Fluid Collections:
| Classification | Description | Notes |
| Acute Peripancreatic Fluid Collections | Extra-pancreatic, homogenous fluid attenuation, no wall | Seen in IEP, occur within 4 weeks of onset |
| Acute Necrotic Collections | Intra- or extra-pancreatic, usually inhomogeneous, no wall | Seen in Necrotizing Pancreatitis, occur within 4 weeks after onset |
| Walled-Off Necrosis | Intra- or extra-pancreatic, inhomogeneous, encapsulating wall | Seen in Necrotizing Pancreatitis, occur more than 4 weeks of onset |
| Pseudocysts
|
Extra-pancreatic, homogenous fluid attenuation, encapsulating wall | Seen in IEP, occur more than 4 weeks after onset |
Any fluid collection may become infected and contain gas
References:
Foster BR, Jensen KK, Bakis G, Shaaban AM, Coakley FV. Revised Atlanta Classification for Acute Pancreatitis: A Pictorial Essay. Radiographics. 2016;36(3):675-87.