28th May 2025

A 38-year-old woman presents to A&E with a 4-day history of intermittent abdominal pain, which has escalated to become constant over the past day.

A 38-year-old woman presents to A&E with a 4-day history of intermittent abdominal pain, which has escalated to become constant over the past day. Her observations show a low grade fever and tachycardia, and on examination she is very tender in the right upper quadrant, especially on deep inspiration.

Which of the following is the most important diagnostic investigation for the most likely diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.