Australasian College for Emergency Medicine


Avoid requesting computed tomography (CT) imaging of kidneys, ureters and bladder (KUB) in otherwise healthy emergency department patients, age <50 years, with a known history of kidney stones, presenting with symptoms and signs consistent with uncomplicated renal colic.

Acute flank pain due to suspected renal colic is a common clinical presentation in the emergency department. While a CT-KUB allows a rapid, contrast-free diagnosis of kidney stones, it is a high ionizing-radiation technique. Younger patients with typical renal colic pain that remits spontaneously, or with analgesia, and have no features on history, examination or laboratory investigations that suggest complicated renal stones or a serious alternate diagnosis can be managed without repeated imaging. Concerning features include fever, features of urinary tract infection, lack of haematuria, ongoing high analgesia requirements, or palpable abdominal mass.

Supporting evidence
  • Moore CL, Bomann S, Daniels B, Luty S, Molinaro A, Singh D, Gross CP. Derivation and validation of a clinical prediction rule for uncomplicated ureteral stone—the STONE score: retrospective and prospective observational cohort studies. BMJ. 2014;348:g2191.
  • Katz SI, Saluja S, Brink JA, Forman HP. Radiation dose associated with unenhanced CT for suspected renal colic: impact of repetitive studies. Am J Roentolog. 2006;186(4):1120-4.
  • Patatas K, Panditaratne N, Wah TM, Weston MJ, Irving HC. 2012. Emergency department imaging protocol for suspected acute renal colic: re-evaluating our service. Emergency. 2014;85(1016).
  • Broder J, Bowen J, Lohr J, Babcock A, Yoon J. Cumulative CT exposures in emergency department patients evaluated for suspected renal colic. J Emerg Med. 2007;33(2):161-8.
  • Smith-Bindman R, Aubin C, Bailitz, J, Bengiamin, RN, Camargo CA Jr, Corbo J, Dean AJ, Goldstein RB, Griffey RT, Jay GD, Kang TL, Kriesel DR, Ma OJ, Mallin M, Manson, W, Melnikow J, Miglioretti DL, Miller, SK, Mills LD, Miner JR, Moghadassi M, Noble VE, Press GM, Stoller ML, Valencia VE, Wang J, Wang RC, Cummings SR. Ultrasonography versus computed tomography for suspected nephrolithiasis. N Engl J Med. 2014. 371:12.