Three dimensional reconstruction of PET data from a multi-ring camera

In order to assess the potential of a multiring camera for three-dimensional PET (positron emission tomography) the septa were removed from a commercially produced PET camera (ECAT 931/08-12). An approximate reconfiguration was made to the data acquisition subsystem to acquire the full set of 64 sinograms containing all permitted lines of response between pairs of detectors. A number of different phantoms were imaged with this camera configuration, and one fluorodopa study was performed with a healthy volunteer. The authors discuss the results of these studies, and describe the back-projection and filtering procedure that has been adopted in order to incorporate the maximum amount of cross-plane data in the reconstruction. The results are compared with the same data reconstructed using the standard two-dimensional approach (i.e. for the direct and cross planes only), and with data collected for the same phantoms with the septa in place