Ultrasound Derived Fat Fraction (UDFF) Evaluation of Metabolic Related Fatty Liver Disease (MAFLD) in obesity Patients Metabolic fatty liver disease (MAFLD), formerly known as Nonalcoholic Fatty Liver Disease (NAFLD), is the most common chronic liver disease in the world at present, with a incidence rate of about 30%. In the United States, NAFLD is the third leading cause of hepatocellular carcinoma, and early assessment and diagnosis of liver steatosis characteristics are crucial for timely treatment or intervention to reduce the risk of liver fibrosis and inhibit disease progression. Liver biopsy is considered as the "gold standard" for evaluating, grading, and determining inflammatory activity of liver steatosis and fibrosis. However, liver biopsy are invasive and pathological evaluation differences among observers, which makes it difficult to widely use and repeat, especially for dynamic evaluation of patients during the treatment process.
Ultrasound Derviced Fat Fraction (UDFF) is a unique technology for non-invasive quantification of liver fat content, which is equipped on the Siemens ACUSON Sequoia ultrasound system. UDFF is calculated from two parameter values: attenuation coefficient (AC) and backscatter coefficient (BSC). SWE (shear wave elastography) is becoming widely used, and is recommended for the evaluation of liver fibrosis by some guidelines in patients with chronic liver diseases, such as viral hepatitis. These two technologies (UDFF+SWE) can be achieved on the same probe, and this detection technology is non-invasive, painless, simple, and reliable.
Bariatric surgery (BS), also known as metabolic weight loss surgery, is currently recognized as the most significant and long-lasting method for treating obesity. It can significantly improve obesity related comorbidities, as well as long-term improvement in postoperative quality of life and mental state.
This study will aim on analysis of the liver ultrasound characteristics of patients who plan to undergo bariatric surgery. By using UDFF and elastic shear wave technology (UDFF+SWE), a new non-invasive ultrasound evaluation method for MAFLD grading diagnosis of simple fatty liver, fatty hepatitis, liver fibrosis, and related cirrhosis will be proposed, and the incidence and risk factors of MAFLD in overweight and obese patients will be explored, The reversal effect of weight loss therapy on MAFLD in obese patients.