Acoustic Impedance Analysis with Ultra-high Frequency Ultrasound for Fatty Acid Species Identification in NASH Liver NASH

Accurate discrimination of NASH from simple steatsois (fatty liver) is a critical issue in current clinical practice because it may progress to cirrhosis or even liver cancer[1]. Although the precise mechanisms of NASH remain unclear, some reports have shown differences in the content of free fatty acid (FFA) between controls and NASH[2][3]. Thus, an ultrasound-based diagnostic technique of NASH could be developed by assessing the acoustical properties of the FFA. Our final goal is to establish a quantitative diagnosis of NASH using ultrasonography. We focused on acoustic impedance as a possible parameter for this final goal. The aim of this study is the evaluation of the significance of the acoustic impedance measurement using a scanning acoustic microscopy (SAM) in order to investigate how the FFA influences the acoustic properties of liver cells at microscopic level as a first step.