Abstract
In FDG PET imaging, FDG uptake in tumors less than 2 cm in diameter is inherently underestimated due to the partial-volume effect (PVE) because PET images have limited spatial resolution. With regard to the deconvolution method, we use the Richardson-Lucy (RL) algorithm with total valuation (TV) regularization. In the first step of our PVE correction method, PET images are expanded with B-spline interpolation. In the next step, the RL algorithm with TV regularization is executed for an expanded image. In addition, the point spread function is assumed to be 3-D Gaussian. In the present study, our PVE correction method was evaluated using 12 spherical phantoms ranging from 6 to 40 mm in diameter. The results showed that our method reduced the inaccuracy due to the PVE in phantoms more than 8 mm in diameter and that the use of the RL algorithm with TV regularization provided values very close to the true SUV values for FDG uptake. Clinically, our method demonstrated an increase in the observed FDG uptake in a small brain tumor, resulting in improved contrast relative to the background.
