From the Guidelines
Diagnosing intussusception primarily involves the use of ultrasound as the initial imaging modality due to its high sensitivity and specificity, as well as its ability to guide potential therapeutic interventions. When considering the diagnosis of intussusception, it's crucial to prioritize methods that offer both high accuracy and the potential for therapeutic intervention. The use of ultrasound in diagnosing intussusception, especially in the pediatric age group, has been highlighted for its effectiveness 1. This approach is supported by the fact that ultrasound can evaluate intussusception with a high degree of accuracy, showing the characteristic "target" or "donut" sign that represents the telescoped bowel.
Key Diagnostic Steps:
- Clinical evaluation to identify symptoms such as intermittent abdominal pain, vomiting, and bloody stools.
- Physical examination to detect a palpable abdominal mass and signs of intestinal obstruction.
- Ultrasound as the preferred initial imaging modality due to its high sensitivity and specificity for intussusception, as noted in the context of evaluating small-bowel obstruction and other gastrointestinal issues 1.
- Consideration of air or contrast enema if ultrasound is inconclusive, which can be both diagnostic and therapeutic.
- Potential use of CT scans in older children or adults when the diagnosis remains unclear, though this is less common for initial diagnosis of intussusception.
Rationale:
The rationale behind prioritizing ultrasound for diagnosing intussusception stems from its non-invasive nature, lack of radiation exposure (particularly important in pediatric patients), and its proven efficacy in visualizing the characteristic signs of intussusception. While CT scans and other imaging modalities like MRI can provide detailed information about the gastrointestinal tract and potential obstructions, ultrasound stands out for its specificity in diagnosing intussusception, especially in pediatric cases 1.
Considerations:
In real-life clinical practice, the choice of diagnostic tool may also depend on availability, patient condition, and the clinical suspicion of intussusception based on presenting symptoms and physical examination findings. However, ultrasound remains the cornerstone for the initial evaluation of suspected intussusception due to its benefits in terms of safety, efficacy, and the potential to guide therapeutic interventions.
From the Research
Diagnostic Methods for Intussusception
- Computed Tomography (CT) scan: CT imaging can help diagnose intussusception by showing a bowel-within-bowel configuration with or without contained fat and mesenteric vessels 2.
- Magnetic Resonance (MR) imaging: MR imaging can also be used to diagnose intussusception, especially in adults, and can provide excellent pre-operative evaluation 2.
- Ultrasound: Ultrasound is an accurate, low-risk screening tool for intussusception, especially when performed and interpreted by an experienced ultrasonographer 3.
- Barium enema: Barium enema is the gold standard for diagnosis and also has therapeutic potential for reducing the intussusception 3.
- Plain film radiography: Plain film radiography can also play a role in the diagnosis of intussusception, especially in children 4.
Clinical Features and History
- Abdominal pain, vomiting, and bloody stools are common presenting symptoms of intussusception, but this classic triad is often absent 3.
- Lethargy and irritability are also common presenting signs, especially in infants 3.
- A rectal examination with testing for occult blood is an important part of the evaluation and is frequently positive 3.
- History of vomiting, abdominal pain, and rectal bleeding can be predictors of intussusception 5.
- Physical examination findings of abdominal mass, abdominal tenderness, and guiac positive stool can also be predictors of intussusception 5.
Imaging Features
- The imaging appearance of a bowel-within-bowel configuration with or without contained fat and mesenteric vessels is pathognomonic for intussusception 2.
- CT imaging can show evidence of loss of the layered pattern, accumulation of extraluminal fluid collection, and bowel perforation, which may suggest intestinal necrosis 2.
- Ultrasound can show the characteristic target sign or pseudokidney sign, which is diagnostic of intussusception 6.