| Title |
Time-domain Estimation Algorithm for Ultrasonic Attenuation using Narrow-filtered Signals |
| Authors |
심재윤(Shim, Jaeyoon) ; 허돈(Hur, Don) ; 김형석(Kim, Hyungsuk) |
| DOI |
https://doi.org/10.5370/KIEE.2016.65.11.1887 |
| Keywords |
Ultrasound ; Attenuation ; Video signal analysis ; Bandpass filtering ; Diffraction compensation |
| Abstract |
The VSA(Video Signal Analysis) method is the time-domain approach for estimating ultrasonic attenuation which utilizes the envelop signals from backscattered rf signals. The echogenicity of backscattered ultrasonic signals, however, from deeper depths are distorted when the broadband transmit pulse is used and it degrades the estimation accuracy of attenuation coefficients. We propose the modified VSA method using adaptive bandpass filters according to the centroid shift of echo signals as a pulse propagates. The technique of dual-reference diffraction compensation is also proposed to minimize the estimation errors because the difference of attenuation properties between the reference and sample aggravates the estimation accuracy when the differences are accumulated in deeper depth. The proposed techniques minimize the distortion of relative echogenicity and maximize the signal-to-noise ratio at the given depth. Simulation results for numerical tissue-mimicking phantoms show that the Rectangular-shaped filter with the appropriate center frequency exhibits the best estimation performance and the technique of the dual-reference diffraction compensation dramatically improves accuracy for the region after the beam focus. |