Evaluation of contrast and recovery coefficients as performance parameters in planar and SPECT imaging

Abstract

The study focused on the performance evaluation of the gamma camera on the planar and SPECT imaging mode in nuclear medicine imaging. Several parameters were studied including the partial volume effect, contrast evaluation at different radiopharmaceutical size of localizations and the recovery coefficients. The localizations of Technetium-99m (99mTc) radionuclide were achieved by using Perspex® vials with different diameter sizes between 1.3 and 3.5 cm in a Jaszczak phantoms filled with water. The images were obtained in both planar and SPECT modes. The contrast in planar images showed no significant change when different activity of radionuclide was used. The contrast in SPECT images showed that the higher contrasts were achieved when higher time of projection used when lower activity of 99mTc were used. The contrast at higher 99mTc activity however was the highest when lower time of projection was used. The recovery coefficient in planar images showed a linear relationship to the size of radionuclide localizations and did not significantly affect the activity of the radionuclide. The recovery coefficient of SPECT images however were significantly affected by activity of the radionuclide. The recovery coefficient in SPECT increased dramatically when higher activity of the radionuclide was used. The overall results showed that the measurement of contrast and recovery coefficient can be used as performance parameters for both the planar and SPECT imaging in nuclear medicine.