Extending the concept of weighted CT dose index to elliptical phantoms of various aspect ratios

Andrey Markovich; Ashraf G. Morgan; Frank F. Dong; Andrew N. Primak; Xiang Li

doi:10.1117/1.JMI.4.3.031205

5 July 2017 Extending the concept of weighted CT dose index to elliptical phantoms of various aspect ratios

Andrey Markovich, Ashraf G. Morgan, Frank F. Dong, Andrew N. Primak, Xiang Li

Author Affiliations +

Journal of Medical Imaging, Vol. 4, Issue 3, 031205 (July 2017). https://doi.org/10.1117/1.JMI.4.3.031205

Abstract

The purpose of this study was to extend the concept of weighted CT dose index ( CTDI w ) to the elliptical phantoms. Based on the published body dimension data, eight body aspect ratios were chosen between 1 (perfectly circular) and 1.72 (extremely elliptical). For each aspect ratio, two elliptical cylinders were created digitally to represent adult and pediatric bodies. Their cross-sectional areas were identical to the standard 32- and 16-cm CTDI phantoms. For each phantom, CTDI 100 at center and periphery were simulated for tube voltages between 70 and 140 kVp using a validated Monte Carlo program. The simulations also provided the average dose over the cross-sectional area, CTDI xsec . Values of CTDI xsec and CTDI 100 allowed linear systems of equations to be established, from which central and peripheral weighting coefficients were solved. Regardless of phantom shape, only two weighting coefficients were needed: w 1 for the central CTDI 100 and w 2 for the average of the four peripheral CTDI 100

Citation Download Citation

Andrey Markovich, Ashraf G. Morgan, Frank F. Dong, Andrew N. Primak, and Xiang Li "Extending the concept of weighted CT dose index to elliptical phantoms of various aspect ratios," Journal of Medical Imaging 4(3), 031205 (5 July 2017). https://doi.org/10.1117/1.JMI.4.3.031205

Received: 29 March 2017; Accepted: 12 June 2017; Published: 5 July 2017

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