A phantom and a procedure to obtain variable-object-contrast test images in gamma camera emission computed tomography (SPECT)

The value of test objects with a range of object contrast has been widely recognized for the testing of medical imaging equipment. A simple phantom is described, which, together with a data processing procedure, provides variable-contrast rod objects in gamma camera emission computed tomography (SPECT). There is only one compartment to fill with radioisotope, and data from hot rods, cold rods and a uniform section are available for analysis. The rod object contrast varies from 100% to 0%, with nine contrast steps used in this analysis. The measured image contrast in the transaxial slices is shown to be sensitive to variations in the system spatial resolution. With only one compartment to fill with radioisotope, this procedure is applicable for routine checking or optimization of gamma camera SPECT systems. (Author)