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PET scanner accreditation is based on reviews of images acquired from the ACR PET phantom. The phantom is relatively easy to fill and set up for a PET study and can be used to measure tomographic uniformity, spatial resolution, and the detectability of “hot” lesions. The variety of resolution and “hot” components enables the reviewers to see relatively subtle differences in system performance. The accreditation phantom images are submitted to a review panel of qualified medical physicists for scoring. The Nuclear Medicine Accreditation Committee has defined acceptable standards for uniformity, spatial resolution and lesion detection. Uniformity and noise are evaluated qualitatively by inspection of reconstructed tomographic sections. Optimal density ranges should be comparable to those used for clinical images.Spatial resolution is judged by identifying the smallest “cold” rods in the phantom and lesion detectability is determined from the “hot” cylinders. The same protocol is also used for the “cold” cylinders that demonstrate the effectiveness of the attenuation and scatter corrections. Learning Objectives: 1. Be aware of the ACR PET accreditation process and PETPhysicist Qualifications. 2. Understand the ACR PET Phantom and testing required for ACR accreditation. 3. Understand how phantom images are reviewed by the ACR. 4. Be able to activate the ACR Phantom. 5. Understand phantom image acquisition and processing. 6. Understand PET phantom imagecontrast, resolution, and uniformity.

The objectives of this workshop are to provide an overview of the different commercially available PET/CT scanners and to gain the necessary knowledge of PET/CT QC/QA procedures as well as the criteria needed for PET scanner accreditation and acceptance testing. The first objective will be met during the first day whereby three presentations will be provided covering the PET/CT scanner offerings from GE Health Care, Siemens Medical Solutions, and Philips Medical Systems respectively. The presentations will focus on PET scanner design, performance, and capabilities and will be given by respective users of the equipment rather than representatives of the manufacturers. The second objective will be met during the second day of the workshop, whereby four speakers will discuss topics on PET/CT QC/QA procedures, PET NEMA acceptance testing,PET ACR accreditation, and PET site shielding calculations and requirements.

The front collimator surface of a conventional single‐photon emission computed tomography(SPECT) detector system transcribing an elliptical orbit to approximate body contour could, under certain circumstances, penetrate the ellipse and make patient contact. The problem is associated both with the large front surface dimensions of tomographic cameras and the need to maintain the camera perpendicular to a radius through the axis of rotation. To aid in the development of an improved body contour orbit, software has been developed to simulate SPECTimagingsystems. A major feature of the algorithms is a spatially calibrated graphic representation of the pallet, patient and orbit of the camera head. Based on computer simulations performed with this software, a modified elliptical orbit has been proposed for patient contour SPECT scanning on two different types of tomographic acquisition systems: a dual camera, rotating ring system and a single camera, multimotion stand system. This peanut orbit has the advantage of minimizing collimator patient distance, as does the elliptical orbit, but also compensates for camera motion that could potentially produce patient contact. Versions of the peanut orbit algorithms have been installed and are operational on clinical systems similar to those that were simulated. The ring‐based gantry system (with cameras mounted on cantilevered arms) requires additional software to correct for translational shift in the field of view as a function of radial distance from the center of the system. This is done during uniformity correction. Standard unmodified backprojection software is used for reconstruction. The peanut orbit may represent an improved approach to body contour imaging in rotational SPECT.