MRI investigation of the linkage between respiratory motion of the heart and markers on patient's abdomen and chest: Implications for respiratory amplitude binning list-mode PET and SPECT studies

Amplitude binning has become the standard for binning list-mode acquisitions for correction of respiratory motion in PET and SPECT. However, the question of how to detect the presence of and correct for possible hysteresis between the signals obtained from surface movement of the patient's body (whose amplitude is used in binning) and the motion of the heart within the chest remains open. Our hypothesis is that the addition of information from movement of the patient's chest to that obtained from the abdomen may provide the necessary information to detect and allow correction of hysteresis. This study reports our investigation of this hypothesis through combined MRI tracking of the internal motion of the heart and other internal structures with measurement of body surface motion via a bellows about the abdomen and stereo-tracking of markers on the volunteer's chest and abdomen by a visual-tracking system (VTS).