X-Ray Polarization Imaging
Final rept. 24 Jul 2002-23 Jun 2006
PENNSYLVANIA UNIV PHILADELPHIA
Pagination or Media Count:
Conventional mammography evaluates the spatial arrangement of tissue in the breast the recorded signal is determined by the x-ray attenuation of the materials in each projection. Due to the low x-ray energy, every x-ray attenuated by the breast is absorbed by the breast i.e., all of the x-ray energy is deposited in the breast. We have investigated whether it is possible to produce breast images based on x-ray polarization. Polarization radiography appeared to have the potential to supplement mammographic images by imaging the ability of breast tissue to rotate the x-ray polarization vector. We had hoped that new information about the breast could be gleaned at a low dose to the breast preference being given to x-rays which would pass through the breast and have altered polarization, rather than being absorbed by the breast. We performed fundamental experiments regarding x-ray polarization to determine whether the polarization effect was sufficiently large to allow it to be used to produce images. Two different x-ray polarimeters were developed and tested. We were able to demonstrate polarization of the incident x-ray beam. However, neither polarimeter allowed successful measurement of polarization alterations of any material. We did, however, develop an excellent model of x-ray spectra, which has already seen wide usage.
- Medicine and Medical Research