Purpose: The quality control of the gamma camera is obligatory for the proper diagnosis of the patients. The most intensive and sensitive routine quality control of gamma camera is intrinsic uniformity. The main objective of this research work is to determine the best parameters for daily quality control testing of intrinsic uniformity for dual head Single Photon Emission Computed Tomography (SPECT) gamma camera.
Method: The integral and differential intrinsic uniformity test for both Useful Field Of View (UFOV) and Central Field Of View (CFOV) was done by placing a point source of 99mTc in front of the detectors with removed collimators to measure the effect of source activity and source volume on intrinsic uniformity.
Result:The result shows that the best intrinsic uniformity image is obtained at activity volume in the range of 0.2 – 0.7 ml in 3 ml syringe with source activity between 70 – 200 MBq since place of point source on the central axis of the detector at a distance from its face equal to five times the diameter of the useful field of view as defined by the lead mask.
Conclusion: Finally we can conclude that, the lower the intrinsic uniformity the better the imaging and diagnosis.
|