Quantitative assessment of induced errors in attenuation corrected myocardial SPECT images due to misregistration

Accurate attenuation correction can significantly improve the diagnostic accuracy of SPECT images. However, misregistration between the emission and attenuation maps can cause alignment induced artifacts in the attenuation corrected images. In this study we present a quantitative assessment of such errors in myocardial perfusion SPECT. A family of XCAT phantoms were imaged using the SIMIND Monte Carlo projector. To study the effects of misregistration, patient motion and respiratory motion were simulated. The differences between the test image and a reference image (perfectly aligned attenuation corrected image) were analyzed. The types of errors considered were lesion location errors, pixel density errors and change in contrast. Results indicate that horizontal translation causes the highest quantitative error and lesions in the lateral wall are most sensitive to misregistration induced errors.