Mammography spectrum measurement using an x-ray diffraction device.
The use of a diffraction spectrometer developed by Deslattes for the determination of mammographic kV is extended to the measurement of accurate, relative x-ray spectra. Raw x-ray spectra (photon fluence versus energy) are determined by passing an x-ray beam through a bent quartz diffraction crystal, and the diffracted x-rays are detected by an x-ray intensifying screen coupled to a charge coupled device. Two nonlinear correction procedures, one operating on the energy axis and the other operating on the fluence axis, are described and performed on measured x-ray spectra. The corrected x-ray spectra are compared against tabulated x-ray spectra measured under nearly identical conditions. Results indicate that the current device is capable of producing accurate relative x-ray spectral measurements in the energy region from 12 keV to 40 keV, which represents most of the screen-film mammography energy range. Twelve keV is the low-energy cut-off, due to the design geometry of the device. The spectrometer was also used to determine the energy-dependent x-ray mass attenuation coefficients for aluminium, with excellent results in the 12-30 keV range. Additional utility of the device for accurately determining the attenuation characteristics of various normal and abnormal breast tissues and phantom substitutes is anticipated.
Boone
J M
JM
Department of Radiology, University of California, Davis, UC Davis Medical Center, Sacramento 95817, USA. jmboone@ucdavis.edu
Yu
T
T
Seibert
A
A
D055592:Biophysical Phenomena; D001703:Biophysics; D005260:Female; D006801:Humans; D008327:Mammography / Q000295:instrumentation* / Q000706:statistics & numerical data; D008962:Models, Theoretical; D013679:Technology, Radiologic / Q000295:instrumentation; D014961:X-Ray Diffraction / Q000295:instrumentation*