Single Photon Planar Imaging

Abstract

Quality assurance measurements on y cameras are complicated; and variations among institutions have highlighted the need for a standard implementation (Marshall and Wells 1999). The measurements have to satisfy two vital demands. The first is to provide a pre-purchase comparison of the performance of different cameras and, in post-purchase acceptance tests, to determine whether the user specifications have been achieved. The second is to assess the acceptability of a particular camera, for clinical imaging, over the duration of its use; and to detect any deterioration in performance early enough to allow preventive servicing, before failure, in order to reduce clinical down-time and the possibility of interrupted patient investigations. Many comprehensive recommendations have been published, which can be categorised into manufacturer oriented and user oriented. The manufacturer oriented tests developed by the National Electrical Manufacturers’ Association, NEMA (Hines et al. 1999a,b, 2000; NE-MA 1994, 2001), are usually intrinsic and undertaken in air whereas those developed by the International Electrotechnical Commission, IEC (IEC 1992, 1998), are undertaken in the presence of scatter and therefore more closely simulate the clinical performance of the camera. The user oriented tests are described in: AAPM (1982, 1987); IAEA (1991); IPSM (1992); Ficken and McCartney (1994); Waddington et al. (1995); IPEM (2003). At acceptance, data should be compared with the manufacturer’s factory or installation data and at routine testing, they should be compared with reference or previous data (IAEA 1991).