Correlation of ultrasound attenuation with proton density fat fraction across multiple organs in healthy volunteers

BACKGROUND: Local determination of the attenuation in biological tissues has been the focus of extensive research over the past decades. Its characterization is of major interest for both noninvasive thermal therapies and diagnostic applications. Numerous ultrasound (US)-based methods have been investigated in recent years to assess attenuation in vivo. PURPOSE: In this article, we aim to map US attenuation in four organs of human volunteers: liver, pancreas, kidney, and breast. We propose to compare the mean attenuation values obtained in each tissue with the corresponding proton density fat fraction (PDFF) derived from quantitative magnetic resonance imaging (qMRI). This comparison allows us to (i) present a direct calculation method of the local US attenuation and (ii) investigate the relationship between the average fat content of each organ and its global US attenuation. METHODS: . RESULTS: ). When each organ was considered separately, no significant correlation was observed between PDFF average values and global US attenuation, as variations between volunteers were found of the same order of magnitude as the standard deviation around each average value. CONCLUSIONS: This work presents an alternative method for in vivo characterization of US attenuation based on the emission of a plane wave, and highlights the impact of fat density on inter-organ attenuation variations. Together, these results provide new insights into the relationship between tissue microstructure and US attenuation.