Signal to Noise Ratio Improvement of Ultrasound Harmonic Images Using Coded Excitation and Adaptive Line Enhancer

Signal to Noise Ratio (SNR), is one of the parameters that has significant effect on quality of ultrasound images, especially harmonic images. In ultrasound images the frequency dependent attenuation can reduce the SNR of images that are reconstructed with higher harmonics. In this paper, to improve the SNR of harmonic images, frequency modulated signals (chirp), along with the adaptive line enhancer (ALE) is proposed. The ALE is applied on compressed receive signal after matched filtering (MF). The results show more than 3dB improvement in SNR value and around 5mm improvement in penetration depth of harmonic signals that are separated by pulse inversion method.