Ultrasound for pediatric appendicitis

  • Patient preparation: none
  • Contrast used: none
  • Technique: linear transducer, perform a graded compression examination in transverse and sagittal planes along the ascending colon from the hepatic flexure to the cecum focusing in the right lower quadrant near the junction of the terminal ileum and cecum and where the iliac vessels cross the psoas muscle, graded compression done slowly without sudden release to optimize patient tolerance and prevent rebound tenderness, graded compression used to displace overlying bowel gas and decrease distance between transducer and appendix, if appendix cannot be found look in retrocecal region
  • Images to obtain: transverse and sagittal grayscale images of the appendix
  • Looking for:
    — Criteria for acute appendicitis – non-compressible and non-peristalsing blind ending tubular structure with a diameter > 8 mm in diameter, if 6-8 mm in diameter is equivocal for acute appendicitis, if < 6 mm in diameter is normal appendix
    — Periappendiceal fluid and inflammation
    — Abscess for evidence of perforated appendicitis
  • Post procedure tasks: if exam is negative and patient is female consider performing pelvic ultrasound to look for ovarian pathology as source of pain