Mammographic phantom studies with synchrotron radiation

PURPOSE: To explore the potential improvement in image contrast for breast imaging with use of monoenergetic photons. MATERIALS AND METHODS: The x-ray energy available from the National Synchrotron Light Source is from 5 to over 50 keV. A specific energy is selected with a tunable crystal monochromator. The object is scanned with a narrow beam of 80.0 x 0.5 mm. Mammography phantoms were imaged with plate and film as the imaging detectors. Phantom images were obtained at 16-24 keV and compared with images obtained with a conventional mammographic unit. RESULTS: Preliminary findings indicate improved image contrast of the monoenergetic images compared with that obtained from the conventional x-ray source, particularly at 18 keV and below. CONCLUSION: Pilot results are encouraging, and the authors presently continue to explore monoenergetic photon imaging with improved instrumentation, scatter rejection, and use of tissue samples.