Real-Time Data Rebinning in PET to Obtain Uniformly Sampled Projections

In many PET systems, the detector arrays can move during data acquisition in order to augment the sampling rate. This increases resolution and eliminates aliasing noise. With discrete detector movement there is a fairly long minimum scan duration. Continuous precession (wobble) allows shorter scans but increases in on-line memory needed. We modified the Positome III at the Montreal Neurological Institute to allow it to precess continuously, and interpolate the coincidence data in real time into uniformly sampled parallel projections. We are now able to perform 12 mm resolution scans of any frame rate greater than 2 seconds using 30% of the memory previously needed. Furthermore, we have reduced the reconstruction time by one third.