Optimal cutoff threshold for calcium quantification in isotropic CT calcium scans by validating against registered intravascular ultrasound with radiofrequency backscatter

Annu Int Conf IEEE Eng Med Biol Soc. 2012:2012:4982-5. doi: 10.1109/EMBC.2012.6347111.

Abstract

3D Computed Tomography (CT) provides noninvasive, low-radiation method of coronary artery calcium (CAC) measurement. Conventional CAC images are acquired on multidetector-row CT scanners without contrast, and reconstructed with 3 mm slice thickness. The calcium volume is quantified by registering voxels with attenuation values greater than or equal to 130 Hounsfield Unit (HU). In isotropic CAC images with 0.5 mm slice thickness obtained from 320-detector row CT, the optimal value of attenuation cutoff threshold is unknown. In this paper we find the optimal cutoff threshold for calcium quantification in isotropic CT calcium scans by validating against registered intravascular ultrasound with radiofrequency backscatter (IVUS/VH). From the statistical analysis of calcium data obtained from the images of 9 patients we found a range of optimal thresholds and the conventional threshold of 130 HU was in the range. Further, the optimal values were different for individual patients.

Publication types

  • Evaluation Study
  • Validation Study

MeSH terms

  • Algorithms
  • Calcinosis / complications
  • Calcinosis / diagnosis*
  • Coronary Artery Disease / complications
  • Coronary Artery Disease / diagnosis*
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Pattern Recognition, Automated / methods*
  • Radio Waves
  • Reproducibility of Results
  • Scattering, Radiation
  • Sensitivity and Specificity
  • Subtraction Technique*
  • Tomography, X-Ray Computed / methods*
  • Ultrasonography, Interventional / methods*