Effect of scatter on image quality in synchrotron radiation mammography

Abstract

The display of low-contrast structures and fine microcalcifications is essential for the early diagnosis of breast cancer. In order to achieve a high image quality level with a minimum amount of radiation delivered to the patient, the use of different spectra (Mo or Rh anode and filters) was introduced. The European Synchrotron Radiation Facility is able to produce a monochromatic beam with a high photon flux. It is thus a powerful tool to study the effect of beam energy on image quality and dose in mammography. Our image quality assessment is based on the calculation of the size of the smallest microcalcification detectable on a radiograph, derived from the statistical decision theory. The mean glandular dose is simultaneously measured. Compared with conventional mammography units, the monochromaticity of synchrotron beams improves contrast and the use of a slit instead of an anti-scatter grid leads to a higher primary beam transmission. The relative contribution of these two effects on image quality and dose is discussed.