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Flank pain and the diagnosis of acute renal colic is one of the most common and costly evaluations performed in the emergency department (ED) in the United States. The gold standard for diagnostic imaging of patients who present with flank pain remains non-contrast computed tomography (CT) due to its superior sensitivity and specificity for the identification of urolithiasis when compared to other imaging modalities. Due to concerns regarding radiation exposure, cost, and incidental findings, the relative benefits of alternative imaging modalities for the assessment of suspected renal colic have been evaluated. Ultrasound (US) in particular has been shown to be a safe alternative approach in this clinical scenario. Ultrasound, however, has limitations in defining specific anatomic and stone information needed by urologists to guide clinical management.

An US-first, delayed CT approach for the evaluation of patients with suspected renal colic is both feasible and safe. ¾ of enrolled patients received US alone with no missed alternative diagnoses or complications. Nearly 40% of subjects definitively passed a stone and only 10% required surgical intervention. Avoiding upfront CT imaging should be strongly considered in this patient population. The need for confirmatory imaging or clinical follow-up to ensure stone passage remains a question that will require further study and additional long-term data.

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Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.