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Author Notes:

Ioannis Sechopoulos, Department of Radiology and Winship Cancer Institute, Emory University School of Medicine, 1701 Upper Gate Drive NE, Suite 5018, Atlanta, Georgia 30322; phone: (404)712–2412; fax: (404)712‐5813; email: E-mail address:isechop@emory.edu

Subjects:

Keywords:

  • Science & Technology
  • Life Sciences & Biomedicine
  • Radiology, Nuclear Medicine & Medical Imaging
  • tomosynthesis
  • dosimetry
  • Monte Carlo
  • breast
  • mammography
  • FLAT-PANEL DETECTOR
  • DIGITAL TOMOSYNTHESIS
  • SYSTEM
  • MAMMOGRAPHY
  • EXPERIENCE

Glandular radiation dose in tomosynthesis of the breast using tungsten targets

Tools:

Journal Title:

Journal of Applied Clinical Medical Physics

Volume:

Volume 9, Number 4

Publisher:

, Pages 161-171

Type of Work:

Article | Final Publisher PDF

Abstract:

With the advent of new detector technology, digital tomosynthesis imaging of the breast has, in the past few years, become a technique intensely investigated as a replacement for planar mammography. As with all other x-ray-based imaging methods, radiation dose is of utmost concern in the development of this new imaging technology. For virtually all development and optimization studies, knowledge of the radiation dose involved in an imaging protocol is necessary. A previous study characterized the normalized glandular dose in tomosynthesis imaging and its variation with various breast and imaging system parameters. This characterization was performed with x-ray spectra generated by molybdenum and rhodium targets. In the recent past, many preliminary patient studies of tomosynthesis imaging have been reported in which the x-ray spectra were generated with x-ray tubes with tungsten targets. The differences in x-ray distribution among spectra from these target materials make the computation of new normalized glandular dose values for tungsten target spectra necessary. In this study we used previously obtained monochromatic normalized glandular dose results to obtain spectral results for twelve different tungsten target x-ray spectra. For each imaging condition, two separate values were computed: the normalized glandular dose for the zero degree projection angle (D g N 0 ), and the ratio of the glandular dose for non-zero projection angles to the glandular dose for the zero degree projection (the relative glandular dose, RGD(α)). It was found that D g N 0 is higher for tungsten target x-ray spectra when compared with D g N 0 values for molybdenum and rhodium target spectra of both equivalent tube voltage and first half value layer. Therefore, the D g N 0 for the twelve tungsten target x-ray spectra and different breast compositions and compressed breast thicknesses simulated are reported. The RGD(a) values for the tungsten spectra vary with the parameters studied in a similar manner to that found for the molybdenum and rhodium target spectra. The surface fit equations and the fit coefficients for RGD(a) included in the previous study were also found to be appropriate for the tungsten spectra.

Copyright information:

© 2008 The Authors.

This is an Open Access work distributed under the terms of the Creative Commons Attribution 3.0 Unported License (http://creativecommons.org/licenses/by/3.0/).

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