Abstract

Objective: This study aimed to distinguish between obstructive and non-obstructive dilation of the upper urinary tract using ureterovesical jet flow analysis with Doppler ultrasonography (US) and manual flank compression.

Materials and methods: The study enrolled 54 patients (11 women, 43 men; mean age 27.5 years) with unilateral hydronephrosis. All but 2 pregnant patients underwent the Doppler US and the reference standard test [intravenous pyelogram (IVP)]  after standardized hydration. The distended urinary bladder was visualized in the transverse plane to evaluate both ureteral orifices simultaneously. During and after compression of each flank, the jet flows were recorded in Doppler mode. The jet flows were quantified by calculating the longitudinal extent of the color spread into the bladder on both sides. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the test for determining the degree of obstruction were evaluated statistically.

Results: Ureterovesical jet flow could not be visualized with flank compression in 4 cases. Three of these cases had complete obstruction on IVP. In the 22 cases that had markedly reduced flow compared to the contralateral side on Doppler US, the IVP showed similar stasis. In the 19 cases that had mildly diminished flow compared to the contralateral side on Doppler US, no significant difference was detected in the pyelogram and nephrogram phases on IVP.

Conclusion: Doppler examination of the ureterovesical jet flows during flank compression may be a good diagnostic method for evaluating the degree of obstruction, especially in patients in whom magnetic resonance imaging or computerized tomography is contraindicated.