Preliminary results from the AROPET

AROPET (Animal ROtational PET)-a rotational PET with four detectors based on BGO crystals coupled to position sensitive photomultiplier tubes has been constructed. The effective field-of-view is 50.4 mm (transaxial) by 44.8 mm (axial), which is suitable for imaging small animals. In this system, animals can be imaged with two imaging modes, planar imaging and tomographic imaging. With the planar imaging mode, the AROPET works like a gamma camera, and a 2D planar projection image is obtained. With the tomographic imaging mode, the detectors are rotated through 90°, and 3D tomographic images are obtained. The rotating diameter of AROPET is flexible and can be adjusted between 220 mm∼380 mm. The spatial resolution at the center is 2.73 mm (FWHM) while the diameter is 220 mm. The energy resolution and counting rate performance have been measured. Initial results of phantoms and animal studies obtained from AROPET are presented also.