Feasibility study of entire whole-body PET scanners based on the OpenPET geometry

A conventional PET scanner has a 15-25 cm axial field-of-view (FOV) and images a whole body using about six bed positions. An OpenPET geometry can extend the axial FOV with a limited number of detectors. The entire whole-body PET scanner must be able to process a huge amount of data, effectively. In this work, we study feasibility of the full 3D entire whole-body PET scanner using the GATE simulation. The OpenPET has 12 block detector rings with the ring diameter of 840 mm and each block detector ring consists of 48 DOI (depth-of-interaction) detectors. Total axial length is 955 mm. Open gap setting of 318 mm provides the continuous axial FOV. The OpenPET has higher loss of single data than a conventional PET scanner at grouping circuits. NECR of the OpenPET decreases by loss of single data. But, loss of single data is improved by separating the axially arranged detector into two parts. Also, multiple coincidences are found to be important for the entire whole-body PET scanner. The entire whole-body PET scanner with the OpenPET geometry promises to provide a large axial FOV with the open space and to have sufficient performance values.