To quantitatively analyze the T2* values of the head, body, and tail of normal pancreas, and observe the value of GRE T2*-weighted MRI in the diagnosis of acute pancreatitis and the relationship between the T2* value and the severity of AP.

1. We design a prospective study about "Magetic Resonance Imaging Study of Acute Pancreatitis".
2. We apply for an account and register our study on the clinicalTrials.
3. In patients with acute pancreatitis, imaging is recommended to confirm the clinical diagnosis, investigate the etiology, and grade the severity of the disease . MR had the excellent resolution of soft tissue，and it has earned an ever more important role in the diagnosis of AP. With the continuous development of MR scanning techniques, the sequence of a multi-echo gradient recalled echo (GRE) T2*-weighted imaging (T2*WI), which acquires a spin echo signal, T2* relaxation acquires a gradient echo signal, is a relatively new MRI technique. The sequence of a GRE T2*WI requires high uniformity of the magnetic field, plus it can provide the T2* value, which can indirectly reflect changes in tissue biochemical components, thus it can be used for the early diagnosis quantitative diagnosis of some diseases .
4. This calculation process for T2* value is completed using post-processing software on the workstation(Advantage workstation 4.4; GE Halthcare) directly after scanning.
5. AP is a process of inflammation diffusion, in which cell edema will lead to hydrogen proton increase. In the inflammatory exudation process, T2* value will change. So we conduct our research. In this study, we will observe pancreas in the normal pancreas and AP, and discuss the relationship between T2* value and that of AP graded by the MR severity index (MRSI) and Acute Physiology And Chronic Healthy Evaluation II (APACHE II) scores.
6. However, until now, there is no research on the sequence applied in the patients with AP.

Inclusion Criteria:

• acute onset of abdominal pain;
• pancreatitis at first onset;
• three-fold elevated amylase or lipase, excluding other causes of elevated enzymes; and
• abdominal MR examination.

Exclusion Criteria:

• inability to cooperate when MR imaging was performed;
• a history of chronic pancreatitis;
• AP due to pancreatic carcinoma;
• hypoproteinemia;
• with hypoproteinemia and other peritoneal/ retroperitoneal infection diseases ;
• with iron deposition disorder (e.g. diabetes or blood system diseases).

Patients with AP admitted to our institution between August 2013 and March 2015 were considered for inclusion in this study. The inclusion criteria for patients in this study were as follows: (a) acute onset of abdominal pain; (b) pancreatitis at first onset; (c) three-fold elevated amylase or lipase, excluding other causes of elevated enzymes; and (d) abdominal MR examination.

6 months

Some diseases, such as chronic anemia, diabetes, etc., may lead to iron deposition in pancreas and may lead to change the T2* value.