Predicting success of prospective and retrospective gating with dual-source coronary computed tomography angiography: development of selection criteria and initial experience.
BACKGROUND
Prospectively gated coronary computed tomographic angiography (CCTA) with dual-source CT allows substantial reduction of radiation exposure but requires prospective single-phase selection and assessment of likelihood of adequate image quality.


OBJECTIVE
We developed and tested the model for predicting success of prospectively gated CCTA.


METHODS
Retrospectively gated CCTA was acquired with dual-source CT in 162 patients. Two cardiologists assessed by consensus whether diagnostic quality images could have been obtained in a single predefined phase, 70% of R-R interval (70P), thereby identifying patients in whom a prospectively gated scan at 70P would have been successful. Logistic regression models were built with and without a coronary calcium scan. The obtained criteria were applied on 42 additional patients.


RESULTS
By logistic regression, heart rate before CCTA of >or=70 beats/min, maximal heart rate variation before CCTA of >or=10 beats/min, coronary calcium score >or= 400 U, and body mass index (in kg/m(2)) >or= 30 were independent predictors of unsuccessful prospectively gated CCTA using 70P. Excluding coronary calcium score from the model, these same variables in addition to age > 65 years were found to be predictors of unsuccessful prospectively gated CCTA. Applying this model to 42 additional patients, using prospective gating, only 5 segments in 4 patients were nondiagnostic. Mean radiation dose for prospectively gated CCTA was 2.2 +/- 0.8 mSv.


CONCLUSIONS
Prospectively gated CCTA with dual-source CT can be successfully implemented with consideration of prescan heart rate, heart rate variability, body mass index, and coronary calcium score.
Gutstein
Ariel
A
Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA. gutsteina@cshs.org
Wolak
Arik
A
Lee
Cynthia
C
Dey
Damini
D
Ohba
Muneo
M
Suzuki
Yasuyuki
Y
Cheng
Victor
V
Gransar
Heidi
H
Suzuki
Shoji
S
Friedman
John
J
Thomson
Louise E
LE
Hayes
Sean
S
Pimentel
Raymond
R
Paz
William
W
Slomka
Piotr
P
Berman
Daniel S
DS
D002140:California / Q000453:epidemiology; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011379:Prognosis; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*