Comparison of the Diagnostic Performance of Two-Dimensional Ultrasound and Colour Doppler Ultrasound and Associated Sonographic Features in Ureteral Stones of Different Diameters.

OBJECTIVE: This study aimed to compare the diagnostic performance of two-dimensional ultrasound (2D-US) and colour Doppler flow imaging (CDFI) for ureteral stones of different diameters, and to analyse CDFI-associated sonographic features. METHODS: A retrospective analysis was conducted on the clinical data of 150 patients with suspected ureteral stones who were admitted to the urology department of our hospital between January 2022 and December 2025. All patients underwent both 2D-US and CDFI examination, with non-contrast computed tomography (NCCT) as the gold standard. The overall diagnostic performance of the two ultrasound modalities was compared, including the detection rate and CDFI-associated sonographic features of stones of different diameters. In addition, the correlation between stone diameter, twinkling artifact intensity, and ureteral jet abnormalities were analysed. RESULTS: Among 150 suspected patients, 104 were diagnosed with ureteral stones by NCCT, and 46 were negative. The 104 stone-positive patients were classified into small-diameter (<6 mm), medium-diameter (6-8 mm), and large-diameter (>8 mm) stone groups. CDFI improved paired diagnostic accuracy by 14.0 percentage points (95% confidence interval, 6.6-21.4; exact McNemar p < 0.001). Detection rate of CDFI was higher for stones <6 mm (95.83% vs 62.50%, p = 0.008) and 6-8 mm (87.88% vs 72.73%, p = 0.002), whereas no difference was observed for stones >8 mm (92.86% vs 100.00%, p = 1.000). Twinkling artifact intensity (H = 12.428, p = 0.002) and ureteral jet abnormalities (H = 9.877, p = 0.007) differed among the three stone-diameter groups. Maximum stone diameter correlated positively with twinkling artifact intensity (Spearman r = 0.582, p < 0.001) and ureteral jet abnormalities (r = 0.543, p < 0.001). CONCLUSIONS: CDFI has advantages over 2D-US in diagnosing ureteral stones, especially for small-diameter stones. Twinkling artifact intensity and abnormal ureteral jet signals at the ureteral orifice are closely associated with stone diameter and can serve as important auxiliary indicators for diagnosing ureteral stones of different diameters.