Normal Renal Ultrasound Might Obviate Need for Computed Tomography in Suspected Urolithiasis

Patients with symptoms consistent with renal colic commonly undergo computed tomography (CT) urography, but are the costs, radiation exposure, and negative effects on emergency department (ED) throughput necessary? To determine whether renal ultrasound can identify patients who are unlikely to need urologic intervention, investigators retrospectively reviewed medical records for 817 consecutive adults who underwent renal ultrasound for suspected urolithiasis at two academic EDs in Ontario, Canada, during 1 year.

Ultrasound scans were normal in 43% of cases, suggested ureterolithiasis in 22%, showed stones in 29%, and showed disease unrelated to urolithiasis in 6%. In 27 patients who had stones visualized on both initial ultrasound and subseq…