Modified CTSI • Pancreatitis Imaging Index
Apply the radiological findings from the contrast-enhanced CT report to visualize the MCTSI severity profile.
Guidelines & Evidence
Verified
Last Review: 2026-07-17
When to Use
When to Use
Refined prognostic assessment of acute pancreatitis after the initial 72 hours
To overcome the limitations of the original CTSI (Balthazar) in predicting extrapancreatic complications
To quantify pancreatic necrosis and detect inflammatory fluid collections
To assess the risk of developing systemic organ failure and prolonged hospitalization
Timing and Contrast
Ideally performed 3–5 days after onset. A contrast-enhanced CT (CECT) is mandatory to assess "lack of enhancement" (necrosis).
How it Works
The 3 Scoring Categories (Max 10 Points)
01
Pancreatic Inflammation (0, 2, or 4 pts): Normal, oedematous, or with fluid/necrosis.
02
Pancreatic Necrosis (0, 2, or 4 pts): None, ≤ 30%, or > 30%.
03
Extrapancreatic Complications (2 pts): Pleural effusion, ascites, vascular or GI complications.
Severity Categories
| Mild | 0–2 Points |
| Moderate | 4–6 Points |
| Severe | 8–10 Points |
Clinical Pearls
mCTSI vs. Original CTSI
The modified CTSI (Mortele et al., 2004) simplified the grading of necrosis (30% cutoff vs. the original 33/50% cutoffs) and added a dedicated category for extrapancreatic findings. Studies suggest that mCTSI is a significantly better predictor of the duration of hospital stay and the development of multi-organ failure (MOF).
The 30% Threshold
Extensive necrosis (> 30%) on mCTSI is the primary driver of infected pancreatic necrosis and "walled-off necrosis" (WON) later in the disease course.
Clinical Pearls
Presence of extrapancreatic fluid (e.g., pleural effusion) is a direct biomarker of the "systemic capilliary leak" syndrome
A high mCTSI score (> 8) correlate with a nearly 100% complication rate
mCTSI does not include "gas bubbles" (infected necrosis) — this diagnosis remains clinical and radiological (air-fluid levels on CT)
Next Steps
Management Priority
01
mCTSI ≥ 8: ICU Step-down; Aggressive nutrition (ideally enteral); Monitor for sepsis/fever flares.
02
Moderate (4–6): Routine ward care with serial BUN/Cr monitoring to ensure no secondary organ failure.
Complementary Scoring
Original CTSI (Balthazar)
BISAP Score (Acute Pancreatitis)
Revised Atlanta Classification (CP/AP)
The Evidence
The Defining Paper
A modified CT severity index for evaluating acute pancreatitis: improved correlation with patient outcome.
Mortele KJ et al. • American Journal of Roentgenology (AJR). 2004;183(5):1261-5. Comparison with Balthazar index showing improved outcomes prediction.
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Origins & History
Koenraad J. Mortele
Developed by Dr. Mortele at Harvard Medical School. The goal was to modernize the Balthazar criteria, which had been criticized for being "pancreas-centric" and missing the systemic inflammatory burden (pleural effusions/ascites) that actually drives mortality.
Last Comprehensive Review: 2026-07-17