Balthazar CT Severity Index

CT grading of acute pancreatitis — morphology grade plus necrosis

CT grade

A — normal pancreas

B — focal or diffuse gland enlargement

C — grade B + peripancreatic inflammatory changes

D — one peripancreatic fluid collection

E — ≥ 2 collections and/or gas in or near the pancreas

Pancreatic necrosis

None

< 30%

30–50%

> 50%

Evidence

Original publication

Balthazar EJ, Robinson DL, Megibow AJ, Ranson JHC. Acute pancreatitis: value of CT in establishing prognosis. Introduced the CT severity index (morphology grade A–E plus the extent of necrosis on contrast-enhanced CT, summed 0–10) in 88 patients: necrosis was associated with 23% mortality and an 82% complication rate, versus 0% mortality and 6% morbidity without necrosis.

Radiology, 1990

Open source

Guideline

CT is not required to diagnose acute pancreatitis and is usually unnecessary in the first 48–72 hours unless the diagnosis is uncertain or the patient fails to improve — pancreatic necrosis is often not yet demarcated on an early scan. Combine the CTSI with a clinical severity score (BISAP, Ranson) and the patient’s trajectory rather than using it alone to guide early management.

Last reviewed: 2026-09

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MedScore is an educational and clinical decision-support tool. It does not provide a diagnosis, a treatment, or a drug-dosing recommendation, and it does not replace clinical judgement or local guidelines. Confirm every result against the original source before acting on it. The treating clinician remains responsible for all decisions.