Can real-time ultrasonography replace static B-scanning in the diagnosis of renal obstruction?

Two hundred consecutive patients were evaluated for renal obstruction using both static B-scanning and high resolution real-time scanning. The overall diagnostic accuracy was 93% for the static B-scanner and 94% for the real-time unit, with a false positive diagnostic rate of 8% for each. Because of its greater flexibility and shorter scanning time, real-time can replace static B-scanning in the diagnosis of renal obstruction. It has also become the preferred method of guidance for interventional uroradiological procedures. The pitfalls of real-time scanning in evaluating renal obstruction are also discussed.