Diagnostic Accuracy of Ultrasonography Combined with the S.T.O.N.E. Criteria in Patients Suspected of Acute Ureteral Stone

Abstract

Background: Renal colic is a common emergency department presentation, typically evaluated by CT scan. This study assesses the diagnostic value of combining bedside ultrasound with the STONE score as a safer alternative for suspected ureteral stones. Methods: In this prospective study, 176 patients with renal colic symptoms were stratified by STONE scores into low-, moderate-, and high-risk groups. Bedside ultrasound findings were compared against CT results. Statistical analysis included sensitivity, specificity, and ROC curve evaluation. Findings: Ureteral stones were confirmed by CT in 101 patients (57.4). Hydronephrosis was present in 78.2 of stone-positive versus 17.3 of stone-negative patients. Ultrasound showed 75/89.2 (sensitivity/specificity) in low-risk, 74/56.3 in moderate-risk, and 83/42.9 in high-risk groups. The AUC was 0.78 for ultrasound alone versus 0.75 for the combined model. Conclusion: The ultrasound-STONE score combination reliably screens for ureteral stones in low/moderate-risk patients, potentially reducing unnecessary CT scans. CT remains preferred for high-risk cases due to ultrasound's limited specificity in this group. © 2026, Isfahan University of Medical Sciences(IUMS). All rights reserved.