Ultrasonic attenuation tomography based on log-spectrum analysis

The paper presents a new ultrasonic attenuation imaging method which might be used as a new imaging modality, targeted at breast cancer diagnostics. Two approaches based on ultrasonic imaging are combined together, namely the estimation of ultrasound attenuation coefficients from pulse-echo B-mode imaging data and an ultrasound computer tomography imaging technique. A recently published method for estimation of the ultrasound attenuation coefficient using the log-spectrum analysis is applied to radiofrequency signals acquired by an ultrasound computer tomography system to estimate images of the attenuation coefficients. The examined volume (e.g. female breast) is enclosed by several thousand ultrasound transducers. Radiofrequency signals from all transducers using all sending positions are recorded. Compared to the known ultrasound attenuation tomography methods, not only the directly transmitted signal, but also the reflected and scattered signals are processed here, i.e. substantially more information is used. The method is presented in its initial stage. The applied algorithm is derived using simplifying assumptions which will be relaxed in further research. However, even at this stage the resulting attenuation image is of higher quality than the standard attenuation imaging methods applied to the same data set.