Table 3.

CT Severity Index (Modified from: Balthazar EJ, Robinson DL, Megibow AJ, Ranson JH. Acute pancreatitis: value of CT in establishing prognosis. Radiology. 1990; 174:331–6 [27])

CT grade	Grade score	Definition
A	0	Normal pancreas
B	1	Pancreatic enlargement
C	2	Pancreatic inflammation and/or peripancreatic fat
D	3	Single peripancreatic fluid collection
E	4	≥ 2 fluid collections and/or retroperitoneal air
% of necrosis	Necrosis score	Definition
None	0	Uniform pancreatic enhancement
< 30%	2	Non-enhancement of region(s) of gland equivalent in size of pancreatic head
30–50%	4	Non-enhancement of 30–50% of the gland
> 50%	6	Non-enhancement of over 50% of the gland
CT Severity Index	Morbidity	Mortality
0–1	0	0
2–3	8%	3%
4–6	35%	6%
7–10	92%	17%

CT severity Index = grade score (0–4) + necrosis score (0–6)