Small animal PET scanners require high spatial resolution (< 1 mm) and good sensitivity. To obtain high resolution images, iterative reconstruction methods, like OSEM, applied to image reconstruction in three-dimensional (3D) positron emission tomography (PET)Small animal PET scanners require high spatial resolution (< 1 mm) and good sensitivity. To obtain high resolution images, iterative reconstruction methods, like OSEM, applied to image reconstruction in three-dimensional (3D) positron emission tomography (PET), have superior performance
over analytical reconstruction algorithms like FBP. However, the high computational cost of iterative methods remains a serious
drawback to their development and clinical routine use. The increase in performance of current computers should make iterative image reconstruction fast enough to attain clinical viability. However, dealing with the large number of probability
coefficients for the response of the system in high-resolution PET scanners becomes a difficult task that prevents the algorithms
from reaching peak performance. Taking into account all possible axial, in-plane and other symmetries, we have reduced the
storage needs what allows us to store the whole response of the system in dynamic memory of ordinary industry standard
computers, so that the reconstruction algorithm can achieve near peak performance.[+][-]
