Block-iterative image reconstruction methods, such as ordered subset expectation maximization (OSEM), are commonly used to accelerate image reconstruction. In OSEM, the speed-up factor over maximum likelihood expectation maximization (MLEM) is approximately equal to the number of subsets in which the projection data are divided. Traditionally, each subset… (More)
PURPOSE Small-animal single photon emission computed tomography (SPECT) with focused multi-pinhole collimation geometries allows scanning modes in which large amounts of photons can be collected from specific volumes of interest. Here we present new tools that improve targeted imaging of specific organs and tumours, and validate the effects of improved… (More)
We demonstrate new technologies for SPECT imaging with unsurpassed resolution in mice and rats. Results of the imaging of living animals will be shown. In addition development of detectors for next generation systems with an even higher resolution will be shown.