Ultrasonic Attenuation Imaging Using Coherent Processing In Ultrasonic Computer Tomography

Ultrasonic Attenuation Imaging Using Coherent Processing In Ultrasonic Computer Tomography

Paper in proceedings (conference paper)

This paper presents an improving modification to a recently published ultrasonic attenuation imaging method [1]. In this method, the attenuation coefficients are estimated in a volume, where directly transmitted, reflected, and scattered ultrasonic waves can be recorded - an ultrasonic computer tomography system. All of the recorded signals are used for the attenuation estimation. More information is used for the image reconstruction than in other known approaches; thus the distribution of local attenuation can be reconstructed more accurately. However, this approach has a theoretical limit. It introduces a simplified model of the imaged volume, where only a small number of scatterers / reflectors are assumed. When responses from multiple reflectors / scatterers combine at the receiving transducer, the estimation based on such signal is not correct. In real tissue, obviously, this simplifying assumption can not be guaranteed. The, modifying idea consists in incorporating coherent preprocessing of the recorded signals in a small neighborhood (subarray) of the receiving transducers. By using phased subarray signal processing, the responses from individual reflectors / scatterers can be distinguished, thus overcoming the limitation.

This paper presents an improving modification to a recently published ultrasonic attenuation imaging method [1]. In this method, the attenuation coefficients are estimated in a volume, where directly transmitted, reflected, and scattered ultrasonic waves can be recorded - an ultrasonic computer tomography system. All of the recorded signals are used for the attenuation estimation. More information is used for the image reconstruction than in other known approaches; thus the distribution of local attenuation can be reconstructed more accurately. However, this approach has a theoretical limit. It introduces a simplified model of the imaged volume, where only a small number of scatterers / reflectors are assumed. When responses from multiple reflectors / scatterers combine at the receiving transducer, the estimation based on such signal is not correct. In real tissue, obviously, this simplifying assumption can not be guaranteed. The, modifying idea consists in incorporating coherent preprocessing of the recorded signals in a small neighborhood (subarray) of the receiving transducers. By using phased subarray signal processing, the responses from individual reflectors / scatterers can be distinguished, thus overcoming the limitation.

ultrasonic computer tomography, ultrasonic attenuation, filtered backprojection

Filipík, A., Jiřík, R., Jan, J.

13.05.2005

Swedish Society for Medical Engineering and Medical Physics

Umea, Sweden

91-7305-910-2

IFMBE PROCEEDINGS - 13th Nordic Baltic Conference on Biomedical Engineering and Medical Physics

Volume 9, 2005

1680-0737

IFMBE Proceedings

2005

9

French Republic

119

2

http://www.umu.se/conference/nbc2005/Proceedings_13NBC_2005_Umea.pdf