A new PET detector concept for compact preclinical high-resolution hybrid MR-PET

The measured intrinsic spatial resolution (FWHM) was 0.74 +/- 0.01  mm in x- and 0.69 +/- 0.01  mm in the y-direction at the center of the detector. At the same point, the measured energy resolution (FWHM) was 13.01 +/- 0.05  %. The mean intrinsic spatial resolution (FWHM) over the whole detector was 0.80 +/- 0.28  mm in x- and 0.72 +/- 0.19  mm in y-direction. The energy resolution (FWHM) of the detector was between 13 and 17.3  % with an average energy resolution of 15.7 +/- 1.0  %. Due to the reduced thickness, the sensitivity of this gamma detector is low but still higher than pixelated designs with the same thickness due to the monolithic crystals. Combining compact design, high spatial resolution, and high sensitivity, the detector concept is particularly suitable for applications where the scanner bore size is limited and high resolution is required - as is the case in small animal hybrid MR-PET.