Automatic Time Gain Compensation in Ultrasound Imaging System
Many automatic time gain compensations are proposed, but most of them depart from the assumption that ultrasound signals are homogenous attenuated across examined tissues, which is often violated. In real ultrasound system, the large attenuation variation between different types of tissues confused the attenuation compensation. In this paper, considering the frequency shift effect, we propose the quadratic least square fitting to estimate the attenuation profile. Further, as for the large attenuation variations in image, especially around the anechoic regions, we proposed a new algorithm by adding two power functions to control the gain range and reduce the affluence of overwhelming gain value caused by noise and edges around anechoic regions. Test results of phantoms and ultrasound images show the new algorithm could effectively adapt to the large attenuation variation and provide a desired uniform image.