AI-Powered Research

1) Prospective study
- Those scheduled for bariatric surgery due to severe obesity and comorbidities
- Body mass index =30 kg/m2 with comorbid metabolic disease (impaired fasting glucose or glycated hemoglobin >5.7%, diabetes, fatty liver disease, hypertension, triglyceridemia, or at least one of the following: metabolic syndrome) or body mass index = 35 kg/m2
- Age: 19 years of age or older, but not older than 75 years of age
- Determined to be eligible for the study based on a screening physical examination and laboratory tests including serology, hematology, blood chemistry, and urinalysis
- No congenital or treatment-requiring chronic diseases and no pathologic symptoms or findings on internal medicine examination.
- Those who have received a detailed explanation of this study and can fully understand it, and who have voluntarily decided to participate as a research subject and agreed in writing to comply with the precautions.

2) Retrospective study
- Those who underwent bariatric surgery at the Center for Bariatric Metabolism, Gachon University Gil Hospital from March 2018 to March 2022
- Age: 19 years old or older, 75 years old or younger
- Those who underwent liver biopsy during bariatric surgery
- MRI examination before bariatric surgery and 6 months after bariatric surgery

Exclusion Criteria

1) Prospective study
- Age: <19 years, =76 years
- Reoperation patients including gastric band surgery
- Patients who cannot tolerate the noise or isolation environment in the MRI examination room or who are contraindicated for MRI examination (e.g., patients with iron implants or devices in the body, pacemakers, vascular clips, people with artificial devices in the eyes or ears, or other foreign bodies in the body that may be affected by magnetic fields)
- Average daily alcohol consumption exceeding 30 grams (approximately 3 shochu) for men and 20 grams (approximately 2 shochu) for women in the past 5 years and lasting for more than 3 months (approximately 3 or more bottles of shochu for men and 2 or more bottles of shochu for women per week)
- Substance abusers (narcotics)
- History of taking medications that cause secondary fatty liver within the past year (corticosteroids, tamoxifen, amiodarone, methotrexate, etc.)
- Any other identified liver disease: hepatitis B or C, autoimmune hepatitis, drug-induced liver injury, other liver diseases (e.g., anti-trypsin deficiency, primary biliary cirrhosis, primary sclerosing cholangitis, etc.
- Pregnant women
- Any other systemic disease deemed unsuitable for participation in this study.
- Those who are judged to be inappropriate for participation in the study according to the judgment of the principal investigator and the person in charge of the study (physician in charge).

2) Retrospective Study

Exclusion of bariatric metabolic surgeries that do not involve gastric resection, such as gastric banding.
Patients who underwent bariatric metabolic surgery more than once.
Individuals suspected of having fatty liver disease due to reasons other than obesity based on their medical history.
Individuals who consumed alcohol at an average daily intake exceeding 30g for men (approximately 3 shots of soju) and 20g for women (approximately 2 shots of soju) for more than 3 months within the 5 years prior to the surgery date (equivalent to over 3 bottles of soju per week for men and over 2 bottles of soju per week for women).
Other liver and biliary diseases confirmed as of the surgery date: Hepatitis B or C, autoimmune hepatitis, drug-induced liver injury, and other liver diseases (e.g., anti-trypsin deficiency, primary biliary cirrhosis, primary sclerosing cholangitis, etc.).
History of taking drugs known to cause secondary fatty liver within 1 year prior to the surgery date (corticosteroids, tamoxifen, amiodarone, methotrexate, etc.).
History of drug abuse (narcotics).

Study & Design

Study Type: Observational Study

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Evaluate the extent of NAFLD improvement with perioperative weight loss by correlating the extent of fibrosis on histology with liver stiffness measurement (LSM, unit kPa) on MRE examination

Secondary Outcome Measures