New concurrent acquisition and reconstruction (CAR) system for PET study

PET has been advanced more than 30 years and finally, high spatial resolution PET having FWHM resolution of 2.5 mm, such as HRRT, has been developed. However, excessive reconstruction time still left as a major problem. This can be more serious at HRRT system which processes huge amount of data acquired from more than 120,000 detectors. For example, it takes about 80 minutes to reconstruct a single frame image at the HRRT system even with the eight-node cluster reconstruction system provided by Siemens. Due to this very long reconstruction time, it has been impossible in the PET studies to conduct real-time reconstruction or concurrent reconstruction while scanning. We developed a new concurrent acquisition and reconstruction (CAR) system by extending the FBPR system and the SSP algorithm. With the CAR system, the operator can immediately check the scanning status by observing the fully reconstructed image of each frame while scanning. So, the operator can interactively control the intensity at a specific ROI by checking the reconstructed image and managing dose activity while PET scan. The CAR system firstly makes the real-time reconstruction possible and provides numerous new opportunities to the neuroscience studies. In fact, we combined the CAR system and HRRT and conducted real time reconstruction for 32 frames dynamic study. In addition, the new system can be used as the high-speed reconstruction system for the dynamic PET scan reconstruction. When the scan is finished, the CAR system provides all the frame images within the time required only for a final single frame reconstruction.