Objective: The purpose of this study was to evaluate the incidence of nonobstructing renal stones on unenhanced CT in patients presenting to the emergency department with renal colic and to determine whether this finding might be the cause of patients' symptoms.
Conclusion: Nonobstructing renal stones on unenhanced CT are a frequent finding in patients evaluated in the emergency department for suspected renal colic. These stones are usually not recognized as the cause of pain by physicians and may be responsible for multiple clinical and radiologic evaluations. In the absence of other clinical or CT evidence of a separate cause, these stones are likely to be the cause of a patient's acute pain.