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CT Severity Index (Balthazar) for Acute Pancreatitis

The CT Severity Index adds the Balthazar grade (A–E, 0–4 points) to the extent of pancreatic necrosis (none 0, ≤30% 2, 30–50% 4, >50% 6) for a 0–10 score: 0–3 mild, 4–6 moderate, 7–10 severe acute pancreatitis.

Balthazar CT grade: A: normal pancreas (0); B: focal or diffuse enlargement (1); C: pancreatic inflammation / peripancreatic fat stranding (2); D: single peripancreatic fluid collection (3); E: ≥2 collections or retroperitoneal gas (4)
Pancreatic necrosis: None (0); ≤ 30% (2); 30–50% (4); > 50% (6)

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Interpretation

Result	Meaning
0–3	Mild
4–6	Moderate
7–10	Severe

Formula

CTSI = Balthazar grade (A 0, B 1, C 2, D 3, E 4) + necrosis (none 0, ≤30% 2, 30–50% 4, >50% 6)

Clinical pearls

Contrast CT is most informative 72–96 h after onset; early CT underestimates necrosis.
The modified CTSI (Mortele 2004) rescores necrosis and adds extrapancreatic complications; this is the original Balthazar version.

Examples

ctsi balthazar grade E with >50% necrosis ct severity index grade C no necrosis balthazar D, necrosis 30-50%

FAQ

What CT severity index is severe?

A score of 7–10 indicates severe pancreatitis, with about 17% mortality and 92% morbidity in Balthazar's series.

When should CT be done in acute pancreatitis?

Not routinely at admission; after 72 hours if the patient fails to improve, when necrosis can be assessed.

Evidence

Balthazar EJ et al. Acute pancreatitis: value of CT in establishing prognosis. Radiology 1990;174:331–6.

Hepatology & GI · Reviewed 2026-10-14 · Methodology