Reproducibility of coronary plaque detection and characterization using low radiation dose coronary computed tomographic angiography in patients with intermediate likelihood of coronary artery disease (ReSCAN study)

Abstract

The purpose of this study is to evaluate the interscan, interobserver and intraobserver agreement for coronary plaque detection, and characterization using low radiation dose high-pitch spiral acquisition coronary CT angiography (CTA). Two experienced observers independently evaluated coronary CTA datasets from 50 consecutive patients undergoing two 128-slice dual source CT scans within 12 days. Mean (±SD) estimated radiation exposure was 1.5 ± 0.2 mSv per scan. Observers recorded the presence and characterization of coronary plaques as non-calcified or calcified. A "segment involvement score" (SIS) was computed by summing the numbers of segments with any coronary plaque per patient. Reproducibility was assessed using kappa (κ) statistics, paired t test and Bland-Altman analyses. Interscan, interobserver, and intraobserver agreement (κ-values) for detection of any or calcified plaques were 83-94% (κ-values 0.57-0.85), and 67-84% (0.31-0.67) for non-calcified plaques on a patient level. No significant difference was observed in mean interscan or interobserver SIS. Mean (95% CI) intraobserver SIS difference was -0.88 (-1.25; -0.51), P < 0.001, with limits of agreement from -4.7 to 2.9. Low radiation dose high-pitch coronary CTA permits detection of any or calcified plaques with high interscan, interobserver, intraobserver agreement. However, variability for the detection of non-calcified plaque is substantial.

Interobserver agreement for the detection of atherosclerotic plaque in coronary CT angiography: comparison of two low-dose image acquisition protocols with standard retrospectively ECG-gated reconstruction

“…The results obtained are similar to those of previous smaller studies. Ovrehus et al showed an interobserver agreement of 81% to identify the presence of atherosclerotic plaque -95% for calcified plaque and 82% for non-calcified plaque -in 50 patients examined with prospectively ECG-triggered high pitch spiral acquisition [30]. Similar to our study, Cohen's kappa indicated moderately close interobserver agreement for atherosclerotic plaque (κ 00.57 vs. κ 00.48).…”

Interscan reproducibility of quantitative coronary plaque volume and composition from CT coronary angiography using an automated method

“…Bland-Altman analyses still reveal relatively wide limits of agreement, which could partially be attributed to differences in image quality between two examinations for the same patients and could further be potentially alleviated by further improvements in software, including automated detection of lesions. [38]. Patients were examined twice with a mean imaging interval of 5±3 days.…”

“…Accurate and reproducible quantitative measurements of coronary plaque volume may play a role in serial studies to determine disease progression or response to medical therapies [18]. Data on interscan reproducibility of coronary plaque detection are provided by two studies; so far they are limited to qualitative measurements in one study [38] and to manual quantitative measurements by two experienced observers in another [39]. Thus, our aim was to evaluate the interscan reproducibility of quantitative measurements of coronary plaque volume and composition from coronary CTA, using a standardized automated method.…”

CT coronary angiography: impact of adapted statistical iterative reconstruction (ASIR) on coronary stenosis and plaque composition analysis

“…In addition to depicting luminal narrowing CCTA allows early detection of coronary atherosclerotic lesions [4,5]. Several attempts have been made to characterize the plaque nature by differentiating non-calcified from calcified and mixed plaques with CCTA [6,7].…”