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

Author

Dhungel, A. ; Zhen Qian ; Vazquez, G. ; Rinehart, Sarah ; Weeks, M. ; Voros, S.

Author_Institution

Piedmont Heart Inst., Atlanta, GA, USA

fYear

2012

fDate

Aug. 28 2012-Sept. 1 2012

Firstpage

4982

Lastpage

4985

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.

Keywords

blood vessels; computerised tomography; image reconstruction; image registration; medical image processing; statistical analysis; 320-detector row CT; 3D computed tomography; CAC measurement; artery calcium measurement; attenuation cutoff threshold; attenuation values; calcium data; calcium quantification; calcium volume; isotropic CAC images; isotropic CT calcium scans; multidetector-row CT scanners; noninvasive low-radiation method; optimal cutoff threshold; radiofrequency backscatter; registered intravascular ultrasound; size 3 mm; slice thickness; statistical analysis; Accuracy; Arteries; Attenuation; Calcium; Computed tomography; Correlation; Sensitivity; Algorithms; Calcinosis; Coronary Artery Disease; Humans; Image Interpretation, Computer-Assisted; Pattern Recognition, Automated; Radio Waves; Reproducibility of Results; Scattering, Radiation; Sensitivity and Specificity; Subtraction Technique; Tomography, X-Ray Computed; Ultrasonography, Interventional;

fLanguage

English

Publisher

ieee

Conference_Titel

Engineering in Medicine and Biology Society (EMBC), 2012 Annual International Conference of the IEEE

Conference_Location

San Diego, CA

ISSN

1557-170X

Print_ISBN

978-1-4244-4119-8

Electronic_ISBN

1557-170X

Type

conf

DOI

10.1109/EMBC.2012.6347111

Filename

6347111