Mean glandular dose coefficients (DgN) for x-ray spectra used in contemporary breast imaging systems. (7th September 2015)

• Record Type: Journal Article
• Authors: Nosratieh, Anita; Hernandez, Andrew; Shen, Sam Z; Yaffe, Martin J; Seibert, J Anthony; Boone, John M
• Is Part Of: Physics in medicine & biology. Volume 60:Number 18(2015:Sep.)
• Page Start: 7179
• Page End: 7190
• Publication Date: 2015-09-07
• Subjects: mammography -- normalized glandular dose -- digital breast tomosynthesis; Biophysics -- Periodicals; Medical physics -- Periodicals; 610.153
• DOI: 10.1088/0031-9155/60/18/7179
• Languages: English
• ISSNs: 0031-9155

Abstract

Abstract: To develop tables of normalized glandular dose coefficients for a range of anode–filter combinations and tube voltages used in contemporary breast imaging systems. Previously published mono-energetic values were used with various spectra to mathematically compute coefficients. The tungsten anode spectra from TASMICS were used; molybdenum and rhodium anode-spectra were generated using MCNPX Monte Carlo code. The spectra were filtered with various thicknesses of Al, Rh, Mo or Cu. An initial half value layer (HVL) calculation was made using the anode and filter material. A range of the HVL values was produced with the addition of small thicknesses of polymethyl methacrylate (PMMA) as a surrogate for the breast compression paddle, to produce a range of HVL values at each tube voltage. Using a spectral weighting method, coefficients for the generated spectra were calculated for breast glandular densities of 0%, 12.5%, 25%, 37.5%, 50% and 100% for a range of compressed breast thicknesses from 3 to 8 cm. Eleven tables of normalized glandular dose ( ) coefficients were produced for the following anode/filter combinations: W + 50 μ m Ag, W + 500 μ m Al, W + 700 μ m Al, W + 200 μ m Cu, W + 300 μ m Cu, W + 50 μ m Rh, Mo + 400 μ m Cu, Mo + 30 μ m Mo, Mo + 25 μ m Rh, Rh + 400 μ m Cu and Rh + 25 μ m Rh. Where possible, these results were compared to previously published values and were found to be on average less than 2% different than previously reported values. Over 200 pages of coefficients were computed for modeled x-ray system spectra that are used in a number of new breast imaging applications. The reported values were found to be in excellent agreement when compared to published values.