AJR:195, September 2010
Jonathon Leipsic, Troy M. LaBounty, Brett Heilbron, James K. Min, G. B.John Mancini, Fay Y.Lin, Carolyn Taylor, Allison Dunning, James P. Earls
OBJECTIVE. The objective of our study was to assess the impact of Adaptive Statisti¬cal Iterative Reconstruction (ASIR) on radiation dose and study quality for coronary CT an-giography (CTA). ,
SUBJECTS AND METHODS. We prospectively evaluated 574 consecutive patients un¬dergoing 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 cur¬rent 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 signifi¬cant). 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 compari¬son with FBP, with preserved signal, noise, and study interpretability, in a large multicenter co-hort. ASIR represents a new technique to reduce radiation dose in coronary CTA studies.