Category: Pediatrics
Posted: 4/26/2013 by Mimi Lu, MD
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An overweight 5 year old male presents with acute onset abdominal pain that localizes to the right lower quadrant. What are some causes of a limited or nondiagnostic ultrasound study in children?
Acute appendicitis is a time sensitive diagnosis. Ultrasound is frequently used as the initial diagnostic imaging in children. There are several reasons why the appendix may not be visualized, including retro-cecal location, normal appendix, perforation, and inflammation around the distal tip. An additional clinical predictor associated with poor or inconclusive ultrasound results in appendicitis is increased BMI (body mass index).
A study examining 263 pediatric patients found when BMI > 85th percentile and clinical probability of appendicitis was <50%, 58% of ultrasounds were nondiagnostic. Children with a BMI <85th percentile and clinical probability of appendicitis was <50%, had nondiagonstic scans 42% of the time. These trends were also mimicked in the patients with a higher clinical probability of appendicitis. In the child with a nondiagnostic ultrasound, options include observation and repeat ultrasound scan or CT scan, both of which have associated risks.