Prior inverse filtering for the improvement of axial resolution.

A prior inverse filtering technique is applied to improve the axial resolution in ultrasonic imaging. The ultrasound transducer is excited by a synthesized signal corresponding to the impulse response of the inverse filter. The diffraction effects of the transducer and the observed scatterer, which limit the performance of the inverse filter, are examined experimentally as well as theoretically. Using a B-scan image of a tissue-equivalent phantom, we demonstrate the possibility of applying the prior inverse filtering method to improve medical ultrasound images.