CT Severity Index (CTSI, Balthazar) — free guideline decision tool
Grade acute pancreatitis severity on CT with the Balthazar CT Severity Index.
Open guideline tool →Guideline-based
Implements the decision logic from published clinical guidelines.
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No installation. Enter the patient's values and get a guideline recommendation instantly.
Data stays local
Nothing is uploaded. Results are for licensed clinicians only.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Balthazar CT grade | A (0): normal pancreas |
|---|---|
| Extent of pancreatic necrosis | No necrosis (0) |
→CTSI0/10
- Band：0 → Mild (0–3 mild, 4–6 moderate, 7–10 severe); higher scores carry higher complication and mortality rates
- Timing：Contrast-enhanced CT is best assessed > 72 h after symptom onset (earlier underestimates necrosis); necrosis requires contrast-enhanced CT (reduced enhancement)
- Note：The modified CTSI (Mortele) simplifies necrosis grading and adds extrapancreatic complications (+2); this tool uses the classic Balthazar CTSI (grade 0–4 + necrosis 0/2/4/6)
| Balthazar CT grade | E (4): ≥ 2 collections or retroperitoneal gas |
|---|---|
| Extent of pancreatic necrosis | > 50% (6) |
→CTSI10/10
- Band：10 → Severe (0–3 mild, 4–6 moderate, 7–10 severe); higher scores carry higher complication and mortality rates
- Timing：Contrast-enhanced CT is best assessed > 72 h after symptom onset (earlier underestimates necrosis); necrosis requires contrast-enhanced CT (reduced enhancement)
- Note：The modified CTSI (Mortele) simplifies necrosis grading and adds extrapancreatic complications (+2); this tool uses the classic Balthazar CTSI (grade 0–4 + necrosis 0/2/4/6)
Common questions
What is CT Severity Index (CTSI, Balthazar)?
Grade acute pancreatitis severity on CT with the Balthazar CT Severity Index.
How is CT Severity Index (CTSI, Balthazar) calculated? What is the core formula?
CTSI = Balthazar grade (A–E = 0–4) + necrosis extent (0/2/4/6), total 0–10. 0–3 mild, 4–6 moderate, 7–10 severe.
When is CT Severity Index (CTSI, Balthazar) used?
Assess prognosis in acute pancreatitis from imaging.
What are the key clinical points for CT Severity Index (CTSI, Balthazar)?
Assess contrast-enhanced CT > 72 h after onset to avoid underestimating necrosis. Higher scores carry higher complication and mortality rates. The modified CTSI (Mortele) adds extrapancreatic complications.
What are the limits and cautions when using CT Severity Index (CTSI, Balthazar)?
For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
How is CT Severity Index (CTSI, Balthazar) calculated in practice? Can you show a worked example?
Inputs: Balthazar CT grade A (0): normal pancreas, Extent of pancreatic necrosis No necrosis (0) → Result: CTSI 0 /10（Band: 0 → Mild (0–3 mild, 4–6 moderate, 7–10 severe); higher scores carry higher complication and mortality rates, Timing: Contrast-enhanced CT is best assessed > 72 h after symptom onset (earlier underestimates necrosis); necrosis requires contrast-enhanced CT (reduced enhancement), Note: The modified CTSI (Mortele) simplifies necrosis grading and adds extrapancreatic complications (+2); this tool uses the classic Balthazar CTSI (grade 0–4 + necrosis 0/2/4/6)） Inputs: Balthazar CT grade E (4): ≥ 2 collections or retroperitoneal gas, Extent of pancreatic necrosis > 50% (6) → Result: CTSI 10 /10（Band: 10 → Severe (0–3 mild, 4–6 moderate, 7–10 severe); higher scores carry higher complication and mortality rates, Timing: Contrast-enhanced CT is best assessed > 72 h after symptom onset (earlier underestimates necrosis); necrosis requires contrast-enhanced CT (reduced enhancement), Note: The modified CTSI (Mortele) simplifies necrosis grading and adds extrapancreatic complications (+2); this tool uses the classic Balthazar CTSI (grade 0–4 + necrosis 0/2/4/6)）
Run CT Severity Index (CTSI, Balthazar) now
Grade acute pancreatitis severity on CT with the Balthazar CT Severity Index.
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
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