Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method

Purpose An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with 99m Tc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. Methods The IBSC method corrects scatter on the reconstructed image I_AC ^μ b with Chang’s attenuation correction factor. The scatter component image is estimated by convolving I_AC ^μ b with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and 99m Tc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Results Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. Conclusion The IBSC method is a simple scatter correction technique feasible for use in clinical routine.