How is CT scoring used to assess the severity of acute pancreatitis in children?

CT Scoring for Acute Pancreatitis in Children

Critical Limitation: Pediatric-Specific Evidence Gap

The CT Severity Index (CTSI) and Modified CT Severity Index (MCTSI) described in major guidelines were developed and validated in adult populations, and there is no pediatric-specific CT scoring system validated in the provided evidence. 1 However, these adult scoring systems are commonly applied to pediatric patients in clinical practice due to the lack of alternatives.

The CT Severity Index (CTSI) - Balthazar Score

The CTSI combines two components to predict morbidity and mortality 1:

Component 1: CT Grade (0-4 points)

• Grade A (0 points): Normal pancreas 1
• Grade B (1 point): Pancreatic enlargement 1
• Grade C (2 points): Pancreatic inflammation and/or peripancreatic fat 1
• Grade D (3 points): Single peripancreatic fluid collection 1
• Grade E (4 points): ≥2 fluid collections and/or retroperitoneal air 1

Component 2: Necrosis Score (0-6 points)

• 0 points: No necrosis (uniform pancreatic enhancement) 1
• 2 points: <30% necrosis (non-enhancement equivalent to size of pancreatic head) 1
• 4 points: 30-50% necrosis 1
• 6 points: >50% necrosis 1

Total CTSI Score and Prognosis

The final CTSI = CT Grade Score + Necrosis Score (range 0-10) 1

Prognostic stratification in adults: 1, 2

• CTSI 0-3: 8% morbidity, 3% mortality
• CTSI 4-6: 35% morbidity, 6% mortality
• CTSI 7-10: 92% morbidity, 17% mortality

Optimal Timing for CT Imaging in Children

CT should be performed 72-96 hours after symptom onset, not earlier, to avoid underestimating the extent of pancreatic necrosis. 1, 2, 3 Early CT scans (within 72 hours) have a detection rate of only 90%, reaching nearly 100% sensitivity after 4 days. 2, 3

Indications for CT in Pediatric Acute Pancreatitis

• Predicted severe disease (clinical severity scores suggesting severe pancreatitis) 1
• Evidence of organ failure during the initial 72 hours 1
• Persistent or worsening symptoms after 48-72 hours of hospitalization 3
• Clinical deterioration or failure to show continued improvement 2

Technical Protocol for Pediatric CT

Contrast-enhanced CT (CECT) is the imaging modality of choice for diagnosis, staging, and detection of complications. 1, 2 A proper pancreas protocol requires: 1

• Spiral or multislice CT scanner 1
• Oral contrast: Approximately 500 ml (adjust for pediatric weight) by mouth or nasogastric tube 1
• Intravenous contrast: Essential for detecting necrosis; non-contrast CT provides suboptimal information 1, 4
• Single portal venous phase is sufficient for follow-up imaging, reducing radiation exposure by 36% compared to dual-phase protocols 5, 6

Special Considerations for Pediatric Patients

Radiation Exposure Concerns

MRI is preferable to CECT in young patients to minimize radiation exposure, particularly when multiple imaging studies may be needed. 1, 2 MRI can identify non-liquefied material and necrotic tissue, though it is less sensitive than CT for detecting gas in fluid collections. 1

Alternative Imaging Modalities

• Ultrasound: Should be performed on admission to determine biliary etiology, but cannot replace CT for assessing pancreatic necrosis 3
• MRI without contrast: Suitable alternative for patients with renal impairment 1, 2

Common Pitfalls to Avoid

Do not perform early CT (before 72 hours) routinely, as it frequently shows no necrosis, establishes no alternative diagnoses, and rarely alters clinical management (89.8% of cases), while exposing children to unnecessary radiation. 7

Avoid frequent repeat CT scans, as they increase radiation exposure and have limited effect on subsequent decision-making. 1, 3

Do not withhold contrast due to unfounded concerns about contrast-induced pancreatitis—this is not a recognized complication in major guidelines, and contrast is essential for optimal pancreatic evaluation. 4