Initial Evaluation of a TOF, Open-ring PET Scanner with Continuous Variable Diameter

We propose a TOF, open-ring PET scanner with continuously variable diameter for in-situ imaging. The detectors of the scanner could be spread or shrunk along circumference direction, provides an adaptive FOV for bodies of different sizes. The annular shape contributes to higher sensitivity and better response homogeneity than the panel scanner composed with the same detector number and internal diameter. The simulation results show the image quality and the response homogeneity of the open-ring scanners get worse than those of the full-ring scanner (with coincidence time resolution of 380 ps), but the fluctuation of the background variance (improved 4.5%~6.1%) and the hot lesion contrast (reduced 3.9%~11.8%) is acceptable even the open angle reaches up to 180°.