RESUMO
Small angle X-ray scattering (SAXS) images of normal breast tissue and benign and malignant breast tumour tissues, fixed in formalin, were measured at the momentum transfer range of 0.063 nm(-1) < or = q (= 4pisin(theta/2)/lambda) < or = 2.720 nm(-1). Four intrinsic parameters were extracted from the scattering profiles (1D SAXS image reduced) and, from the combination of these parameters, another three parameters were also created. All parameters, intrinsic and derived, were subject to discriminant analysis, and it was verified that parameters such as the area of diffuse scatter at the momentum transfer range 0.50 < or = q < or = 0.56 nm(-1), the ratio between areas of fifth-order axial and third-order lateral peaks and third-order axial spacing provide the most significant information for diagnosis (p < 0.001). Thus, in this work it was verified that by combining these three parameters it was possible to classify human breast tissues as normal, benign lesion or malignant lesion with a sensitivity of 83% and a specificity of 100%.
Assuntos
Neoplasias da Mama/patologia , Espalhamento a Baixo Ângulo , Difração de Raios X , Adulto , Idoso , Mama/citologia , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/metabolismo , Análise Discriminante , Formaldeído/metabolismo , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Adulto JovemRESUMO
Mamografia é o mais eficiente método de se detectar alguns casos de câncer de mama antes que sejam clinicamente palpáveis. Esta detecção, muitas vezes, é prejudicada pelo espalhamento porque este influi de maneira deletérica sobre o contraste. O propósito deste trabalho é quantificar este efeito e a dose média glandular, para uma composição mamária 50/50 por cento, diferente kVp e espessuras de mamas. Os resultados obtidos apresentam uma diminuição do contraste com o aumento da kVp e da espessura; um aumento da dose média glandular com o aumento da espessura e uma diminuição com o aumento da kVp.
Mammography has the potential to detect breast cancer before they become clinically palpable. Under some conditions the images are affected by scattered radiation reducing the contras!. The objective of this study is to quantify this effect and the average glandular dose as a function of kVp and breast thickness for breast composition 50/50%. The results show that the contrast decreases with increasing kVp and breast thickness, and the average glandular dose increases with increasing breast thickness and decreases with increasing kVp.