Development of Prototype Quality Control Phantom for Gamma Camera and SPECT System

Abstract

This study was designed to experiment the result of the indigenous phantom with associated algorism and compares the result to the standard one. The phantom was designed according to the parameters recommended by NEMA, IAEA and some other researcher. A low cost material were used to simulate the 4-quadrate bar phantom, Slit phantom and Liquid flood phantom in order to achieve the gamma camera resolution, linearity and uniformity. A Perspex materials was used to fabricate the flood phantom and Perspex with a lead materials and silicon were used to simulate the bar phantom while a pure lead was used to fabricate the Slit phantom. IDL was used to develop a mathematical algorism in order to analysis the result of indigenous phantom. The devolved phantom was experimented at Royal Care Hospital RCH and Radiation and Isotopes Center of Khartoum RICK. 1.3mCi of 99m Tc and 1500ml water were used to prepare the flood phantom and then is centered at camera table with four quadrant bar phantom or Slit phantom perpendicular to it and image were acquired with optimum matrix size. Then the images were assessed using our developed IDL algorism to measure the resolution, linearity and uniformity of those cameras. The results of the fabricated phantom showed that the resolution of two cameras increase as the objects size increased and the camera resolution decreased as the object frequencies increased with averaged resolution of 94% and 89.5% with comparison to standard NEMA phantom which represent resolution of 95.5% and 90.8% for RCH and RCIH respectively. The spatial linearity is calculated and was 0631mm and 0.639mm for X and Y axis respectively for UFOV and the slandered phantom appear an absolute linearity of 0.70mm for both axis. The uniformity of the two cameras showed a 3.18% and 2.27% for I.U and D.U respectively for UFOV and the standard phantom shows uniformity of 2.0% and 1.5% for I.U and D.U for UFOV respectively. The developed phantom could be used with acceptable accuracy in the field of nuclear medicine to curry out the quality control tests of gamma camera SPECT, which is consider as general multi functional phantom as it could measures the resolution, linearity and flood field uniformity independency on type or manufactures of camera.