Fig. 3

PET spatial resolution in the presence of the MRI instrument. a A schematic of the Derenzo phantom (image reproduced with permission from Phantech Medical). b MR image of the phantom. c The phantom with ~ 3.7 MBq (100 µCi) of fluorine-18 was placed at axial center in the PET insert. A spatial resolution of 1.0 mm was achievable. d The phantom of fluorine-18 and the PET insert were moved inside the MRI instrument. A spatial resolution of 1.0 mm was still achievable along with sharpening of the channels in some sections (yellow arrows). e The phantom with ~ 3.7 MBq (100 µCi) of gallium-68 was placed at axial center in the PET insert. The spatial resolution was greater than 1.5 mm. f The phantom with gallium-68 and the PET insert were moved inside the MRI instrument, and a spatial resolution of 1.2 mm was achievable