Preliminary evaluation of image quality in a new clinical ToF-PET/MR scanner.

GE Healthcare, Waukesha, USA A new ToF-PET/MR scanner has recently been deployed at the University Hospital of Zurich for clinical evaluation purposes. The goal of the present work was to compare the image quality obtained on this system with that of equivalent state-of-the-art standalone scanners. The GE Signa PET/MR is a whole-body scanner combining a 3T wide-bore MR system with a 25 cm PET detector ring based on SiPM technology and mounted on a customized radiofrequency coil. MR image quality of this system was tested by scanning two volunteers: One with a brain protocol and another with a whole-body protocol. The same scans were repeated before and after PET detectors were installed on the system. A baseline measurement was acquired on a Discovery 750w scanner with the same volunteers. PET image quality was tested on patients referred for an FDG PET/CT scan. After 15-20 minutes of PET/CT, the patients were moved to the PET/MR, where an equivalent acquisition was performed. Data were reviewed by nuclear medicine and radiology physicians. As seen in Figure 1, MR image quality in the brain is identical between PET/MR (preand post-insert) and