Accounting for the hysteresis of respiratory motion of the heart in cardiac SPECT and PET using the Bouc-Wen model of hysteresis

Respiratory motion causes artifacts and blurring of cardiac structures in reconstructed slices in SPECT and PET studies. Respiratory motion correction methods based on amplitude binning of list-mode data have been observed to reduce but not eliminate the residual blurring when hysteresis of cardiac motion is present. The Bouc-Wen model of hysteresis is able to describe non-linear hysteretic systems and match the behavior of a hysteretic system to a range of hysteretic cycles. Our hypothesis is that the impact of hysteresis on the respiratory motion of heart can be accounted by developing hysteresis model employing modified Bouc-Wen equation. This study describes our investigation of our hypothesis through combined use of MRI and Visual Tracking System (VTS).