Over the last two decades, the utilization of CT scan for nephrolithiasis has increased nearly 10 fold without an increase in diagnosis, stone complications or hospitalization rates. Recently clinical decision rule to determine which patients require CT imaging to exclude serious alternative diagnoses was published. Additionally, another recent study compared outcomes in patients with suspected renal colic randomized to either ultrasound or renal CT and found no difference in outcomes, but increased radiation exposure, length of stay, and cost with CT. In this case based interactive discussion the speaker will discuss the historical evidence behind increased CT use, the latest research, and a commonsense approach to the workup of renal colic.