Purpose: To evaluate the limited sensitivity and size over measurements of ultrasound (US) for ureteral stone, and demonstrate how this influenced medical decisions.
Patients and methods: Retrospectively, we analyzed the data of patients with ureterolithiasis estimated by US and non-contrasted computed tomography (NCCT) within 48 h at our institution from January 1st 2014 to June 1st 2017. Stone size was grouped by the longest axis diameter on NCCT: < 5, 5-10, and > 10 mm. Then, US and NCCT results were compared for the sensitivity and measurements.
Results: A total of 614 cases of ureterolithiasis were visible on NCCT. The sensitivity of US for ureterolithiasis < 5, 5-10, and > 10 mm were 63.49, 79.06, and 84.67%, respectively (P = 0.001). US overestimated the size in 63.49 and 50.54% of patients with ureterolithiasis < 5 and 5-10 mm compared to NCCT, respectively (P < 0.001). Under the assumptions that patients with ureteral stone < 5, 5-10, and > 10 mm would be simply observed, received medical expulsive therapy (MET), and surgical interventions, 20.94 and 15.33% of patients with stone sized 5-10 and > 10 mm might be improperly observed due to negative US reports. Besides, 63.49 and 50.54% of cases with stone < 5 and 5-10 mm might receive more aggressive interventions ascribed to over measurements of US.
Conclusions: Limited sensitivity and size over measurements of US might significantly influence medical decisions for ureteral stone. Inaccurate evaluation of US should be taken in consideration for appropriate counseling options.
Keywords: Medical decisions; Non-contrast computed tomography; Over measurement; Ultrasound; Ureteral stone.