This study intends to construct the linear relationship between pancreatic volume and individual attributes (height, weight, width of anterior superior iliac spine, etc.), and to establish and verify the formula of pancreatic volume.

The volume of pancreas in healthy individuals changes with age. The pancreatic volume gradually increases from birth to 20 years old. There is a plateau period from 20 to 60 years old, and the volume gradually decreases after 60 years old. With the development of imaging technology, pancreatic volume can be measured by computer tomography and magnetic resonance imaging.

Whether it is pancreatic atrophy after chronic pancreatitis or pancreatic edema after acute pancreatitis, the pathological changes of pancreatic parenchyma may lead to changes in pancreatic volume. Many studies have confirmed that pancreatic volume can be used to evaluate the course of pancreatic related diseases such as diabetes and acute pancreatitis.

Therefore, the establishment of accurate and convenient pancreatic volume formula can help to estimate the initial pancreatic volume of patients. This study is helpful to evaluate the clinical stage, severity and prognosis of pancreatic related diseases.

Inclusion Criteria (Meet 1 or 2 or 3):

• Healthy individuals (excluding pancreatic related diseases, such as acute and chronic pancreatitis, pancreatic trauma, pancreatic tumor, peripancreatic lesions, diabetes and other diseases that may affect the volume of the pancreas);
• Patients with chronic pancreatitis;
• Patients with acute pancreatitis within 144 hours after the onset of typical symptoms (severe persistent epigastric pain).

Exclusion Criteria:

• suspected to have malignant tumors;
• History of pancreas related surgery or minimally invasive treatment (such as pancreaticoduodenectomy, ERCP, etc.);
• acute exacerbation of chronic pancreatitis;
• pregnant or breastfeeding women;
• patients who refused to participate in the study.

Inpatients meeting the eligibility criteria.