Routine performance (constancy) testing of gamma cameras

Abstract

Objectives: The main objectives of the study consisted of the development and implementation of a routine performance (constancy) testing protocol for a gamma camera suitable for the use of radiographers and to identify any deterioration of the dual head gamma camera under study. Research Design: A constancy testing protocol based on IEC document TR 61948-2 and involving a set of performance indicators was developed. The performance indicators were measured over a period of time in order to investigate any possible deterioration in the performance of a gamma camera. The performance indicators studied were energy calibration stability, background, sensitivity, non-uniformity, integral uniformity, pixel size, spatial resolution and spatial linearity. Results: The results of this study were presented as a set of standard constancy testing charts. None of the performance indicators exceeded the maximum acceptable limits indicating that the camera is functioning as it should, however further investigations of sensitivity and pixel size is recommended. Conclusions: The protocol was found to be suitable for the particular gamma camera unit under study. Suggestions for further improvement of the protocol and for improvement of the QC procedures at the hospital concerned were put forward.