Adaptive thresholding incorporating temporal and spatial information with eigen-based clutter filter for color Doppler processing in ultrasonic systems

Color Doppler imaging is mainly used to observe the blood flow in the region of interest. The desired blood signal will be greatly affected by the clutter noises, and conventional linear clutter filter may not eliminate clutter noises effectively without the assistance of the thresholding mechanism. In this work, we proposed an adaptive thresholding mechanism with probability-based clutter power ratio (PCPR) incorporating temporal and spatial information based on the maximum-likelihood (ML) and maximum a posteriori (MAP) criteria. The proposed mechanism can verify the blood and tissue regions more accurately and eliminate all the undesired clutter noises in the verified tissue regions. The proposed mechanism has 5-10 dB better performance than the referenced algorithms due to its nonlinear property.