Continuing Education Series Quality Control in SPECT

Performance testing in single photon emission computed tomography (SPECT) imaging can occur at several times: acceptance (installation), routine (daily, weekly), and extended (monthly and at upgrades). Certain tests must become part of a regular effort to achieve the best possible results with a SPECT system. The final responsibility for optimal images lies with the nuclear medicine department rather than the vendor. The authors offer some suggestions for monitoring the imaging ability of SPECT camera-based systems. The main goals in performance testing are: (a) to ascertain minimum performance specifications as stated by the manufacturer; (b) to identify and correct losses of performance; and (c) to identify and correct the introduction of degradation with changes in hardware, software, and operators. Achieving and maintaining the best possible imaging results from a SPECT system can be obtained through the appropriate use of performance testing. Most procedures involved in performance testing are generic and independent of the computer and manufacturer. Many of these procedures may be performed by nuclear medicine technologists acquainted with the basic operating procedure for the system in question. One may incorporate these and other tests into a continuing schedule of quality assurance. Not every test described herein is possible with every system. Most of the procedures may be performed with a given system with little variation in the technique. The basic premise is that routine testing may pinpoint deficiencies ultimately resulting in improved patient studies. Artifacts from improperly operated systems and the basis for various compensations (flood, offset, etc.) have been well documented elsewhere (1-9).