Do not perform computerized tomography (CT) for the diagnosis of renal stones. It is initially preferable to use ultrasound.

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The presence of renal stones can be identified by a simple ultrasound test. Ultrasonography identifies calcium stones particularly well, but also reveals stones of other compositions, with the exception of certain particular types (e.g. cysteine stones). Sometimes ultrasound can even show the consequences of the presence of stones (ureteral dilation or even obstruction, with an increase in its diameter, upstream from where the stone is located). Ultrasound is inexpensive and avoids exposing patients to a certain amount of radiation. CT is useful when a stone’s shape or position warrants its removal (surgically or endoscopically, or with the aid of shock waves).


1. Techniques for Minimizing Radiation Exposure During Evaluation, Surgical Treatment, and Follow- up of Urinary Lithiasis. Javier L. Arenas, D. Duane Baldwin. Acad Emerg Med. 2011 Jul; 18(7): 699-707.
2. Radiological imaging of patients with suspected urinary tract stones: national trends, diagnoses, and predictors. Westphalen AC, Hsia RY, Maselli JH, Wang R, Gonzales R. Radiology 2003 Aug; 228(2): 319-29.
3. Evaluation of the patient with flank pain and possible ureteral calculus. Tamm EP, Silverman PM, Shuman WP. Radiology 2003 Aug; 228(2): 319-29.
4. Ultrasonography versus computed tomography for suspected nephrolithiasis. 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. N Engl J Med 2014 Sep 18; 371(12): 1100-10.

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