Clinical utility of abdominal and pelvic ultrasound in the evaluation of right iliac fossa pain in females.

BACKGROUND: Ultrasound (US) is often the imaging modality of choice in women with acute right iliac fossa (RIF) pain, identifying the appendix in up to 99% of patients. The literature, however, lacks clear guidelines on how ultrasonography should be performed to maximise sensitivity and specificity in such patients. Many centres perform untargeted abdomino-pelvic scans, including organs such as the liver and spleen, which unlikely contribute to the presenting complaint.

AIMS: We aimed to evaluate the clinical utility of unfocussed abdominal and pelvic US in women of reproductive age with acute RIF pain.

METHODS: This multicentre study describes 501 women between the ages of 12 and 50, over a 3-year period from three institutions, presenting acutely with RIF pain and investigated with US abdomen and pelvis.

RESULTS: 5.9% of cases confirmed appendicitis sonographically. A normal appendix was visualised in 0.2%. Over 10% identified gynaecological pathology, 41% relating to the right ovary. 10.4% incidental extra-pelvic findings were unrelated to the acute clinical presentation. 0.8% of patients had extra-pelvic findings meriting further clinical assessment.

CONCLUSION: The results herein reflect findings from high volume emergency surgical departments, demonstrating that unfocussed abdominal and pelvic ultrasounds are not an appropriate use of resources in reproductive women with RIF pain. Clinically relevant extra-pelvic US findings account for less than 1%, rarely contributing to the acute presentation. The appendix was only visualised in 6% of patients, suggesting that a focussed appendiceal and pelvic US would better assist diagnosis with a higher yield and increased sensitivity and specificity.