Limited sensitivity and size over measurements of ultrasound affect medical decisions for ureteral stone compared to non-contrasted computed tomography

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.