Latest developments in gamma-camera performance testing: resolution measurements

Resolution for gamma cameras has two distinct aspects: spatial resolution, referring to the ability to image closely spaced point or line sources of radioactivity as separate entities; and temporal resolution, referring to the ability to properly register two events occurring within a very small time interval as separate events. The BRH Test Pattern has been proven to be a valuable tool for the evaluation of spatial resolution in a wide variety of gamma cameras. A reading from a transmission image of this pattern provides adequate accuracy (0.5 mm minimal separation) for determining intrinsic resolution, and for making an evaluation of spatial distortion and nonuniformities. This pattern can be used for acceptance testing of newly installed equipment and for quality control of all types of gamma cameras as well. Images taken weely may reveal changes in intrinsic resolution, field uniformity, and spatial distortion that may occur gradually over a period of time