Total attenuation estimation with model-based diffraction factor in Synthetic Transmit Aperture ultrasound imaging

<p dir="ltr">Total attenuation quantifies the cumulative loss of ultrasound energy due to absorption and scattering as waves propagate through tissue. Accurate estimation of this parameter from backscattered radiofrequency (RF) data is critical for quantitative ultrasound (QUS) applications but is challenged by frequency-dependent diffraction, especially from out-of-plane beam spreading. In this work, we propose a spectral attenuation method that compensates for elevational diffraction without relying on reference phantoms. By incorporating a model-based correction derived from rectangular aperture theory into the spectral reference, we improve frequency alignment and reduce depth- and geometry-induced bias. This approach enables robust, calibration-free estimation of total attenuation, with improved agreement to ground-truth values across depth.</p>