UGI Imaging Framework

✴ UGI Imaging Framework

CT Evaluation of Stomach and Duodenum

✍ Created by Dr. Sharad Maheshwari MD - imagingsimplified@gmail.com

A Case-Based, Surgeon-Oriented Radiology Framework

Welcome to the interactive upper gastrointestinal (UGI) imaging framework. This application is designed to transition radiology practice from descriptive reporting to actionable clinical decision support. Evaluation of stomach and duodenal pathology is frequently underestimated in complexity, leading to critical diagnostic errors.

This section outlines the core systemic issues underlying diagnostic failures and introduces our structured approach. By integrating clinical presentation, imaging morphology, and surgical implications, radiologists can drastically reduce misses of occult perforations, early malignancies, and duodenal pathologies.

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Non-standardized Evaluation

Lack of a systematic approach to distinct segments of the stomach and duodenum leads to anatomical blind spots.

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Pattern Over-reliance

Relying solely on visual pattern recognition without integrating the patient's acute clinical context limits accuracy.

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Endpoint Disconnect

Failure to emphasize the specific findings that dictate surgical decision-making and patient management endpoints.

Framework Composition

This framework divides pathologies into five clinical categories. The distribution emphasizes acute emergencies and neoplastic conditions which require the highest precision.

Role of Imaging Modalities

While CT is the workhorse, a comprehensive UGI evaluation often relies on a multi-modality approach. Select a modality to understand its specific utility, strengths, and limitations in gastric and duodenal imaging.

Surgical Anatomy: What Matters on CT

Radiologic interpretation must align with functional surgical anatomy, not just textbook segmentation. Select a segment to view its radiologic vulnerabilities. Core Principle: A collapsed stomach is a diagnostic failure, not a normal finding.

Gastric Segments

Duodenal Segments

STOMACH

Body / Fundus

This highly expansile region is prone to underdistension during routine CT acquisitions.

⚠ Critical Pitfall

Inadequate distension creates pseudothickening, easily masking early neoplastic lesions or simulating false pathology.

CT Protocols by Clinical Scenario

Phase selection and oral contrast depend heavily on the suspected etiology.

Pathology Explorer

Pathology is organized by clinical urgency to reflect real-world surgical workflows.

⚠ Acute Surgical Emergencies

1. Perforated Peptic Ulcer

Imaging Features

• Pneumoperitoneum (may be subtle/absent)
• Focal wall discontinuity
• Adjacent fat stranding

Surgical Relevance

Determine site, leak evidence, and contamination extent.

Pitfall: Absence of free air does NOT exclude perforation.

2. Gastric Outlet Obstruction (GOO)

Differentiating Benign vs Malignant etiology guides stenting vs resection.

3. SMA Syndrome

Criteria: Reduced aortomesenteric angle & distance, with proximal dilation. Pitfall: Overdiagnosis in low BMI patients without symptoms.

Inflammatory and Ulcerative

4. Peptic Ulcer Disease

Red Flags for Malignancy

• Nodular margins
• Asymmetric thickening
• Loss of wall stratification

CT triggers endoscopic confirmation, not definitive labeling.

5. Gastritis & Duodenitis

CT findings include diffuse thickening and mucosal hyperenhancement. CT is largely nonspecific for mucosal disease. Avoid overdiagnosis.

Neoplastic Pathology

6. Gastric Adenocarcinoma

Staging Priorities: Depth, Nodes, Metastases. Radiologist must determine resectability (serosal/adjacent organ invasion).

7. GIST

Exophytic, hypervascular, central necrosis. Guides targeted therapy (imatinib).

8. Lymphoma

Misclassification as carcinoma leads to unnecessary surgery.

Look for: Long segment, homogeneous thickening, minimal obstruction, preserved fat planes.

Vascular & Ischemic

9. Gastroduodenal Ischemia

Life-threatening pathology requiring urgent intervention.

Features: Reduced wall enhancement, pneumatosis, portal venous gas.

Congenital & Mimics

10. Annular Pancreas

Recognize as a cause of duodenal obstruction (encircling tissue).

11. Duodenal Diverticulum

Pitfall: May mimic perforation due to intraluminal air-fluid levels. Confirm luminal continuity.

High-Yield Pitfalls & Reporting

Understanding where diagnostic errors occur is critical. Compare clinical risk severity below and utilize the mandatory reporting framework.

Diagnostic Pitfalls by Clinical Risk Severity

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Surgeon-Oriented Reporting Framework

Every UGI CT report should answer these 5 critical questions.

1

Pathology

What is the exact disease entity?

2

Location

Where is it anatomically anchored?

3

Complications

Is there perforation, leak, or ischemia?

4

Resectability

Vascular or adjacent organ invasion?

5

Urgency

Operative vs. conservative timeline?

🎓 Learning Hub

Reinforce your knowledge through interactive flashcards and test your clinical readiness with the competency evaluation module.

💡 High-Yield Flashcards

Click on a card to flip and reveal the answer.

Most commonly missed duodenal segment on CT?

D4 (Ascending Segment)

Often the critical transition zone in mechanical bowel obstruction.

Oral contrast rule for suspected perforation?

Water-Soluble Only

(e.g., Gastrografin). NEVER use Barium due to risk of severe chemical peritonitis.

Radiologic misclassification that leads to unnecessary surgery in gastric tumors?

Gastric Lymphoma

Misinterpreting lymphoma (treated medically) as adenocarcinoma (surgical).

Competency Evaluation

Test your mastery of the CT evaluation framework. 5 Questions.