Beyond Confounders: Addressing Source of Measurement Variability and Error in Shear Wave Elastography

Chronic liver disease is a major problem in the general population and there is an unmet need to diagnose(and screen) for liver disease with using noninvasive, cost-effective and sensitive techniques.The investigators hypothesize that variation using ultrasound elastography for the estimation of stage of liver fibrosis and steatosis in patients with diffuse liver disease exists due to different methods of measurements, and/or different systems. The proposed investigation is a cross-sectional study using ultrasound elastography and fat quantification modalities. The investigators are planning to enroll 30 subjects 18 years old and older in whom diffuse liver disease is suspected, and who have undergone non-focal liver biopsy in the past 6 months or are scheduled to undergo biopsy within 3 months of enrollment, as part of their routine clinical care. The investigators will use 4 different ultrasound devices with their shear wave elastography and speed of sound functions. Specific aims; * Compare shear wave elastography(SWE) measurements from different ultrasound systems; using histopathology as reference standards. * Assess intra-operator and inter-operator reliability by measuring variability in elastography values by two operators on a single system. * Determine the effect of deviations from guidelines(less number of measurements and measurements during active breath)