CT comparison of visual and computerised quantification of coronary stenosis according to plaque composition

Abstract

Objective To compare the diagnostic performance of computerised quantification with visual assessment for the detection of significant coronary stenosis using MDCT, and to determine the impact of plaque composition on diagnostic procedure. Methods We retrospectively evaluated 1564 coronary segments of 127 patients who underwent 64-slice MDCT and quantitative coronary angiography (QCA). The lesions were analysed with both methods of visual assessment and computerised quantification using an automatic vessel contour detection tool, and the results were compared with the QCA results. Plaques detected with MDCT were classified as calcified, mixed, and non-calcified according to plaque composition. Results The sensitivity and PPV of visual assessment (computerised quantification) were 95% (86%) and 76% (81%), respectively. Bland-Altman analysis demonstrated a mean difference of −5.2±21.6% for all lesions, 2.2±23.7 for calcified plaques, and −12.0±17.2% for non-calcified plaques. The correlation coefficients and limits of agreement between CTA and QCA were 0.48 and ±46.5% (0.74 and ±33.7%) in the lesions with calcified plaques (noncalcified plaques). ConclusionsThe computerised quantification decreases the sensitivity due to underestimation of non-calcified plaques compared with visual assessment, and had a poorer correlation and a larger limit of agreement in the lesions with calcified plaque compared with non-calcified plaques.

Reproducibility of quantitative coronary computed tomography angiography in asymptomatic individuals and patients with acute chest pain

“…The greater volumes of lower density plaque in populations with greater likelihood of CAD would, therefore, not only result in poor reproducibility of non-calcified plaque but also of geometrical, distributional, burden and volume related parameters. This is exemplified by the findings of Kang et al who reported a decreased sensitivity to detect diameter stenosis >50% in non-calcified plaque due to underestimation when using automated techniques compared with visual assessments[25]. Furthermore, increased disease burden potentially requires greater manual correction when using semi-automated quantification techniques, thereby introducing greater variability into QCT measurements.…”

Reliability and Accuracy of Simple Visual Estimation in Assessment of Peripheral Arterial Stenosis

“…Several previous studies examined the accuracy of SVE using a small number of readers reviewing a large number of images (11)(12)(13); however, these studies did not involve readers across several subspecialties, which limits their findings from being widely applicable. Also, the accuracy of estimation in relation to physician experience is unknown.…”

Non-diagnostic coronary artery calcification and stenosis: a correlation of coronary computed tomography angiography and invasive coronary angiography

“…An automatic vessel detection tool on curved multi-planar reconstructions and cross-sectional images perpendicular to the vessel was used to initially segment the coronary artery, as described previously (9). Two cardiologists blinded to the clinical and ICA data (GL and WT, with at least 5 years of experience in cardiovascular CT imaging and ICA) first evaluated the cCTA images to determine if the segments containing calcium were interpretable and graded the stenosis severity at the site of calcification.…”

“…Non-diagnostic CAC was defined as a totally calcified plaque or predominantly calcified plaque (plaque with less than 50% non-calcified component), in which significant luminal narrowing (>50%) could not be entirely excluded by the cCTA reader solely due to a potential blooming artifact (no signs of motion, streak, or windmill artifacts, incomplete coverage, or increase background noise levels). An automatic vessel detection tool on curved multiplanar reconstructions and cross-sectional images perpendicular to the vessel was used to initially segment the coronary artery, as described previously (9). Two cardiologists blinded to the clinical and ICA data (GL and WT, with at least 5 years of experience in cardiovascular CT imaging and ICA) first evaluated the cCTA images to determine if the segments containing calcium were interpretable and graded the stenosis severity at the site of calcification.…”