title: Estimated radiation dose reduction using adaptive statistical iterative reconstruction in coronary CT angiography: the ERASIR study.
abstract: OBJECTIVE
  The objective of our study was to assess the impact of Adaptive Statistical Iterative Reconstruction (ASIR) on radiation dose and study quality for coronary CT angiography (CTA).
  
  
  METHODS
  We prospectively evaluated 574 consecutive patients undergoing coronary CTA at three centers. Comparisons were performed between consecutive groups initially using filtered back projection (FBP) (n = 331) and subsequently ASIR (n = 243) with regard to patient and scan characteristics, radiation dose, and diagnostic study quality.
  
  
  RESULTS
  There was no difference between groups in the use of prospective gating, tube voltage, or scan length. The examinations performed using ASIR had a lower median tube current than those obtained using FBP (median [interquartile range], 450 mA [350-600] vs 650 mA [531-750], respectively; p < 0.001). There was a 44% reduction in the median radiation dose between the FBP and ASIR cohorts (4.1 mSv [2.3-5.2] vs 2.3 mSv [1.9-3.5]; p < 0.001). After adjustment for scan settings, ASIR was associated with a 27% reduction in radiation dose compared with FBP (95% CI, 21-32%; p < 0.001). Despite the reduced current, ASIR was not associated with a difference in adjusted signal, noise, or signal-to-noise ratio (p = not significant). No differences existed between FBP and ASIR for interpretability per coronary artery (98.5% vs 99.3%, respectively; p = 0.12) or per patient (96.1% vs 97.1%, p = 0.65). CONCLUSION. ASIR enabled reduced tube current and lower radiation dose in comparison with FBP, with preserved signal, noise, and study interpretability, in a large multicenter cohort. ASIR represents a new technique to reduce radiation dose in coronary CTA studies.
authors: Department of Radiology and Department of Medicine, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada. jleipsic@providencehealth.bc.ca
authors: Jonathon
authors: J
authors: Leipsic
authors: Troy M
authors: TM
authors: Labounty
authors: Brett
authors: B
authors: Heilbron
authors: James K
authors: JK
authors: Min
authors: G B John
authors: GB
authors: Mancini
authors: Fay Y
authors: FY
authors: Lin
authors: Carolyn
authors: C
authors: Taylor
authors: Allison
authors: A
authors: Dunning
authors: James P
authors: JP
authors: Earls
mesh_terms: D016009:Chi-Square Distribution; D003287:Contrast Media; D017023:Coronary Angiography / Q000592:standards*; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011446:Prospective Studies; D011829:Radiation Dosage; D011835:Radiation Protection; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012984:Software; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000592:standards*; D014283:Triiodobenzoic Acids
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol