Author + information
- Annika Schuhbaeck,
- Yuka Otaki,
- Stephan Achenbach,
- Christian Schneider,
- Franziska Hecker,
- Johannes Rixe,
- Piotr Slomka,
- James Min,
- Daniel Berman and
- Damini Dey
When coronary calcium scoring is performed in patients undergoing contrast-enhanced coronary computed tomographic angiography (CTA), a separate non-contrast scan is acquired before CTA. The purpose of our study was to develop and validate an automated method for calculating a coronary calcium score from single coronary CTA.
We analyzed coronary CTA and non-contrast CT data sets (Dual Source CT, 2 × 64 × 0.6mm collimation) of 84 patients (55 males, mean 66±11 years) with an Agatston score > 0 on non-contrast CT. Images were acquired in two experienced centers (University Hospital of Gießen, Germany and Cedars Sinai Medical Center, USA). Coronary calcium score on non-contrast CT was measured using commercial methods. Total coronary calcium volume was measured on coronary CTA using an automated method with scan-specific calcium thresholds (Autoplaq). For calcium scoring on coronary CTA, consecutive datasets were split into derivation (N=40) and validation groups (N=44). To calculate the calcium score on coronary CTA, a conversion factor between calcium scores measured on non-contrast CT and calcium volumes measured on coronary CTA was derived by linear regression (derivation group). Accuracy of this technique was validated by systematic comparison with non-contrast CT scores (validation group).
In coronary CTA, the mean lumen attenuation was 331.0±55.8 HU and the mean lower calcium threshold was 562.0±96.2 HU. In the validation group, the mean calculated calcium score derived from coronary CTA was 547±695 and 491±612 in non-contrast images (p=0.12, mean absolute difference between contrast-enhanced and non-contrast images 121±204). The calculated calcium score showed an excellent correlation with the calcium score from non-contrast images (Pearson r = 0.95). In the validation group, 39 out of 44 patients (88.6%) were classified into the same standard category (1-10, 11-100, 101-400 or >400) with a weighted ? of 0.87.
Coronary calcium score can be accurately measured from contrast-enhanced coronary CTA by using an automated, standardized method, obviating the need for a non-contrast scan.
Poster Sessions, Expo North
Saturday, March 09, 2013, 3:45 p.m.-4:30 p.m.
Session Title: Imaging: CT/Multimodality III
Abstract Category: 20. Imaging: CT/Multimodality
Presentation Number: 1181-345
- 2013 American College of Cardiology Foundation