Impact of Using Uniform Attenuation Coefficients for Heterogeneously Dense Breasts in a Dedicated Breast PET/X-ray Scanner.

We investigated PET image quantification when using a uniform attenuation coefficient () for attenuation correction (AC) of anthropomorphic density phantoms derived from high-resolution breast CT scans. A breast PET system was modeled with perfect data corrections except for AC. Using uniform for AC resulted in quantitative errors roughly proportional to the difference between used in AC ( ) and local , yielding approximately ± 5% bias, corresponding to the variation of for 511 keV photons in breast tissue.

Simulation study of quantitative precision of the PET/X dedicated breast PET scanner.

The goal for positron emission tomography (PET)/X is measuring changes in radiotracer uptake for early assessment of response to breast cancer therapy. Upper bounds for detecting such changes were investigated using simulation and two image reconstruction algorithms customized to the PET/X rectangular geometry. Analytical reconstruction was used to study spatial resolution, comparing results with the distance of the closest approach (DCA) resolution surrogate that is independent of the reconstruction method.