One of the main but still unsolved problem in Hepatology is the non-invasive diagnosis and identification of the aggressive form of NAFLD (non-alcoholic liver disease) since there is no single diagnostic tool available that can at the same time quantify fat, fibrosis and inflammation. The goal of this research project therefore is to overcome this drawback by adding a novel diagnostic modality - the measurement of speed of sound (SpOSo) - to the existing ultrasound features (classical ultrasound and elastography). SpOSo depends strongly on the fat content, but is less dependent on fibrosis, which can be diagnosed by elastography. The hypothesis is that SpOSo alone will allow us to quantify steatosis and will therefore be able to diagnose NASH (non-alcoholic steato-hepatitis). Furthermore, SpOSo can potentially provide novel information on inflammation, which is currently not available. We thus believe that the combination of SpOSo and elastography will provide a complete ground breaking ultrasound biopsy replacing invasive liver biopsies in patients with NAFLD, so saving patient discomfort and improving personalized therapeutic decisions.