Investigation of gamma camera detector uniformity using a dynamic line phantom

Abstract

Background: Investigation of the applicability of the dynamic line phantom for determination o the uniformity of circular and rectangular field-of-view gamma cameras.
Methods: Count rate - activity and uniformity - count rate functions were determined by the dynamic line phantom on three circular field-of-view gamma cameras with 37 PMTs, on one circular field of view camera with 19 PMTs, and on one rectangular field-of view gamma camera with 59 PMTs, with and without a collimator. For an evaluation of the efficacy of the dynamic line phantom, the results were compared with the uniformity values obtained with a 99mTc point source and a 57-Co sheet source.
Results: In the optimum count rate range (20,000-30,000 cps for a circular field-of-view, 15,000-65,000 cps for a rectangular field-of-view) determined individually for each gamma camera, the uniformity values obtained with the dynamic line phantom did not differ statistically from the re fined with the 99mTc point source or the 57-Co sheet source.
Conclusions: The dynamic line phantom is suitable for the determination of detector uniformity, but the measurements should be performed within a well-defined activity (count rate) interval.