Is an abdominal X-ray (X-ray) sufficient for diagnosing intussusception?

Ultrasound is the Preferred Diagnostic Imaging Modality for Intussusception, Not X-ray

Abdominal X-ray is not sufficient for diagnosing intussusception and should not be used as the primary diagnostic tool. Ultrasound is the recommended first-line imaging modality for suspected intussusception due to its high sensitivity and specificity.

Diagnostic Accuracy of Imaging Modalities for Intussusception

Ultrasound vs. X-ray

• Ultrasound has significantly superior diagnostic performance:

  • Sensitivity: 97.9% (95% CI, 95%-100%)
  • Specificity: 97.8% (95% CI, 97%-99%) 1

• X-ray has poor diagnostic performance:

  • Sensitivity: only 48% (95% CI, 44%-52%)
  • Specificity: only 21% (95% CI, 18%-24%) 1

Why X-ray is Inadequate

• Abdominal radiographs can be misleading in 20-40% of patients 2
• X-ray findings are often non-specific and may miss the diagnosis entirely
• Even when X-ray findings are "highly suggestive," additional confirmation is typically required

Evidence-Based Recommendations

Pediatric Patients

• Ultrasound should be the first imaging study performed in children with suspected intussusception
• Recent research explicitly states: "Abdominal radiography is not recommended for the diagnosis of intussusception in children" 3
• In the pediatric population, ultrasound has proven useful specifically for evaluating intussusception 2

When X-ray Might Be Considered

• X-ray should be reserved only for:
  • Children with clinical evidence of peritonitis and suspected perforation
  • Cases where clinical findings are unusual
  • When sonographic examination is equivocal 4
  • To rule out pneumoperitoneum if perforation is suspected

Diagnostic Algorithm for Suspected Intussusception

1. Initial Evaluation: Clinical assessment for classic triad (abdominal pain, vomiting, bloody stools)

2. First-line Imaging: Ultrasound

   • High sensitivity and specificity (>97%)
   • No radiation exposure
   • Can visualize the characteristic "target" or "pseudokidney" sign
   • Can assess reducibility and identify lead points

3. If Ultrasound is Unavailable or Inconclusive:

   • CT scan provides excellent visualization but involves radiation exposure
   • MRI is an alternative in specific situations (no radiation)

4. Role of X-ray:

   • Limited to cases where perforation is suspected
   • Should not delay appropriate treatment if clinical signs of peritonitis are present 2
   • Not recommended as a standalone diagnostic tool for intussusception

Treatment Considerations

• Once diagnosed, pneumatic (gas) reduction is superior to hydrostatic (liquid) reduction:
  • Success rate of gas enema: 82.7% (95% CI, 79.9%-85.6%)
  • Success rate of liquid enema: 69.6% (95% CI, 65.0%-74.1%) 1

Common Pitfalls to Avoid

• Relying solely on X-ray for diagnosis, which can lead to missed cases
• Delaying ultrasound in favor of less accurate imaging
• Failing to recognize that the classic clinical triad is often incomplete
• Overlooking the time-dependent nature of symptoms (bloody stools typically appear later, at a median of 24 hours) 5

In conclusion, while abdominal X-rays have traditionally been used in the diagnostic workup of intussusception, current evidence strongly supports ultrasound as the imaging modality of choice due to its superior diagnostic accuracy, lack of radiation exposure, and ability to guide therapeutic interventions.