NEMA publishes revised PET standards
The National Electrical Manufacturers Association (NEMA) has published NEMA NU 2-2007 Performance Measurements of Positron Emission Tomographs, a revision that includes standards for PET, regardless of the scintillator used, and establishes methods of performance measurement on all currently available PET systems. The new standards are more accurate at measuring scatter fraction and random coincidences than previous versions.
The major change since the last edition addresses an improvement in the inclusion of cameras with intrinsically radioactive components. Affected tests include count losses and randoms, as well as sensitivity. The spatial resolution measurement has been expanded to include the measurement and reporting of source position. Appendix A has been deleted.
According to Michael E. Casey, PhD, a member of the Coincidence Imaging Task Force chartered by the Nuclear Standards and Regulatory Committee, NEMA NU 2-2007 specifies methods that can be performed on all currently available PETs. “These include single and multiple slice, discrete and continuous detector, and time-of-flight instruments, as well as multi-planar and volume reconstruction models, dedicated PETs, and other coincidence-capable imaging systems,” he said. “Wherever possible, future developments that could be readily anticipated were taken into account.”
The committee has not specified methods that may be particularly appropriate for evaluating time-of-flight instruments, pending further evaluation of those instruments by the clinical and scientific communities.