Ultrasound attenuation tomography for breast cancer detection Seminar

State-of-the-art UCT systems are able to reconstruct high resolution images of the sound speed of tissue from measurements of the time-of-flight of ultrasound through the breast. However, reconstruction of the attenuation distribution has proven more difficult due the need to determine the amplitude of the received wave, which is highly aberrated due to the heterogeneity of sound-speeds within the breast. Traditional piezoelectric sensors are prone to underestimation of the received amplitude due to spatial averaging across the aberrated wave fronts, as well as their directional response.

We have developed a prototype UCT system that employs a novel, omnidirectional, phase-insensitive ultrasound sensor based on the pyroelectric effect that is immune to spatial averaging and directivity effects, and can therefore generate quantitative maps of attenuation. We have tested the system using commercial breast phantoms, and compared the resulting images with ground-truth attenuation maps generated from X-ray CT images and the known attenuation coefficients of the materials.