[Stress sonography of the lower urinary tract]

Mild caliectasis in patients with occult ureteropelvic obstruction can cause difficulties in the decision on operative or non-operative measures. In such situations diuresis renography, diuretic radionuclide urography and perfusion pressure flow studies (Whitaker test) can be very useful. Furosemide-sonography is a new, non-invasive method demonstrating functional subpelvic obstruction. Standardised conditions before and after application of furosemide are necessary. This new diagnostic method is demonstrated based on a evaluation in 22 patients presenting radiological evidence of minor ureteropelvic obstruction.