Vesico-ureteral reflux: diagnosis and staging with voiding color Doppler US: preliminary experience

The aim of this study is to assess the accuracy of a new US examination: 'voiding color Doppler US ' in the early diagnosis and staging of vesico-ureteral reflux (VUR). The contrast agent US was SH U 508A (Levovist, Schering, Berlin), which produces a chromatic accentuation of the signals picked up by the color Doppler US. Eighteen patients (10 females, eight males) were recruited for the study. In two patients a second examination was performed for follow-up after a VUR conservative therapy. All patients were taken under examination for the evaluation of possible VUR. In all patients the voiding color Doppler US was followed by voiding cystourethrography (VCUG) and the data obtained were compared.

A total of 18 patients aged between 3 months and 10 years, were recruited for the study. The results of the examination were the following: urinary tract infections, follow-up of VUR after conservative or surgical therapy, miscellaneous indications. Voiding color Doppler US was performed, followed by a VCUG. The voiding color Doppler US consists in the trans-catheter introduction of a contrast agent SHU 508 A (Levovist, Schering, Ag. Berlin) into the bladder and a subsequent test with the color Doppler US to show or exclude the presence of reflux into the ureters and/or into the pyelo-caliceal cavity of the kidneys. After the introduction of the contrast agent US the ultrasound scanning of the bladder, the ureters and the pyelo-caliceal cavity was performed to examine the reflux degree. The ultrasonographic investigations were perfomed with AU 590 asyncronus US (Esaote Biomedica, Genova) with a 3.5 MHz convex probe.

After the trans-catheter introduction of the contrast agent US, vesico-ureteral reflux occured in 13 patients (77.2%). The reflux degree was also measured by means of ultrasound and was later confirmed by VCUG. The mean times of each examination were as follows: initial US, 10 min; catheterization, 8 min; voiding color Doppler US, 15 min; overall VCURG examination 10 min. The overall mean duration of the voiding color Doppler US examination was 33 min. The comparable mean time for VCUG, including the catheterization time, was 20 min. No reactions of intolerance to the ultrasound contrast agent occurred.

The voiding color Doppler US test has evidenced in all patients the presence of the contrast agent US in the bladder after the introduction. In 13 patients (77.2%) with presence of VUR, the voiding color Doppler US test has established the reflux degree confirmed by cystourethrography. The superimposability of the data obtained with voiding color Doppler US and VCUG would seem to confirm the importance of this new ultrasonographic technique in the diagnosis and staging of VUR.