Non-invasive vesicoureteral reflux imaging

Abstract

Objective: To evaluate non-invasive and non-ionizing methods of determining the presence of vesicoureteral reflux (VUR) and to preview upcoming ideas that have the potential of finding VUR non-invasively.

Materials and methods: We performed a PubMed search using the terms 'vesicoureteral reflux/radiography', 'vesicoureteral reflux/ultrasonography' and 'magnetic resonance imaging/urologic disease'. We also included information from a recent American Academy of Pediatrics meeting and our own research.

Results: Voiding ultrasonography is non-radiating and has undergone significant improvements recently. Best results require instillation of contrast through invasive catheter placement, and doubts regarding sensitivity and specificity are significant. Magnetic resonance cystograms are best with catheter-instilled contrast. They are expensive, require anesthesia or sedation, and are impractical. Horizon technologies include magnetic resonance cystogram with gadolinium 'activation' within the bladder. Another promising completely non-invasive method includes warming the bladder with microwaves and measuring kidney temperatures before and after warming. Detection of a rise in kidney temperatures would indicate VUR.

Conclusions: Voiding cystourethrography remains the gold standard in reflux diagnosis but is invasive and submits the child to ionizing radiation. Developing technologies need improvements and further research before they may have a role in significantly decreasing voiding cystourethrography use or replacing it completely.