What are the indications for ultrasound in the assessment of abdominal pain in adults?

In adult patients presenting with abdominal pain, ultrasound is indicated for several specific conditions:

• Suspected Renal or Ureteric Colic: Ultrasound should be offered as the initial imaging modality for suspected acute renal and ureteric colic ⁴,⁵. A low-dose non-contrast CT should only be considered if the diagnosis remains uncertain after ultrasound ⁴,⁵.
• Suspected Ectopic Pregnancy: For women in early pregnancy presenting with abdominal pain, transvaginal or transabdominal ultrasound is used to identify signs of a tubal ectopic pregnancy ². These signs include an adnexal mass (which may contain a gestational sac, yolk sac, or fetal pole), an empty gestational sac (tubal ring/bagel sign), a complex inhomogeneous adnexal mass, an empty uterus, or a collection of fluid within the uterine cavity (pseudo-sac) ². The scan also looks for moderate to large amounts of free fluid in the peritoneal cavity, which may indicate haemoperitoneum ².
• Evaluation of Abdominal Masses: An urgent direct access ultrasound scan (to be done within 2 weeks) should be considered for an upper abdominal mass consistent with an enlarged gall bladder or an enlarged liver ¹.
• Suspected Appendicitis: Ultrasound is the preferred imaging modality for pregnant women with suspected appendicitis ³. It may also be used in other adults when the diagnosis is uncertain to help reduce the negative appendectomy rate ³.