title: Effect of a standardized radiation dose reduction protocol on diagnostic accuracy of coronary computed tomographic angiography.
abstract: Although numerous strategies for radiation dose decrease in coronary computed tomographic angiography are effective, their combined impact on diagnostic performance is not known. We therefore assessed the effect of a standardized coronary computed tomographic angiographic protocol on diagnostic accuracy. We evaluated 80 consecutive patients from 3 sites with coronary computed tomographic angiography and quantitative coronary angiography. All sites initially used nonstandardized protocols; 2 sites then initiated a standardized protocol, and 1 site continued its nonstandardized protocol as a time-overlapping control. Two blinded readers interpreted coronary computed tomographic angiographic studies; a third obtained consensus. A blinded core laboratory performed quantitative coronary angiography. Each segment was graded as <50% or > or =50% diameter stenosis. Compared to those using nonstandardized protocols (n = 35), studies using standardized protocols (n = 45) had a trend to increased use of prospective gating (p = 0.09), lower voltage (p <0.01), decreased current (p <0.01), and shorter scan length (p <0.01). Median (interquartile range) radiation dose decreased from 5.7 mSv (4.0 to 10.8) to 2.0 mSv (1.3 to 3.4, p <0.001). There were no significant differences in sensitivity (100%, 20 of 20, vs 100%, 18 of 18, p = 1.0), specificity (93%, 14 of 15, vs 85%, 23 of 27, p = 0.61), or accuracy (97%, 34 of 35, vs 91%, 41 of 45, p = 0.27) by patient; sensitivity (83%, 33 of 40, vs 83%, 25 of 30, p = 0.93), specificity (92%, 86 of 93, vs 92%, 134 of 146, p = 0.85), or accuracy (89%, 119 of 133, vs 90%, 159 of 176, p = 0.80) by artery; or sensitivity (80%, 44 of 55, vs 72%, 26 of 36, p = 0.74), specificity (94%, 332 of 353, vs 94%, 499 of 531, p = 0.96), or accuracy (92%, 376 of 408, vs 93%, 525 of 567, p = 0.80) by segment. In conclusion, a standardized dose-decrease protocol for coronary computed tomographic angiography decreases radiation dose without affecting diagnostic performance.
authors.affiliation: Department of Medicine, Weill Cornell Medical College, New York, NY, USA. tml9001@med.cornell.edu
authors.forename: Troy M
authors.initials: TM
authors.lastname: LaBounty
authors.forename: Jonathon
authors.initials: J
authors.lastname: Leipsic
authors.forename: G B John
authors.initials: GB
authors.lastname: Mancini
authors.forename: Brett
authors.initials: B
authors.lastname: Heilbron
authors.forename: Smita
authors.initials: S
authors.lastname: Patel
authors.forename: Ella A
authors.initials: EA
authors.lastname: Kazerooni
authors.forename: Baskaran
authors.initials: B
authors.lastname: Sundaram
authors.forename: Fay Y
authors.initials: FY
authors.lastname: Lin
authors.forename: Allison
authors.initials: A
authors.lastname: Dunning
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Saltzman
authors.forename: Giora
authors.initials: G
authors.lastname: Weisz
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Weinsaft
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Choi
authors.forename: Sunaina
authors.initials: S
authors.lastname: Koduru
authors.forename: James K
authors.initials: JK
authors.lastname: Min
mesh_terms: D000328:Adult; D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*