title: The Impact of Different Levels of Adaptive Iterative Dose Reduction 3D on Image Quality of 320-Row Coronary CT Angiography: A Clinical Trial.
abstract: OBJECTIVE
  The aim of this study was the systematic image quality evaluation of coronary CT angiography (CTA), reconstructed with the 3 different levels of adaptive iterative dose reduction (AIDR 3D) and compared to filtered back projection (FBP) with quantum denoising software (QDS).
  
  
  METHODS
  Standard-dose CTA raw data of 30 patients with mean radiation dose of 3.2 ± 2.6 mSv were reconstructed using AIDR 3D mild, standard, strong and compared to FBP/QDS. Objective image quality comparison (signal, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contour sharpness) was performed using 21 measurement points per patient, including measurements in each coronary artery from proximal to distal.
  
  
  RESULTS
  Objective image quality parameters improved with increasing levels of AIDR 3D. Noise was lowest in AIDR 3D strong (p ≤ 0.001 at 20/21 measurement points; compared with FBP/QDS). Signal and contour sharpness analysis showed no significant difference between the reconstruction algorithms for most measurement points. Best coronary SNR and CNR were achieved with AIDR 3D strong. No loss of SNR or CNR in distal segments was seen with AIDR 3D as compared to FBP.
  
  
  CONCLUSIONS
  On standard-dose coronary CTA images, AIDR 3D strong showed higher objective image quality than FBP/QDS without reducing contour sharpness.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT00967876.
authors.affiliation: Department of Radiology, Charité Medical School, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Feger
authors.affiliation: Department of Radiology, Charité Medical School, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Rief
authors.affiliation: Department of Radiology, Charité Medical School, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Zimmermann
authors.affiliation: Department of Radiology, Charité Medical School, Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Martus
authors.affiliation: Toshiba Medical Systems Europe B.V., Zoetermeer, the Netherlands.
authors.forename: Joanne Désirée
authors.initials: JD
authors.lastname: Schuijf
authors.affiliation: Toshiba Medical Systems Europe B.V., Zoetermeer, the Netherlands.
authors.forename: Jörg
authors.initials: J
authors.lastname: Blobel
authors.affiliation: Department of Radiology, Charité Medical School, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany; Department of Medical Statistics, Informatics and Documentation, University Hospital of Friedrich-Schiller University Jena, Jena, Germany.
authors.forename: Felicitas
authors.initials: F
authors.lastname: Richter
authors.affiliation: Department of Radiology, Charité Medical School, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Dewey
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D059629:Signal-To-Noise Ratio; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media