Variability of repeated coronary artery calcium measurements by 1.25-mm- and 2.5-mm-thickness images on prospective electrocardiograph-triggered 64-slice CT

Abstract

High reproducibility on coronary artery calcium scoring is a key requirement in monitoring the progression of coronary atherosclerosis. The purpose of this prospective study is to assess the reproducibility of 1.25-mm- and 2.5-mm-thickness images on prospective electrocardiograph-triggered 64-slice CT with respect to 2.5-mm-thickness images on spiral overlapping reconstruction. One hundred patients suspected of coronary artery disease were scanned twice repeatedly, both on prospective electrocardiograph-triggered step-and-shoot and retrospective electrocardiograph-gated spiral scans. Using 1.25-mm-thickness collimation, 1.25-mm- and 2.5-mm-thickness image sets on prospective scans and 2.5-mm-thickness image sets with 1.25-mm increment (overlapping) on retrospective scans were obtained. Coronary artery calcium scores, interscan variability and interobserver variability were evaluated. The mean interscan variability in coronary artery calcium measurement on 1.25-mm prospective/2.5-mm prospective/2.5-mm overlapping retrospective scans were Agatston: 10%/18%/12%, volume: 10%/12%/10% and mass: 8%/13%/11% for observer 1 and Agatston: 8%/14%/10%, volume: 7%/9%/10% and mass: 7%/10%/9% for observer 2, respectively. The mean interobserver variability was 5% to 14%. In conclusion, prospective electrocardiograph-triggered 64-slice CT using the 1.25-mm prospective scan shows the lowest variability. The 2.5-mm prospective scan on volume or mass scoring shows variability of around 10%, comparable to 2.5-mm-thickness spiral overlapping reconstruction images.

Assessment of coronary artery calcium by using volumetric 320-row multi-detector computed tomography: comparison of 0.5 mm with 3.0 mm slice reconstructions

“…However, it was also reported that the increase in detection threshold lead to false-negative scoring results in 6 patients [29]. Similar results of improved calcium detection with thinner slices were found for other studies [9, 22, 31, 32]. However, these studies analysed the effect of thin-slice reconstructions predominantly in patients with positive calcium scores, whereas in the present study, the effect of thin-slice reconstructions focused on 100 patients with and 100 patients without coronary calcium at standard 3.0 mm reconstructions.…”

“…For calculating the Agatston score, a weighing factor is applied based on the peak attenuation within a calcified lesion. This may lead to a higher variability than with the volume score or calcium mass [9]. However, large clinical risk stratification studies are based on the Agatston score [3, 4, 10].…”

Coronary Arterial Calcification on Low-Dose Ungated MDCT for Lung Cancer Screening: Concordance Study with Dedicated Cardiac CT

“…First, CAC scoring on low-dose ungated MDCT scans may not be familiar to most CAC readers. We found, however, that with a training session, interobserver variability was not particularly high compared with that reported for regular cardiac CT [22,23]. Second, it is unknown whether our findings can be reproduced on scanners made by other manufacturers.…”

Considerations in Calcium Scoring Using Multi‐Detector Computed Tomography

“…The same effect was also observed in studies with 16‐slice MDCT comparing 1–3 mm (38). Reduced measurement errors were also reported for 0.625 compared with 1.25 and 2.5 mm slice thickness using 16‐slice MDCT (29).…”