A phantom study of the effect of heart rate, coronary artery displacement and vessel trajectory on coronary artery calcium score: Potential for risk misclassification

Academic Article


  • Background: Accurate coronary artery calcium scoring improves risk stratification in some strata of the population. Objective: We evaluated individual and combined effects of reader experience, heart rate, vessel displacement, and trajectory on computed tomography (CT) Agatston score, calcium volume, and calcium mass in a cardiac phantom model. Methods: A cardiac motion phantom was scanned with a 64-slice CT scanner with artificial electrocardiogram gating with combinations of the following: heart rates 60, 80, and 100 beat/min; vessel displacement of 1.25 and 2.5 cm; and multiple vessel trajectories of craniocaudal, right-left, anteroposterior, right coronary artery (RCA), left anterior descending, and left circumflex (LCX). Calcium quantification was done by 2 different readers with the use of 3 methods: Agatston, calcium volume, and calcium mass. Results: Heart rate, coronary displacement, and trajectory had significant effects on all 3 techniques, with a general decrease in score as the heart rate increased. A vessel displacement of 2.5 cm decreased the Agatston score by 16% (P < 0.0001) and LCX motion decreased the score by 17% (P < 0.0001). Combined effects often resulted in larger differences; for example, a heart rate of 60 beat/min, vessel displacement of 1.25 cm, and RCA motion resulted in an Agatston score of 907, whereas with a heart rate of 100 beat/min, vessel displacement of 2.5 cm, and LCX motion the score was 604. Conclusion: The calcium score is affected by heart rate, vessel displacement, and trajectory. © 2012 Society of Cardiovascular Computed Tomography.
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    Author List

  • Tigges S; Arepalli CD; Tridandapani S; Oshinski J; Kurz CR; Richer EJ; Chen Z; Stillman AE; Raggi P
  • Start Page

  • 260
  • End Page

  • 267
  • Volume

  • 6
  • Issue

  • 4