Imaging Recommendation for Suspected Abdominal Hernia
For adults with suspected abdominal wall hernia, ultrasound is the recommended initial imaging modality when clinical examination is equivocal, while CT is reserved for internal hernias or when complications are suspected. 1, 2
Initial Imaging Strategy by Clinical Scenario
External/Abdominal Wall Hernias in Adults
Ultrasound should be obtained first when physical examination is inconclusive—specifically when patients present with abdominal pain without a palpable hernia or when a palpable mass is of questionable etiology 1, 2
Ultrasound is accurate, non-invasive, relatively inexpensive, and readily available for evaluating abdominal wall hernias 1
In a series of 144 patients with pain alone and no palpable hernia, ultrasound identified occult hernias in 21 patients (15%) who required surgery, while 108 with negative ultrasound were successfully managed conservatively 1
Ultrasound is particularly valuable for groin hernia assessment in adults and is the imaging modality of choice for all pediatric abdominal wall hernias 2
Internal Hernias or Complicated Presentations
CT abdomen/pelvis with IV contrast is the imaging modality of choice when internal hernia is suspected or when complications such as bowel obstruction, incarceration, or strangulation are concerns 2, 3
CT provides rapid acquisition, multiplanar reconstruction capability, excellent spatial resolution, and superior sensitivity for detecting complications 2
CT can demonstrate the anatomic location of the hernia, identify hernial contents (fatty tissue, bowel, other organs, or fluid), and detect complications including neoplasms or inflammatory conditions within the hernial sac 4, 5
Special Diagnostic Considerations
When Ultrasound is Equivocal
MRI is beneficial when symptoms could be attributable to either a hernia or a musculoskeletal source, helping differentiate between these etiologies 2
Fluoroscopic herniography is a sensitive investigation for patients with groin pain and suspected hernia when physical examination cannot identify a hernia 2
Internal Hernia Red Flags on Imaging
Look for closed-loop small-bowel obstruction patterns and abnormally located bowel loops relative to normally positioned small bowel or colon—these findings should prompt immediate assessment for internal hernia 2
Internal hernias are challenging both clinically and radiologically, requiring high index of suspicion 2
Common Pitfalls to Avoid
Do not rely solely on plain radiographs or barium studies—while historically used, these modalities have been largely superseded by cross-sectional imaging for hernia diagnosis 3, 4
Ultrasound is operator-dependent; negative ultrasound in a patient with high clinical suspicion warrants either repeat examination by an experienced operator or progression to CT 1
In obese patients, those with abdominal wall scarring, or patients with significant pain, clinical diagnosis is particularly difficult and imaging should be obtained early rather than relying on physical examination alone 5
CT findings may be subtle or confusing, particularly for internal hernias; familiarity with the broad range of imaging appearances is essential for accurate diagnosis 3
Post-Operative Hernia Assessment
Ultrasound is valuable for evaluating patients with early or late post-herniorrhaphy complaints, including those with inordinate pain or excessive swelling in the early post-operative period 1
Ultrasound can confirm clinical findings or alter the diagnosis, changing the treatment plan from surgical to conservative management or vice versa 1