What is the recommended initial imaging for a patient with mid upper abdominal pain radiating to the back and vomiting, with laboratory results showing neutrophilia (elevated neutrophil count)?

Recommended Imaging for Mid Upper Abdominal Pain Radiating to Back with Vomiting and Neutrophilia

CT abdomen and pelvis with IV contrast is the recommended initial imaging study for this presentation. 1, 2

Primary Recommendation

Obtain CT abdomen and pelvis with IV contrast as the first-line imaging modality. This presentation of epigastric pain radiating to the back with vomiting raises concern for serious pathology including acute pancreatitis, perforated peptic ulcer, mesenteric ischemia, or in the context of neutrophilia, neutropenic enterocolitis if the patient has recent chemotherapy exposure. 1, 2, 3

Why CT with IV Contrast is Superior

• CT changes diagnosis in 49% of patients with nonlocalized abdominal pain and alters management in 42% of cases, making it far more impactful than clinical assessment alone 1
• Diagnostic accuracy of 96.8% has been demonstrated when CT is performed early in the evaluation of acute abdominal pain 4
• IV contrast is essential because it increases detection of vascular pathology (mesenteric ischemia), inflammatory processes (pancreatitis), and bowel wall enhancement patterns that distinguish ischemia from other conditions 1
• Single-phase IV contrast-enhanced examination is sufficient for initial diagnosis; pre-contrast and delayed phases are not required 2

Clinical Context: Neutrophilia Considerations

The presence of neutrophilia (elevated neutrophil count) significantly narrows your differential diagnosis and increases urgency:

• Neutrophilia combined with lymphopenia and eosinopenia has 94.9% specificity for severe infectious or surgical pathology requiring urgent intervention 5
• Neutrophil count >9.0 × 10⁹/L with lymphopenia (<1.4 × 10⁹/L) and eosinopenia (<0.04 × 10⁹/L) strongly predicts severe illness necessitating immediate imaging 5
• If this patient has recent chemotherapy exposure, consider neutropenic enterocolitis, which primarily affects the cecum and ascending colon but can involve other segments, with mortality risk of 60% when bowel wall thickness exceeds 10 mm 6, 7

Key Differential Diagnoses to Evaluate

Mid-epigastric pain radiating to the back with vomiting specifically suggests:

1. Acute pancreatitis - CT with IV contrast demonstrates pancreatic inflammation, necrosis, and complications 3
2. Perforated peptic ulcer - CT is most sensitive for detecting free intraperitoneal air and identifying the perforation site 8, 3
3. Mesenteric ischemia - CT angiography (which uses IV contrast) is preferred when this is suspected; reduced bowel wall enhancement is 100% specific for bowel infarction 1
4. Ruptured abdominal aortic aneurysm - CT with contrast rapidly identifies this life-threatening condition 3

Why NOT Other Imaging Modalities

Conventional Radiography (X-ray)

• Has limited diagnostic value and rarely changes management in acute abdominal pain 2, 8
• Only potentially useful for obvious bowel obstruction or free air, but CT is more accurate even for these findings 8

Ultrasonography

• Ultrasonography is rated 9/9 (usually appropriate) only for RIGHT UPPER QUADRANT pain with fever and positive Murphy sign (suspected cholecystitis), not for mid-epigastric pain radiating to back 1
• Ultrasound has limited ability to evaluate the pancreas, retroperitoneum, and bowel - all critical areas for this presentation 1
• Operator-dependent with variable sensitivity compared to CT 2

MRI

• MRI can achieve 99% accuracy for abdominal pathology but has longer acquisition times (though modern protocols can be completed in <10 minutes) 1, 2
• Reserve MRI for pregnant patients or when CT findings are equivocal 1, 2
• Not readily available in most emergency settings, making it impractical for acute presentations 1

Critical Pitfalls to Avoid

• Do not order plain abdominal radiographs first - this delays definitive diagnosis and has been surpassed by CT for virtually all acute abdominal conditions 8
• Do not obtain CT without IV contrast - this is rated only 4/9 (may be appropriate) by ACR guidelines and misses critical vascular and inflammatory pathology 1
• Do not assume neutrophilia alone excludes serious pathology - the combination of neutrophilia with specific pain patterns demands urgent imaging 5
• In neutropenic patients (low neutrophil count), avoid endoscopy due to increased perforation risk; rely on CT imaging instead 9, 6
• If bowel wall thickening >10 mm is identified on CT in a neutropenic patient, recognize this carries 60% mortality and requires urgent surgical consultation 6

Scan Coverage

• Include the entire abdomen and pelvis - attempts to limit scan area based on symptoms resulted in missing acute pathology in 67% of abnormal cases 1
• Ensure adequate coverage from diaphragm to pubic symphysis 1