Calculation of Tei index and LV motion amplitude based on cardiac physical phase

Cardiac physical phase (CPP) is another method for phase partition of cardiac motion besides the conventional cardiac time phase (CTP). The partition basis of CPP is not time but the deform information of left ventricle (LV) in different stages. The length of each CPP can reflect the function of LV, and CPP is also the calculation base of many other function parameters. So far the partition of CPP is all by empirical estimation or indirect method. This paper proposes a direct method for CPP accurate partition according to LV shape factor including LV volume (LVV) and length of LV long-axis (LVLL). Further more a new parameter named LV wall motion amplitude (LVMA) is defined to analyze the LV wall movement in different CPPs. Two LV function indexes Tei and LVMA are calculated with the result of CPP division. The validity of this method is demonstrated by an experiment with real human LV data.