RT Journal Article
SR Electronic
T1 Performance of a PET Insert for High Resolution Small Animal PET/MR Imaging at 7T
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP jnumed.116.187666
DO 10.2967/jnumed.116.187666
A1 Stortz, Greg
A1 Thiessen, Jonathan D
A1 Bishop, Daryl
A1 Khan, Muhammad S
A1 Kozlowski, Piotr
A1 Retière, Fabrice
A1 Schellenberg, Graham
A1 Shams, Ehsan
A1 Zhang, Xuezhu
A1 Thompson, Christopher J
A1 Goertzen, Andrew
A1 Sossi, Vesna
YR 2017
UL http://jnm.snmjournals.org/content/early/2017/09/14/jnumed.116.187666.abstract
AB We present the characterization of a compact magnetic resonance (MR) compatible positron emission tomography (PET) insert for simultaneous pre-clinical PET/MR imaging. While specifically designed with the strict size constraint to fit inside the 114 mm inner diameter of the BGA-12S gradient coil used in the Bruker 70/20 and 94/20 series of small animal MR imaging (MRI) systems, the insert can be easily installed in any appropriate MRI scanner or used as a stand-alone PET system. Methods: The insert is made from a ring of 16 detector-blocks each made from depth-of-interaction capable dual-layer-offset arrays of cerium-doped lutetium-yttrium oxyorthosilicate crystals read out by silicon photomultiplier (SiPM) arrays. Scintillator crystal arrays are made from 22×10 / 21×9 crystals in the bottom/top layers with 6/4 mm layer thicknesses, arranged with a 1.27 mm pitch, resulting in a useable field of view (FOV) 28 mm long and ~55 mm wide. Results: Spatial resolution ranges from 1.17 to 1.86 mm full-width-at-half-maximum (FWHM) in the radial direction from a radial offset of 0 to 15 mm. With a 300-800 keV energy window, peak sensitivity is 2.2% and noise-equivalent count rate (NECR) from a mouse-sized phantom at 3.7 MBq is 11.1 kcps and peaks at 20.8 kcps at 14.5 MBq. Phantom imaging shows that feature sizes as low as 0.7 mm can be resolved. 18F-fluorodeoxyglucose (18F-FDG) PET/MR images of mouse and rat brains show no signs of inter-modality interference, and can excellently resolve substructures within the brains. Conclusion: Due to excellent spatial resolvability and lack of intermodality interference, this PET insert will serve as a useful tool for pre-clinical PET/MR.