Reproducibility of coronary calcification detection with electron-beam computed tomography

Abstract

If coronary calcification scores obtained with electron-beam computed tomography (EBT) were proved to be correlated to coronary atherosclerosis, the reproducibility of the technique had to be assessed before being used for patient follow-up. A total of 150 patients, selected as a result of a cholesterol screening programme, were studied by EBT. Twelve contiguous 3-mm-thick transverse slices beginning on the proximal coronary arteries were obtained through the base of the heart. The amount of calcium was evaluated as the calcified area weighted by a coefficient depending on the density peak level. The value was expressed as a logarithmic scale. Intra-observer, inter-observer and inter-examination reproducibilities were calculated. They were 1.9, 1.3 and 7.2%, respectively. These results were good enough to allow the use of EBT for longitudinal studies. The influence of acquisition and calculation conditions on score computation were also analysed.

Detection and quantification of coronary artery calcification with electron-beam and conventional CT

“…In contrast to that, inter-examination reproducibility of the calcium score based on the Agatston method is known to be reduced by partial volume effects and ECG misregistration [16]. In the literature, different authors calculated a variability of 29 % [17], 37.2 % [18], and 46 % [19] for repeated coronary calcium scanning with the EBCT.…”

Coronary Artery Calcium Scoring With Multislice Computed Tomography

“…16 As a quantitative tool for screening and follow-up studies, high levels of accuracy and reproducibility are crucial for coronary calcium scoring. 9,23,24 Moreover, no artificial lesions caused by high image noise should be added to the measurements, since in coronary screening the question whether the patient has any calcified plaques or not is of major prognostic importance. 25 The misinterpretation of image noise as calcium deposits could mean a misclassification of an actually healthy individual into a cardiovascular risk group, which might include unnecessary diagnostic measures or even therapy.…”

Update on using coronary calcium screening by computed tomography to measure risk for coronary heart disease

“…Using such techniques, Shields et al [70] reported a reliability coefficient of 0.99 in 50 subjects who underwent EBCT CAC scanning, and Hernigou et al [69] reported an inter-examination error rate of 7.2% using sequential scanning. Bielak et al [76] reported no differences in CAC prevalence or measured mean CAC areas between dual scans.…”

“…While the correlation between inter-and intra-observer measurements are excellent (r % 0.99) [55,[68][69][70][71], inter-scan variability has been problematic, particularly when encountering patients with lower concentrations or small foci of CAC.…”