Characterization of a Next-Generation Tissue-Equivalent Series Of Phantoms For Mammography

Date(s) - 07/02/2014
2:00 pm

James Allen, MS student

New tissue-equivalent phantom materials developed at the University of Florida have been used to update the breast tissue-equivalent series (BRTES) of phantoms originally designed there. This new iteration of BRTES, called BRTES-2, is manufactured to mimic both the attenuation and the density of the range of glandular and adipose tissue compositions encountered in mammography. Unlike BRTES, it is flexible and capable of being cut or reshaped following manufacture, allowing modifications to be made such as access channels for dosimetry. The BRTES-2 phantoms are capable of simulating breast tissues across the full range of glandularity (0% to 100%, or fully glandular to fully adipose) and can be manufactured in a variety of thicknesses to represent a compressed breast thickness at any glandularity to simulate any conceivable anatomical configuration. The fabrication techniques are presented, and the physical properties of the completed series of phantoms are described. The BRTES-2 phantoms were compared with simulated breast tissue using the Spektr computational toolset, modified to simulate mammographic x-ray spectra. The comparison shows that the half-value layer (HVL) of BRTES-2 and breast tissue agreed within 2% to 17% in the 20% to 70% glandularity range, with the closest agreement being found at 23 kVp.