60 beats/min, third-generation dual-source CT using high-pitch spiral acquisition and 70 kVp tube voltage is feasible and provides both robust IQ and very low radiation exposure.
authors.affiliation: Department of Cardiology, University of Erlangen, Erlangen, Germany. Electronic address: michaela.hell@uk-erlangen.de.
authors.forename: Michaela M
authors.initials: MM
authors.lastname: Hell
authors.affiliation: Department of Cardiology, University of Erlangen, Erlangen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bittner
authors.affiliation: Department of Cardiology, University of Erlangen, Erlangen, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Schuhbaeck
authors.affiliation: Department of Cardiology, University of Erlangen, Erlangen, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Muschiol
authors.affiliation: Department of Radiology, University of Erlangen, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Brand
authors.affiliation: Department of Radiology, University of Erlangen, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lell
authors.affiliation: Department of Radiology, University of Erlangen, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Uder
authors.affiliation: Department of Cardiology, University of Erlangen, Erlangen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Achenbach
authors.affiliation: Department of Cardiology, University of Erlangen, Erlangen, Germany.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Marwan
mesh_terms: D000368:Aged; D055424:Cardiac-Gated Imaging Techniques; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005240:Feasibility Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed
keywords: Dual-source CT; High-pitch spiral acquisition; Image quality; Iterative reconstruction; Ultra-low dose coronary CT angiography