Reconstruction of frequency dependent attenuation using 3D ultrasound tomography

3D Ultrasound tomography enables the reconstruction of quantitative attenuation volumes, however mostly neglecting the frequency dependent aspect. This paper introduces a method to reconstruct the parameters alpha_0 and y of the power absorption law. Attenuation factors for several sub-bands are detected on signal level with an FFT and STFT based methods. Volumes are then reconstructed with a ray based reconstruction per frequency sub-band. To derive alpha_0 and y, a voxel based fit is applied. The validation with simulated data shows good agreement with the ground truth by having an RMSE of 0.08 dB/cm/MHz for alpha_0 and 0.06 for y. The influence of reflection losses was tested with k-Wave simulations: an increased contrast in acoustic impedance leads to artifacts in alpha_0 and y images. First reasonable results with experimental data of a gelatine and PVC phantom are presented. The new method provides a diagnostic tool since the reconstruction of the absorption coefficient alpha_0 and the exponent y carry information which is tissue dependent.