Spatial response, which directly decides the resolving power of the system is greatly affected by the parameters like source- collimator detector geometry, beam profile, sampling space and angular distribution of projections. Also image contrast is directly affected by factors like energy window selection, scattering contribution etc.

The changes in above parameters to improve one may affect the other requiring optimal selection of these parameters.

A tomographic CT scanner comprising of 10 Ci Cesium-137 source and a single NaI(Tl) detector with computer controlled single axis manipulator and data acquisition and processing system has been utilised for this optimisation exercise.

The paper discusses the methodologies and results of these optimisation experiments and stresses the need for regular checks to detect any variation in these parameters.