Assessing liver fat fraction by ARFI induced shear wave attenuation: A preliminary result

In this pilot study, we investigated an ultrasound-based non-invasive method to assess liver fat content. The proposed ultrasonic measurements were the propagation parameters of shear wave (SW) induced by acoustic radiation force impulse (ARFI). These parameters include attenuation, velocity dispersion, and the bandwidth and center frequency. Ten (10) human adult subjects were enrolled in this pilot study. The fat content in each subject was measured with the MRI proton density fat fraction (PDFF) method, which served as the reference standard. The SW parameters, therefore, were compared and correlated with the PDFF value. The SW attenuation parameter was found to be strongly correlated with MRI PDFF (r = 0.83, p > 0.003); the bandwidth of the SW displacement waveform was also well correlated with the PDFF (r = 0.75, p > 0.01). However, velocity dispersion was not strongly correlated as expected, nor was the center frequency. This preliminary result supports further study to correlate SW attenuation with biopsy-determined steatosis grade in a larger cohort of subjects.