Calculation of the X-Ray Spectrum of a Mammography System with Various Voltages and Different Anode-Filter Combinations Using MCNP Code

• Main Authors: Lida Gholamkar, Mahdi Sadeghi, Ali Asghar Mowlavi, Mitra Athari
• Format: Article
• Language: English
• Published: Mashhad University of Medical Sciences 2016-09-01
• Series: Iranian Journal of Medical Physics
• Subjects: Anodes; Filters; Full-field digital mammography system; MCNP code; Monte Carlo Method; X-ray spectrum
• Online Access: http://ijmp.mums.ac.ir/article_7959_3f02ff8bc7e7eec1686a1bb491a2abba.pdf

Introduction One of the best methods in the diagnosis and control of breast cancer is mammography. The importance of mammography is directly related to its value in the detection of breast cancer in the early stages, which leads to a more effective treatment. The purpose of this article was to calculate the X-ray spectrum in a mammography system with Monte Carlo codes, including MCNPX and MCNP5. Materials and Methods The device, simulated using the MCNP code, was Planmed Nuance digital mammography device (Planmed Oy, Finland), equipped with an amorphous selenium detector. Different anode/filter materials, such as molybdenum-rhodium (Mo-Rh), molybdenum-molybdenum (Mo-Mo), tungsten-tin (W-Sn), tungsten-silver (W-Ag), tungsten-palladium (W-Pd), tungsten-aluminum (W-Al), tungsten-molybdenum (W-Mo), molybdenum-aluminum (Mo-Al), tungsten-rhodium (W-Rh), rhodium-aluminum (Rh-Al), and rhodium-rhodium (Rh-Rh), were simulated in this study. The voltage range of the X-ray tube was between 24 and 34 kV with a 2 kV interval. Results The charts of changing photon flux versus energy were plotted for different types of anode-filter combinations. The comparison with the findings reported by others indicated acceptable consistency. Also, the X-ray spectra, obtained from MCNP5 and MCNPX codes for W-Ag and W-Rh combinations, were compared. We compared the present results with the reported data of MCNP4C and IPEM report No. 78 for Mo-Mo, Mo-Rh, and W-Al combinations. Conclusion The MCNPX calculation outcomes showed acceptable results in a low-energy X-ray beam range (10-35 keV). The obtained simulated spectra for different anode/filter combinations were in good conformity with the finding of previous research.