Reconstruction of ultrasonic sound velocity and attenuation coefficient using linear arrays: Clinical assessment
Journal
Proceedings - IEEE Ultrasonics Symposium
Journal Volume
1
Pages
2152-2155
Date Issued
2006
Author(s)
Abstract
The aim of this study was to determine the efficacy of using the sound velocity and tissue attenuation to clinically discriminate breast cancer from healthy tissues. The methods for reconstructing the sound-velocity and attenuation-coefficient distributions were previously proposed and tested on tissue-mimicking phantoms. The methods require only raw channel data acquired by a linear transducer array, and therefore can be implemented on existing clinical systems. In this paper, these methods are tested on clinical data. A total of 19 biopsy-proven cases, consisting of 5 carcinomas (CAs), 7 fibroadenomas (FAs), 6 adipose tissue (fat), and 1 oil cyst, were evaluated. A single imaging setup consisting of a 5-MHz, 128-channel linear array was used to simultaneously obtain B-mode image data, time -of-flight data, and attenuation data. The sound velocity and attenuation coefficient can be reconstructed inside and outside a region of interest manually selected in the B-mode image. To reduce distortion caused by tissue inhomogeneities, an optimal filter derived from pulse-echo data - with water replacing the breast tissue - is applied. We found that the sound velocities in CA, FA, and fat tissues relative to those in the surrounding tissues were 44.9±35.9, 13.0±40.5, and -55.9±30.9 m/s (mean±SD), respectively, whereas the relative attenuation coe ffi cients were -0.30±0.45, 0.24±1.59, and 0.16±0.64 dB/cm/MHz. These results indicate that CA can be discriminated from FA and fat by choosing an appropriate threshold for the relative sound velocity (i.e., 18.5 m/s). However, the large variations in the attenuation within the same type of tissue make simple thresholding ineffective. Nevertheless, the method described in this paper has the potential to reduce negative biopsies and to improve the accuracy of breast cancer detection in clinics. ? 2006 IEEE.
Subjects
Attenuation; Attenuation coefficient; Region of interest; Sound velocity; Time-of-flight
Other Subjects
Attenuation; Attenuation coefficient; Region of interest; Sound velocities; Time of flight; Acoustic variables measurement; Acoustic wave velocity; Array processing; Biopsy; Histology; Image segmentation; Ultrasonic applications; Ultrasonics; Tissue
Type
conference paper