Partial volume correction of PET image data using geometric transfer matrices based on uniform B-splines.


Most methods for partial volume correction (PVC) of positron emission tomography (PET) data employ anatomical segmentation of images into regions of interest, an approach that is not optimal for exploratory functional imaging beyond regional hypotheses. We describe a novel method for unbiased voxel-wise PVC.
Approach:
B-spline basis functions were combined with geometric transfer matrices to enable a method (bsGTM) that provides PVC or alternatively provides smoothing with minimal regional crosstalk. The efficacy of the new method was evaluated using simulations, human PET data, and murine functional PET data.
Main Results:
In simulations, bsGTM provided recovery of partial volume signal loss comparable to iterative deconvolution, while demonstrating superior resilience to noise. In a real murine PET dataset, bsGTM yielded much higher sensitivity for detecting amphetamine-induced reduction of [11C]raclopride binding potential. In human PET data, smoothing using bsGTM enabled increased signal to noise ratios with less degradation of binding potentials relative to smoothing by Gaussian convolution or non-local means.\
Significance:
bsGTM offers improved performance for PVC relative to iterative deconvoltion, the current method of choice for voxel-wise PVC, especially in the common PET regime of low signal to noise ratio. The new method provides an anatomically unbiased way to compensate partial volume errors in cases where anatomical segmentation is unavailable or of questionable relevance or accuracy.&#xD.