Share Email Print
cover

Proceedings Paper

Organ dose conversion coefficients for tube current modulated CT protocols for an adult population
Author(s): Wanyi Fu; Xiaoyu Tian; Pooyan Sahbaee; Yakun Zhang; William Paul Segars; Ehsan Samei
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

In computed tomography (CT), patient-specific organ dose can be estimated using pre-calculated organ dose conversion coefficients (organ dose normalized by CTDIvol, h factor) database, taking into account patient size and scan coverage. The conversion coefficients have been previously estimated for routine body protocol classes, grouped by scan coverage, across an adult population for fixed tube current modulated CT. The coefficients, however, do not include the widely utilized tube current (mA) modulation scheme, which significantly impacts organ dose. This study aims to extend the h factors and the corresponding dose length product (DLP) to create effective dose conversion coefficients (k factor) database incorporating various tube current modulation strengths. Fifty-eight extended cardiac-torso (XCAT) phantoms were included in this study representing population anatomy variation in clinical practice. Four mA profiles, representing weak to strong mA dependency on body attenuation, were generated for each phantom and protocol class. A validated Monte Carlo program was used to simulate the organ dose. The organ dose and effective dose was further normalized by CTDIvol and DLP to derive the h factors and k factors, respectively. The h factors and k factors were summarized in an exponential regression model as a function of body size. Such a population-based mathematical model can provide a comprehensive organ dose estimation given body size and CTDIvol. The model was integrated into an iPhone app XCATdose version 2, enhancing the 1st version based upon fixed tube current modulation. With the organ dose calculator, physicists, physicians, and patients can conveniently estimate organ dose.

Paper Details

Date Published: 31 March 2016
PDF: 15 pages
Proc. SPIE 9783, Medical Imaging 2016: Physics of Medical Imaging, 97833E (31 March 2016); doi: 10.1117/12.2217271
Show Author Affiliations
Wanyi Fu, Carl E. Ravin Advanced Imaging Labs. (United States)
Duke Univ. (United States)
Xiaoyu Tian, Carl E. Ravin Advanced Imaging Labs. (United States)
Duke Univ. (United States)
Pooyan Sahbaee, Carl E. Ravin Advanced Imaging Labs. (United States)
North Carolina State Univ. (United States)
Yakun Zhang, Carl E. Ravin Advanced Imaging Labs. (United States)
Duke Univ. (United States)
William Paul Segars, Carl E. Ravin Advanced Imaging Labs. (United States)
Duke Univ. (United States)
Ehsan Samei, Carl E. Ravin Advanced Imaging Labs. (United States)
Duke Univ. (United States)


Published in SPIE Proceedings Vol. 9783:
Medical Imaging 2016: Physics of Medical Imaging
Despina Kontos; Thomas G. Flohr, Editor(s)

© SPIE. Terms of Use
Back to Top