Muhammet Fırat ÖZTEPE, Ali Osman GÜLMEZ
Advanced Radiology and Imaging - 2026;3(2):44-49
Objectives: To evaluate the relationship between stone size, stone location, and the presence and severity of hydronephrosis in patients with a single unilateral ureteral stone identified on non-contrast computed tomography (CT). Methods: In this retrospective single-center study, adult patients with a single, unilateral ureteral stone detected on non-contrast CT examinations of the urinary tract performed between February 7, 2022, and April 13, 2026, were included. Stone size, location, hydronephrosis status and grade, and accompanying imaging findings were recorded. Associations between stone characteristics and hydronephrosis severity were assessed using correlation analyses, chi-square tests, and regression models. Receiver operating characteristic (ROC) analysis was performed to evaluate the ability of stone size to predict moderate-to-severe hydronephrosis. Results: A total of 128 patients were included. The median age was 45 years; 77.3% were male. Hydronephrosis was present in 116 patients (90.6%), while 58 patients (45.3%) had moderate-to-severe hydronephrosis. Stone size increased significantly with greater hydronephrosis severity (rho=0.422, p<0.001). In multivariable ordinal logistic regression analysis, each 1-mm increase in stone size was independently associated with a higher hydronephrosis grade [odds ratio (OR): 1.20, 95% confidence interval (CI): 1.07-1.33, p=0.001]. Proximal or mid-ureteral stones were also independently associated with greater hydronephrosis severity compared with distal/ureterovesical junction stones (OR: 2.40, 95% CI: 1.14-5.07, p=0.022). The area under the curve for predicting moderate-to-severe hydronephrosis was 0.747. Conclusion: Increasing stone size is independently associated with greater hydronephrosis severity in patients with a single unilateral ureteral stone. Proximal or mid-ureteral stone locations are also associated with more advanced hydronephrosis. These findings suggest that stone characteristics may provide valuable information regarding the severity of urinary tract obstruction.
