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Statistical variability of the PET data pre-corrected for random coincidences or acquired in sufficiently high count rates can be approximated by a Gaussian distribution, which results in a penalized weighted least-squares (PWLS) cost function. In this study, a proximal preconditioned gradient algorithm accelerated with ordered subsets (PPG-OS) is proposed for the optimization of the PWLS function,...
Parametric estimation of perfusion using [15O]-H2O is an important biomarker for assessing treatment response in oncology clinical trials involving anti-vascular and anti-angiogenic agents. Traditionally the set of dynamic images are reconstructed independently, followed by post-reconstruction kinetic modelling. This methodology results in sub-optimal and often noisy end point parameters if voxel-by-voxel...
Incorporation of the resolution modelling component of the scanner during statistical image reconstruction often produces images of improved signal-to-noise ratio (SNR). In our previous work we measured and parameterized the Hi-Rez PET/CT scanner's point spread function (PSF) in image space using printed point source arrays at multiple positions. Here we extend the work to the TruePoint PET/CT and...
Direct application of the expectation maximisation (EM) algorithm to the spatiotemporal maximum likelihood problem results in a convenient separation of the image based problem from the projection based problem. This enables any spatiotemporal 4D image model to be incorporated into MLEM image reconstruction with relative ease, only requiring tailored calculation of the fitting weights. As a preliminary...
A new practical and computationally efficient method for deriving and applying the space-variant blurring component of the system matrix is proposed and applied to the HiRez PET/CT scanner. The point spread function (PSF) was sampled at 14400 locations within the field-of-view (FOV) using an array of 120 18-F printed point sources. An HP printer was modified to print the sources on a sheet of A4 paper...
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