Title :
Quadratic equalization: a method for producing extended uniform depth of focus in high frame rate medical ultrasound B-scans
Author :
Zheng, Yibin ; Silverstein, Seth D.
Author_Institution :
Dept. of Electr. & Comput. Eng., Virginia Univ., Charlottesville, VA, USA
Abstract :
This work describes a new and novel method for achieving the beneficial imaging effects that can be obtained from the coherent superposition of multiple firings with a uniform distribution of transmit foci, with a single transmit firing. It is demonstrated that a sine amplitude modulation of the transmit windowing function with an argument quadratic in the transducer coordinates is essentially equivalent to a synthetic image generated from the coherent superposition of an infinite number of firings with their transmit foci uniformly covering the full range of an extended B-scan. Using these methods, simulation results give range compensated peaks of the range energy impulse response (measure of image brightness) that are flat within ∼ ±0.2 dB over the range scan of the B-mode image at fractional bandwidths commensurate with range resolutions down to ∼ 0.25 mm.
Keywords :
amplitude modulation; approximation theory; biomedical ultrasonics; brightness; equalisers; B-mode image; argument quadratic; extended uniform depth production; fractional bandwidths commensurate; high frame rate medical ultrasound B-scans; image brightness measurement; multiple firings coherent superposition; paraxial approximation; quadratic equalization; range energy impulse response; sine amplitude modulation; synthetic image; transducer coordinates; transmit foci uniform distribution; transmit windowing function; Amplitude modulation; Bandwidth; Biomedical imaging; Brightness; Energy measurement; Energy resolution; Focusing; Image generation; Transducers; Ultrasonic imaging;
Conference_Titel :
Signals, Systems and Computers, 2004. Conference Record of the Thirty-Eighth Asilomar Conference on
Print_ISBN :
0-7803-8622-1
DOI :
10.1109/ACSSC.2004.1399426