Current status of vesicoureteral reflux diagnosis.

In children, diagnostic imaging for vesicoureteral reflux (VUR) encompasses both radiologic and sonographic modalities. The former comprises voiding cystourethrography (VCUG), the most widespread method for examination for reflux, and radionuclide cystography (RNC). In RNC the radiation exposure is significantly less than in VCUG with continuous fluoroscopy, but the anatomic details depicted are much inferior. With the introduction of pulsed fluoroscopy, the radiation exposure of VCUG has been markedly curtailed. VCUG is the first imaging choice for the urethra. The sonographic diagnosis of VUR with the intravesical administration of an ultrasound (US) contrast agent-voiding urosonography (VUS)-is being used increasingly in the routine diagnostic imaging work-up of reflux. Various sonographic reflux examination methods had been tried in the past. The real breakthrough came with the availability of stabilized US contrast media. Further impetus came with the introduction of harmonic US imaging. The recent release of a second generation US contrast medium promises to make a further positive impact on VUS. The diagnostic accuracy of contrast-enhanced VUS has been found to be comparable to radiologic methods. VUS is primarily performed in follow-up studies and as the primary reflux examination modality in girls.