Scintillation Camera Field Uniformity: Visual or Quantitative?

Global and local scintillation camera uniformity were studied phenomenolgically with emphasis on statistical features. A system parameter (the systematic error) was developed to quantitate global field uniformity. (The systematic error also appears to predict the maximum variation in response resulting from local irradiation of the detector.) Uniformity correction by a statistically weighted matrix renormalization procedure was demonstrated to improve the global frequency distribution of the counts per pixel. Such a renormalization procedure also slightly improved local response if the systematic error was small but not if the systematic error was large. The failure of this renormalization procedure appeared to correlate with long range interactions in the detector. The existence of such long range interactions casts doubt on the efficacy (and even the desirability) of many commonly used uniformity corrections.