Simulation and patient studies of scatter correction in cardiac SPECT imaging

Introduction: Myocardial perfusion imaging is a nuclear medicine imaging method that is used to detect coronary artery diseases. One of the main sources of error in this imaging method is the detection of Compton scattered photons in the photopeak energy window used for data acquisition. This results in the degradation of the image contrast, and therefore decreases the diagnostic accuracy. Material and Methods: In this study, the efficiency of dual-energy window (DEW) correction method regarding the reduction of the undesirable influence of scattering was investigated using the images acquired from the 3D-NCAT simulated phantom, and a group of patients (18 males and 27 females) in both rest and stressful situations. To evaluate the scatter correction method, the image contrasts are calculated before and after applying the scatter correction. Results: The results obtained from this study indicated that the calculated image contrasts enhanced by applying the scatter correction in both simulation and patient studies. In the simulation study, the relative values of increase in image contrast are about 10.15% and 12.58% when using a k value equal to 0.5, and the linear fitting method, respectively. In the patient study, the relative values of increase in image contrasts regarding the rest and stress situations were about 13.63% and 10.84% for females and 12.03% and 10.56% for males, respectively. Conclusion: The utilization of the DEW method for scatter correction of cardiac SPECT images results in an increase in the image contrast and the improvement of the image quality.