Dual energy x-ray imaging and scoring of coronary calcium: physics-based digital phantom and clinical studies

Bo Zhou; Di Wen; Katelyn Nye; Robert C. Gilkeson; David L. Wilson

doi:10.1117/12.2217023

31 March 2016 Dual energy x-ray imaging and scoring of coronary calcium: physics-based digital phantom and clinical studies

Bo Zhou, Di Wen, Katelyn Nye, Robert C. Gilkeson, David L. Wilson

Author Affiliations +

Proceedings Volume 9783, Medical Imaging 2016: Physics of Medical Imaging; 978342 (2016) https://doi.org/10.1117/12.2217023
Event: SPIE Medical Imaging, 2016, San Diego, California, United States

Abstract

Coronary artery calcification (CAC) as assessed with CT calcium score is the best biomarker of coronary artery disease. Dual energy x-ray provides an inexpensive, low radiation-dose alternative. A two shot system (GE Revolution-XRd) is used, raw images are processed with a custom algorithm, and a coronary calcium image (DECCI) is created, similar to the bone image, but optimized for CAC visualization, not lung visualization. In this report, we developed a physicsbased, digital-phantom containing heart, lung, CAC, spine, ribs, pulmonary artery, and adipose elements, examined effects on DECCI, suggested physics-inspired algorithms to improve CAC contrast, and evaluated the correlation between CT calcium scores and a proposed DE calcium score. In simulation experiment, Beam hardening from increasing adipose thickness (2cm to 8cm) reduced C_g by 19% and 27% in 120kVp and 60kVp images, but only reduced C_g by <7% in DECCI. If a pulmonary artery moves or pulsates with blood filling between exposures, it can give rise to a significantly confounding PA signal in DECCI similar in amplitude to CAC. Observations suggest modifications to DECCI processing, which can further improve CAC contrast by a factor of 2 in clinical exams. The DE score had the best correlation with "CT mass score" among three commonly used CT scores. Results suggest that DE x-ray is a promising tool for imaging and scoring CAC, and there still remains opportunity for further DECCI processing improvements.

Citation Download Citation

Bo Zhou, Di Wen, Katelyn Nye, Robert C. Gilkeson, and David L. Wilson "Dual energy x-ray imaging and scoring of coronary calcium: physics-based digital phantom and clinical studies", Proc. SPIE 9783, Medical Imaging 2016: Physics of Medical Imaging, 978342 (31 March 2016); https://doi.org/10.1117/12.2217023

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available