Analysis of Gamma Camera Detector Stability and Its Effect on Uniformity Correction For SPECT

A critical analysis of regional changes of detector uniformity over time on uniformity correction and its effect on single photon emission computed tomography (SPECT) imaging was performed. Three tomographic imaging systems were tested using a sequential imaging technique and computer analysis of the change of regional uniformity in all images. Our study revealed a direct correlation between the accuracy of uniformity correction and the introduction of uniformity related artifacts after image reconstruction. Each gamma camera detector demonstrated a unique period of stability for accurate uniformity correction and artifact-free reconstructed images. Periods of acceptable uniformity stability ranged from 6 hr to 10 days.