Imaging Possible Appendicitis With CT

Pain in the right lower abdomen is one of the commonest reasons patients present to general surgeons as an emergency. Whether or not such patients have appendicitis is crucial to their assessment. In UK practice, when the diagnosis is unclear, ultrasound scanning (US) is commonly used to investigate the problem. US is very safe but it will only visualise the appendix in the minority of cases. As a result, the sensitivity for diagnosing appendicitis in this setting is probably only 5-30%. Alternatively, computed tomography (CT) is an accurate way of diagnosing appendicitis in over 90% of cases. CT scans are readily available and with modern scanners, high quality images can be achieved with lower radiation doses. Unenhanced scanning avoids the use of contrast media and permits further reductions in ionising radiation exposure.

Inclusion criteria

• Acute presentation with abdominal pain and/or tenderness which is most marked in the right lower abdomen

Exclusion criteria

• Age<18
• Age>60
• Pregnancy
• Patients with a firm clinical diagnosis of appendicitis where surgical management is indicated at presentation
• Patients who have undergone CT scanning within the past two months
• Patients with cognitive impairment who would lack capacity to give consent
• Inability to understand written or spoken English
• Patients who have previously undergone appendicectomy