Design and System Evaluation of a Dual-Panel Portable PET (DP-PET)

Abstract

Background: Integrated whole-body PET/MR technology continues to mature and is now extensively used in clinical setting. However, due to the special design architecture, integrated whole-body PET/MR comes with a few inherent limitations. Firstly, whole-body PET/MR lacks sensitivity and resolution for focused organs. Secondly, boarder clinical access of integrated PET/MR has been significantly restricted due to its prohibitively high cost. The MR-compatible PET insert is a low cost and flexible PET scanner which can be placed within an MRI bore. However, mobility and configurability of all existing MR-compatible PET insert prototypes remain limited. Methods: An MR-compatible portable PET insert prototype, Dual-panel Portable PET (DP-PET), has been developed for simultaneous PET/MR imaging. Using SiPM, digital readout electronics, novel carbon fiber shielding, phase-change cooling and MRI compatible battery power, DP-PET was designed to achieve high-sensitivity and high-resolution with compatibility with a clinical 3T MRI scanner. A GPU-based reconstruction method with Resolution Modelling (RM) has been developed for the DP-PET reconstruction. We evaluated the system performance on PET resolution, sensitivity, image quality and the PET/MR interference. Results: Initial results reveal that the DP-PET prototype worked as expected in the MRI bore and caused minimal compromise to the MRI image quality. The PET performance was measured to show a spatial resolution <= 2mm (parallel to the detector panels), maximum sensitivity =3.6% at the center of FOV and energy resolution = 12.43%. MRI pulsing introduces less than 1% variation to the PET performance measurement results. Conclusions: We developed a MR-compatible PET insert prototype and performed several studies to begin to characterize the performance of the proposed DP-PET.The results showed that the proposed DP-PET performed well in the MRI bore and would cause little influence on the MRI images. The Derenzo phantom test showed that the proposed reconstruction method could obtained high quality images using DP-PET.