Improved Tracking Performance In High Frame Rate Imaging Using Iterative Phase Tracking

High frame rate ultrasound imaging is necessary to enable tracking of rapid dynamic events such as the carotid pulse wave velocity. Several studies have shown that it is feasible to use motion tracking methods that are applied on standard ultrasound frame rates also on very high frame rates. However, few studies have addressed the issue of accumulated tracking errors over vast numbers of frames during Lagrangian tracking. These could stem from e.g. limited signal-to-noise ratio often resulting from the use of plane wave imaging. One recently proposed solution was to combine motion tracking with an iterative tracking scheme. The purpose of this study has been to evaluate if the iterative tracking scheme could be exploited to increase the robustness of a phase-based tracking method in high frame rate plane wave imaging to track the carotid artery wall diameter. The results showed the iterative tracking scheme to give increased robustness with significantly (p<0.0003) less differences in measured lumen diameters between adjacent lines. Thus, this study enforces the suggestion to use the iterative tracking scheme during Lagrangian tracking in high frame rate imaging.