Effectiveness of direct and indirect radionuclide cystography in detecting vesicoureteral reflux.

A modification of the direct radionuclide cystography technique to include filling, voiding, and postvoiding phases of the examination permitted a simulated comparison between direct and indirect radionuclide cystography. One hundred thirty-seven examples of reflux were documented with this technique. Of these, 96 instances of reflux (70%) were recorded during two or more phases and thus would have been detected by either technique. Twenty-nine examples (21%) were only detected during filling and thus would have been missed by the indirect radionuclide technique and by some roentgenographic techniques. Only 12 examples (9%) were detected during the voiding phases only. The modified direct method of radionuclide cystography, which continuously monitors the urinary tracts during filling, voiding, and postvoiding, is offered as the best current technique for assessing vesicoureteral reflux.