CT severity index (CTSI)

The CT severity index (CTSI) is based on findings from a CT scan with intravenous contrast to assess the severity of acute pancreatitis. The severity of computed tomography findings have been found to correlate well with clinical indices of severity.

The CTSI sums two scores:

• Balthazar score: grading of pancreatitis (A-E) 
• grading the extent of pancreatic necrosis

The necrosis scoring system was added to the traditional Balthazar score in the 1990 by the same author.

Modifications have been made to the CTSI, resulting in the Modified CTSI (2004).

CTSI

Grading of pancreatitis (Balthazar score)

• A: normal pancreas: 0
• B: enlargement of pancreas: 1
• C: inflammatory changes in pancreas and peripancreatic fat: 2
• D: ill-defined single peripancreatic fluid collection: 3
• E: two or more poorly defined peripancreatic fluid collections: 4

Pancreatic necrosis 

• none: 0
• ≤30%: 2
• >30-50%: 4
• >50%: 6

The maximum score that can be obtained is 10.

Treatment and prognosis

The CTSI is the sum of the scores obtained with the Balthazar score and those obtained with the evaluation of pancreatic necrosis:

• 0-3: mild acute pancreatitis
• 4-6: moderate acute pancreatitis
• 7-10: severe acute pancreatitis

There is good correlation of clinical pancreatitis scores and imaging pancreatitis scores, so imaging is not always necessary to assess the severity of pancreatitis .

Siehe auch:

• Pankreatitis
• Balthazar score