A 42-year-old man with a history of gallstones presents with acute onset epigastric pain radiating to the back, associated with nausea and vomiting. Serum amylase is elevated at 850 U/L. On clinical examination, he has tenderness in the epigastrium and left upper quadrant. Which investigation is most appropriate to assess the severity of acute pancreatitis and guide further management?

Explanation

## Investigation of Choice for Severity Assessment in Acute Pancreatitis **Key Point:** Contrast-enhanced CT (CECT) abdomen is the gold standard investigation for assessing the severity, extent, and complications of acute pancreatitis, particularly in moderate-to-severe disease. ### Why CECT is Superior **High-Yield:** CECT provides: 1. **Morphological assessment** — pancreatic edema, necrosis, and extent of necrosis 2. **Complication detection** — fluid collections, pseudocysts, peripancreatic fluid 3. **Organ involvement** — splenic infarction, ascites, pleural effusion 4. **Severity grading** — Modified Marshall Score and APACHE II correlation 5. **Prognostic value** — Balthazar score and modified CT severity index (MCTSI) predict mortality and morbidity ### Timing of CECT **Clinical Pearl:** CECT should be performed after 48–72 hours of symptom onset to allow full development of pancreatic necrosis and fluid collections. Early imaging (< 48 hrs) may underestimate necrosis. ### Comparison of Investigations | Investigation | Role | Limitation | | --- | --- | --- | | **CECT** | Severity, necrosis, complications | Radiation, contrast allergy | | **Serum lipase** | Diagnosis only | Does not assess severity | | **Ultrasound** | Biliary pathology, free fluid | Poor pancreatic visualization; operator-dependent | | **ERCP** | Therapeutic (biliary obstruction) | Not diagnostic; invasive; risk of worsening pancreatitis | **Warning:** Serum lipase elevation does NOT correlate with severity — a patient with 10× elevation may have mild disease, while another with 2× elevation may have severe necrotizing pancreatitis. ### Clinical Scenario Application In this case, the patient has: - Elevated amylase (diagnostic of pancreatitis) - Likely biliary etiology (gallstones) - Need for severity assessment to decide on ICU admission, nutritional support, and intervention timing CECT will determine if he has edematous or necrotizing pancreatitis and guide management intensity. **Mnemonic: CECT SEVERITY** — Complications, Extent, Complications, Tissue necrosis / Severity, Evaluation, Vital organ involvement, Etiology confirmation, Rescue intervention planning, Imaging timing (48–72 hrs), Therapeutic decision-making, Yield prognostic score.