Compensation method for frequency-dependent attenuation in tissue imaging by amplitude modulation for chirp transmission

Ultrasound imaging of deep parts in a living body with high resolution and high signal-tonoise ratio is strongly required. The pulse compression technique is efficient for achieving a high signal-to-noise ratio, and wide-band imaging is important for realizing high image resolution. Hence, a wide-band transducer is intensively studied. However, high-frequency components in a wide-band transmission tend to be affected by frequency-dependent attenuation. This decreases not only the signal-to-noise ratio but also the image resolution, since the distortion of echo signals makes exact pulse compression impossible, i.e., the pulse width of the compressed echo signal becomes broad. In this study, we examine the compensation of frequency-dependent attenuation in pulse compression imaging using FM chirp signals.