Coronary Artery Stenoses: Accuracy of 64-Detector Row CT Angiography in Segments With Mild, Moderate, or Severe Calcification–A Subanalysis of the CORE-64 Trial

OBJECTIVES: To evaluate the influence of cross-sectional arc calcification on the diagnostic accuracy of computed tomography (CT) angiography compared with conventional coronary angiography for the detection of obstructive coronary artery disease (CAD).

METHODS: Institutional Review Board approval and written informed consent were obtained from all centers and participants for this HIPAA-compliant study. Overall, 4511 segments from 371 symptomatic patients (279 men, 92 women; median age 61 [IQR:53-67]) with clinical suspicion of CAD from the CORE-64 multicenter study were included in the analysis. Two independent blinded observers evaluated the percentage of diameter stenosis and the circumferential extent of calcium (arc calcium). The accuracy of quantitative multidetector CT angiography to depict substantial (≥50%) stenoses was assessed by using quantitative coronary angiography (QCA). Cross-sectional arc calcium was rated on a segment level as follows: noncalcified or mild (<90°), moderate (90°-180°), or severe (>180°) calcification. Univariable and multivariable logistic regression, receiver operation characteristic curve, and clustering methods were used for statistical analyses.

RESULTS: A total of 1099 segments had mild calcification, 503 had moderate calcification, 338 had severe calcification, and

2571 segments were noncalcified. Calcified segments were highly associated (P < .001) with disagreement between CTA and QCA in multivariable analysis after controlling for sex, age, heart rate, and image quality. The prevalence of CAD was 5.4% in noncalcified segments, 15.0% in mildly calcified segments, 27.0% in moderately calcified segments, and 43.0% in severely calcified segments. A significant difference was found in area under the receiver operating characteristic curves (noncalcified: 0.86, mildly calcified: 0.85, moderately calcified: 0.82, severely calcified: 0.81; P < .05).

CONCLUSIONS: In a symptomatic patient population, segment-based coronary artery calcification significantly decreased agreement between multidetector CT angiography and QCA to detect a coronary stenosis of at least 50%.


PMID: 21828192

Posted in Computed Tomography and tagged , , , , , , .


  1. Good paper, with a good number of patients! The findings further attest to the limitations of CCTA in patients with heavily calcified vessels.

    Interesting concept of using cross-sectional analysis of the vessel and the circumferential extent of calcified plaque (arc calcification). Interestingly, although the grading system for the degree of arc calcification appears quite straight-forward, only a good agreement was observed between the readers in the assessment of segment calcium burden (κ = 0.65).

  2. Recently, my hospital bought a 500 Slice Cardiac CT . What’s the difference between 500 and 64 Slice Cardiac CT?

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