Avaliação das curvas de transmissão de feixes de raios X em mamografia digital contrastada

Jeferson Barbosa Marques; Diego Merigue da Cunha

doi:10.29384/rbfm.2021.v15.19849001628

Autores

Jeferson Barbosa Marques Instituto Nacional do Câncer https://orcid.org/0000-0001-6970-2180
Diego Merigue da Cunha Universidade Federal de Uberlândia https://orcid.org/0000-0002-5536-0498

DOI:

https://doi.org/10.29384/rbfm.2021.v15.19849001628

Palavras-chave:

mamografia digital contrastada, Monte Carlo, proteção radiológica, blindagem

Resumo

Imagens mamográficas têm sido cada vez mais importantes na luta contra o câncer de mama. Uma nova técnica de imageamento, denominada mamografia digital contrastada de dupla energia, tem ganhado destaque na avaliação de lesões suspeitas. Essa técnica consiste no uso de um agente contrastante e na exposição da mama em feixes de baixa e alta energia. O objetivo desse trabalho é determinar as curvas de transmissão dos feixes empregados em mamografia digital contrastada, através de diferentes materiais utilizados como blindagem, e seus parâmetros de ajuste α, β e γ. A metodologia foi baseada no método Monte Carlo, utilizando o código PENELOPE. Os resultados mostraram grandes diferenças entre as curvas de transmissão entre os feixes de baixa e alta energia. O parâmetro α diminui com o aumento do potencial do tubo, enquanto β e γ não apresentam uma tendência geral. De modo geral, os resultados obtidos reforçam a importância de se considerar dados de transmissão apropriados para cada técnica de imagem.

Downloads

Não há dados estatísticos.

Referências

1. Karellas A, Vedantham S. Breast cancer imaging: a perspective for the next decade. Med Phys 2008;35(11):4878-97
2. Dromain C, Thibault F, Diekmann F, Fallenberg EM, Jong RA, Koomen M, et al. Dual-energy contrast-enhanced digital mammography: initial clinical results of a multireader, multicase study. Breast Cancer Res 2012;14(3):1-18.
3. James JJ, Tennant SL. Contrast-enhanced spectral mammography (CESM). Clin Radiol 2018;73(8):715-23.
4. Jochelson MS, Dershaw DD, Sung JS, Heerdt AS, Thornton C, Moskowitz CS, et al. Bilateral contrast-enhanced dual-energy digital mammography: feasibility and comparison with conventional digital mammography and MR imaging in women with known breast carcinoma. Radiology 2013;266(3):743-51.
5. Lee-Felker SA, Tekchandani L, Thomas M, Gupta E, Andrews-Tang D, Roth A, et al. Newly diagnosed breast cancer: comparison of contrast-enhanced spectral mammography and breast MR imaging in the evaluation of extent of disease. Radiology 2017;285(2):389-400.
6. Nosratieh A, Hernandez A, Shen SZ, Yaffe MJ, Seibert JA, Boone JM. Mean glandular dose coefficients (DgN) for x-ray spectra used in contemporary breast imaging systems. Phys Med Biol 2015;60(18):7179-90.
7. Jeukens CR, Lalji UC, Meijer E, Bakija B, Theunissen R, Wildberger JE, et al. Radiation exposure of constrast-enhanced spectral mammography compared with full-field digital mammography. Invest Radiol 2014;49(10):659-65.
8. James JR, Pavlicek W, Hanson JA, Boltz TF, Patel BK. Breast radiation dose with CESM compared with 2D FFDM and 3D tomosynthesis mammography. AJR Am J Roentgenol 2017;208(2):362-72.
9. Archer BR, Thornby JI, Bushong SC. Diagnostic x-ray shielding design based on an empirical model of photon attenuation. Health Phys 1983;44(5):507-17.
10. Salvat F, Fernández-Varea JM, Sempau J. PENELOPE-2008: A code system for Monte Carlo simulation of electron and photon transport. Workshop Proceedings. Barcelona, Spain;2008.
11. Cunha DM, Tomal A, Poletti ME. Monte Carlo simulation of x-ray spectra in mammography and contrast-enhanced digital mammography using the code PENELOPE. IEEE Trans Nucl Sci 2013;60(2):495-502.
12. Del Lama LS, Godeli J, Poletti ME. Monte Carlo simulation studies for the determination of microcalcification thickness and glandular ratio through dual-energy mammography. Radiat Phys Chem 2017;137:157-62.
13. Simpkin DJ. Shielding requirements for mammography. Health Phys 1987;53(3):267-79.
14. Li X, Zhang D, Liu B. Transmission of broad W/Rh and W/Al (target/filter) x-ray beams operated at 25–49 kVp through common shielding materials. Med Phys 2012;39(7):4132-38.
15. Archer BR, Fewell TR, Conway BJ, Quinn PW. Attenuation properties of diagnostic x-ray shielding materials. Med Phys 1994;21(9):1499-507.
16. NCRP Report Nº 147. Structural shielding design for medical x-ray imaging facilities. Bethesda, MD: National Council for Radiation Protection and Measurements, 2004.
17. Simpkin DJ. Shielding requirements for constant-potential diagnostic x-ray beams determined by a Monte Carlo calculation. Health Phys 1989;56(2):151-64
18. Huang H, Scaduto DA, Liu C, Yang J, Zhu C, Rinaldi K, et al. Comparison of contrast-enhanced digital mammography and contrast-enhanced digital breast tomosynthesis for lesion assessment. J. Med. Imag. 2019;6(3):031407.
19. Hernandez AM, Seibert JA, Nosratieh A, Boone JM. Generation and analysis of clinically relevant breast imaging x-ray spectra. Med Phys 2017;44(6):2148-60.
20. Simpkin DJ. Transmission data for shielding diagnostic x-ray facilities. Health Phys 1995;68(5):704-9.
21. Hubbell JH, Seltzer SM. Tables of x-ray mass attenuation coefficients and mass energy-absorption coefficients from 1 keV to 20 MeV for elements Z = 1 to 92 and 48 additional substances of dosimetric interest, 2004. Disponível em: https://www.nist.gov/pml/x-ray-mass-attenuation-coefficients. Acesso em 19 fevereiro de 2021.