Influence of Speed Motion in Dedicated Open Geometry PET System

An open geometry dedicated PET scanner that allows patient motion is proposed. This PET configuration poses several challenges to image reconstruction, such as angular limitation, the presence of motion in the acquisition and the sensitivity correction problem. To correct the motion artifacts, a frame-based motion correction in three phases that uses an external tracking system is proposed. An experimental study of a moving source with different speeds has been carried out to study the influence of the speed on the degradation of the image corrected by our algorithm. The method can divide the acquired data from the scanner in frames, considering the size of the object of study. This approach allows working with low statistical information without losing image quality. The frames are later registered using spatio-temporal registration developed in a multi-level way. To validate these results, three performance tests are applied showing excellent values of similarity (in the range of 90-95%) with the ground-truth (static) image, and high signal-noise ratios (around 60 decibels). It also finds a small degradation of the image (0.01 error) when the speed of the source motion is higher than the spatial precision of the tracking system.