| The detection and diagnosis of breast disease is an important part of health care delivery. I want to know whether one could successfully characterize a breast biopsy sample by measuring its x-ray diffraction signature. I have built an energy dispersive x-ray diffraction system in order to characterize breast tissues. The diffractometer is used in conjunction with a semianalytic model to extract the differential linear scattering coefficients, mu s(x), of breast tissues. These coefficients describe the probabilities of scatter events occuring per unit length of the tissue per unit solid angle of detection. They are a function of the momentum transfer argument, x = sin(theta/2)/lambda, that combines the dependence of scatter on the scatter angle theta and the photon wavelength lambda. I validated the technique by using a 3 mm diameter 50 kV polychromatic x-ray beam incident on a 5 mm diameter 5 mm thick sample of water. My ensemble average compares very well with the gold standard. Without applying a correction for the detector's response I obtain a reduced chi-square c2n = 26 while with a response c2n = 15. This difference is not significant and therefore I conclude that a correction is not required. My preliminary measurements of breast tissue are also encouraging. (Abstract shortened by UMI.)... |
