Cystosonography with echocontrast: a new imaging modality to detect vesicoureteric reflux in children

Abstract

Background: Conventionally, vesicoureteric reflux (VUR) is assessed by fluoroscopic micturating cystourethrography (MCU) or direct or indirect radionuclide cystography (RNC). There is preliminary experience with contrast-enhanced sonography for the detection of VUR.

Objective: To evaluate the usefulness of contrast-enhanced ultrasonography using galactose suspension as an echogenic contrast medium.

Materials and methods: In this study a galactose suspension was instilled into the bladder in 58 neonates, infants and children along with normal saline to detect the presence and the severity of VUR through the enhanced US signal. The results were compared with those of MCU and RNC. One ml/kg of echocontrast in the neonatal age group, and 0.5 ml/kg thereafter, were slowly instilled through a 4-F catheter after preliminary supine and prone urinary tract US. Indications for the investigation were antenatally diagnosed pyelectasis (21 cases) and pyelonephritis (37 cases). In 38 patients echocontrast cystosonography (ECS) was performed before, and in 20 patients after, MCU or RNC.

Results: ECS detected 76 refluxing units in 50 patients. In eight patients, no VUR was shown, and none of these developed a urinary tract infection in 18 months of follow-up. In 43 patients, MCU or RNC detected 62 refluxing units, while in 15 no VUR was shown. Taking MCU as the gold standard and using the same grading scale, the sensitivity of ECS was 100 %. No side effects were observed. Several urinary tract abnormalities were detected by ECS. The male urethra was studied by ECS, both by retrograde infusion and during micturition.

Conclusions: ECS is a promising imaging technique for detecting and grading VUR without exposing patients to ionising radiation.