The PET-CT Phantom™ includes internal structures (three rods and six spheres) which, when imaged with both modalities, can demonstrate how accurately the two image sets are aligned. In addition, a single sample of radioactive water is attenuated by water, bone and CT contrast material (as well as air only) to determine how accurately the CT-based PET attenuation correction works. The Phantom is used for: Acceptance testing of PET/CT and SPECT/CT systems Routine quality evaluation of PET/CT and SPECT/CT systems Evaluation of new image fusion software Evaluation of new attenuation correction algorithms Aluminum tubes are for registration The outer 2" OD micro cylinder is for comparing attenuation region to non attenuation region The 6" ring is for contrast solution Research