What is the role of Contrast-Enhanced Computed Tomography (CECT) Abdomen in diagnosing and managing duodenal ulcers?

Role of CECT Abdomen in Duodenal Ulcer

CECT abdomen is not a first-line diagnostic tool for uncomplicated duodenal ulcers, but becomes essential when evaluating for life-threatening complications including active bleeding, perforation, or when endoscopy fails or is unavailable.

Primary Indications for CECT in Duodenal Ulcer

Active Bleeding Scenarios

CECT with angiography (CTA) should be performed when endoscopy fails to achieve hemostasis or when the patient is unsuitable for endoscopy. 1

• CTA can localize active bleeding by detecting contrast extravasation in the duodenum, appearing as high-attenuation material that changes in size and density between arterial and venous phases 1
• In ongoing bleeding, CTA is indicated after negative endoscopy or when endoscopy cannot identify the bleeding site 1
• CTA should be considered if no emergency gastroenterology coverage is available 1
• The imaging guides subsequent catheter angiography for embolization, with technical success rates up to 95% 1

Suspected Perforation

CECT is the key imaging modality in the emergency setting to detect perforation, with sensitivity of 93-96% and specificity of 93-100%. 1, 2

• CT can identify pneumoperitoneum, unexplained intraperitoneal fluid, bowel wall thickening, mesenteric fat stranding, and extraluminal contrast 1
• Plain radiography detects free air in only 30-85% of perforations, making CT superior when peritoneal signs are present 1
• Up to 12% of perforations may have normal CT; triple contrast CT (oral water-soluble contrast via nasogastric tube) improves sensitivity 1
• Perforation carries up to 30% mortality if treatment is delayed, making prompt CT imaging critical 3

Atypical or Complicated Presentations

CECT should be performed when duodenal lesions show ulceroproliferative features, as malignancy is now the most common cause of gastric outlet obstruction in adults. 3

• Thickened edematous mucosa, polypoid lesions, and ulceroproliferative changes extending across multiple walls are atypical for simple peptic ulcer disease 3
• CT findings help differentiate between severe complicated ulcer disease versus neoplasm 3
• Never assume benign peptic ulcer disease without histologic confirmation when ulceroproliferative features are present 3

Abscess or Fistula Detection

Contrast-enhanced CT is the most sensitive and specific test for detecting extra-luminal complications including abscesses and fistulae. 1

• CT helps guide decision-making for immediate surgery versus initial conservative management 1
• Small abscesses (<3 cm) may be treated with antibiotics alone, while larger abscesses require percutaneous drainage or surgery 1

When CECT is NOT Indicated

Uncomplicated Duodenal Ulcer

• Endoscopy (esophagogastroduodenoscopy) remains the gold standard for diagnosing uncomplicated duodenal ulcers 1
• Plain radiography may suffice in peripheral hospitals when free air is detected with clear peritoneal signs 1
• Ultrasound has limited capacity to identify the site and cause of perforation, with sensitivity of only 88% for obstruction 2

Critical Clinical Pitfalls

Do not delay CT imaging or surgical consultation if peritoneal signs develop, as perforated ulcer mortality increases significantly with delayed diagnosis. 3

• Medical stabilization should occur simultaneously with imaging, not sequentially 1
• Renal and coagulation status should be optimized before contrast administration 1
• If CT is unavailable, refer stable patients to a facility with 24/7 emergency imaging 1
• Point-of-care ultrasound can serve as a bridge when CT is unavailable, detecting free fluid, abscesses, or intestinal distention 1

Algorithmic Approach

1. Stable patient with typical ulcer symptoms: Endoscopy first 1
2. Active bleeding with failed endoscopy: CTA followed by catheter angiography 1
3. Peritoneal signs or suspected perforation: Immediate CECT 1, 2
4. Ulceroproliferative features on endoscopy: CECT to evaluate for malignancy or complicated disease 3
5. Recurrent bleeding after initial endoscopic success: CTA if repeat endoscopy unsuccessful or not recommended 1