Coronary Artery Calcium Scoring on Low-dose Prospective Electrocardiographically-triggered 64-Slice CT

Horiguchi, Jun; Matsuura, Noriaki; Yamamoto, Hideya; Kiguchi, Masao; Fujioka, Chikako; Kitagawa, Toshiro; Kohno, Nobuoki; Ito, Katsuhide

doi:10.1016/j.acra.2008.05.017

« Previous Next »Academic Radiology
Volume 16, Issue 2 , Pages 187-193, February 2009

Coronary Artery Calcium Scoring on Low-dose Prospective Electrocardiographically-triggered 64-Slice CT1

Jun Horiguchi, MD
- Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima, 734-8551 Japan
- Address correspondence to: J.H.
Noriaki Matsuura, MD
- Department of Radiology, Division of Medical Intelligence and Informatics, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
Hideya Yamamoto, MD
- Department of Molecular and Internal Medicine, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
Masao Kiguchi, RT
- Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima, 734-8551 Japan
Chikako Fujioka, RT
- Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima, 734-8551 Japan
Toshiro Kitagawa, MD
- Department of Molecular and Internal Medicine, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
Nobuoki Kohno, MD
- Department of Molecular and Internal Medicine, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
Katsuhide Ito, MD
- Department of Radiology, Division of Medical Intelligence and Informatics, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
- Department of Molecular and Internal Medicine, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan

Received 6 April 2008; accepted 13 May 2008.

Rationale and Objectives

The purpose of this prospective study was to assess image noise and variability in repeated coronary artery calcium (CAC) scoring on low-dose prospective electrocardiographically-triggered 64-slice multidetector computed tomography.

Materials and Methods

Patients (n = 115) suspected of having coronary artery disease were scanned twice, using a tube current of 10 × body mass index mA. The standard deviation (SD) of the computed tomographic value in the ascending aorta and (mean + 2 × SD) were obtained. Repeated CAC scores (Agatston, volume, and mass) were measured by two observers, and the interscan and interobserver variability were determined.

Results

The mean tube current used was 246 ± 36 mA. The mean tube current–time product and mean estimated effective dose were 57 ± 8 mA and 0.9 ± 0.2 mSv, respectively. The SD and (mean + 2 × SD) computed tomographic values in the ascending aorta were 16 ± 3 and 75 ± 10 Hounsfield units, respectively. Repeated CAC scores were correlated (r² = 0.995–0.998). The interscan variability for observer 1 and observer 2, respectively, were 13% and 13% for Agatston score, 12% and 11% for volume, and 11% and 11% for mass. The interobserver variability for scan 1 and scan 2, respectively, were 3% and 3% for Agatston score, 5% and 3% for volume, and 3% and 3% for mass.

Conclusion

Low-dose prospective electrocardiographically-triggered 64-slice multidetector computed tomography shows low interscan and interobserver variability on CAC scoring while maintaining low image noise.

Key Words: CT, coronary artery, calcium, radiation dose, interscan variability, interobserver variability