The philosophy and rationale of the standards measurements and illustrative examples of the analysis and results are presented in Journal of Nuclear Medicine@ vol. 43@ no. 10@ 2002. Daube-Witherspoon ME@ Karp JS@ Casey ME@ DiFilippo FP@ Hines H@ Muehllehner G@ Simcic V@ Stearns CW@ Adam L-E@ Kohlmyer S and Sossi V. ??PET Performance Measurements Using the NEMA NU 2-2001 Standard.?? pp. 1398-1409. With the exceptions of Section 8 for time-of-flight systems and Section 9 for hybrid PET/CT systems@ the Task Force has attempted to specify methods that can be performed on all positron emission tomographs. These include single and multiple slice@ discrete and continuous detector@ time-of-flight instruments@ multi-planar and volume reconstruction models@ and dedicated positron emission tomographs as well as other coincidence-capable imaging systems. Wherever possible@ future developments that could be readily anticipated were taken into account. While many PET tomographs are constructed as hybrid imaging systems such as PET/CT and PET/MR systems@ the standards committee has not specified special methods to assess hybrid imaging performance with the exception of the PET/CT registration test described in Section 9. It is expected that the PET component of a hybrid imaging system can be assessed using the methods described in this standard@ and other portions of the system can be assessed using other standards appropriate to that technology. The method for assessing the co-registration accuracy of hybrid PET/CT systems has the potential to be adapted to PET/MR systems. In the event a portion of any of the PET test methods described here cannot be executed in a hybrid imaging system@ workaround methods may be used@ but those methods must be described in the test report.