Estimated Radiation Dose Reduction Using Adaptive Statistical Iterative Reconstruction in Coronary CT Angiography: The ERASIR Study

• Published in: American journal of roentgenology (1976) Vol. 195; no. 3; pp. 655 - 660
• Main Authors: Leipsic, Jonathon, LaBounty, Troy M., Heilbron, Brett, Min, James K., Mancini, G. B. John, Lin, Fay Y., Taylor, Carolyn, Dunning, Allison, Earls, James P.
• Format: Journal Article
• Language: English
• Published: Reston, VA American Roentgen Ray Society 01.09.2010
• Subjects: Biological and medical sciences; Cardiovascular system; Chi-Square Distribution; Contrast Media; Coronary Angiography - standards; Coronary Disease - diagnostic imaging; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Linear Models; Male; Medical sciences; Middle Aged; Models, Statistical; Prospective Studies; Radiation Dosage; Radiation Protection; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Radiographic Image Interpretation, Computer-Assisted - methods; Software; Statistics, Nonparametric; Tomography, X-Ray Computed - standards; Triiodobenzoic Acids; coronary CT angiography; Radiation dose; Angiography; Radiodiagnosis; Medical imagery; Computerized axial tomography; Coronary arteriography; adaptive statistical iterative reconstruction; iterative reconstruction; Angiocomputed tomography
• ISSN: 0361-803X; 1546-3141; 1546-3141
• DOI: 10.2214/AJR.10.4288

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). 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. 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.