Three-dimensional ultrasonography-based virtual cystoscopy of the pediatric urinary bladder - A preliminary report on feasibility and potential value

Objective. The purpose of this study was to validate the feasibility and potential of 3-dimensional ultrasonography (3DUS)-based virtual cystoscopy in the pediatric urinary bladder. Methods. Twenty patients (age range, newborn-14 years) underwent urinary tract ultrasonography and 3DUS of the urinary bladder. From this data set, virtual cystoscopy was reconstructed for visualization of the inner bladder surface. Three-dimensional ultrasonography was compared with 2-dimensional ultrasonographic (2DUS) findings, voiding cystourethrography (VCUG) results, and reports from cystoscopy or surgery when available. Results. Three-dimensional ultrasonography was feasible in all patients. Data quality was sufficient for virtual cystoscopy without major motion artifacts. The 3DUS results matched all other findings, particularly, 3DUS superiorly visualized the ureteral ostium and the bladder neck configuration; in 5 patients, 3DUS depicted pathologically shaped ostia not detected by 2DUS. This correlated with the presence of vesicoureteral reflux on VCUG. Performing virtual cystoscopy added 1 minute to the investigation time (range, 0.5-2 minutes) and 3 minutes for postprocessing and viewing (range, 2-5 minutes), Conclusions. Three-dimensional ultrasonography-based virtual cystoscopy is feasible in the pediatric urinary bladder without sedation. It reveals surface information not accessible by 2DUS, improving detection of pathologic conditions such as atypically shaped ureteral ostia. Three-dimensional ultrasonography-based cystoscopy may become a valuable adjunct to 2DUS of the pediatric urinary tract, improving selection criteria for further imaging such as VCUG, and potentially may help reduce the need for endoscopic cystoscopy. However, these preliminary results still have to be confirmed in prospective studies with larger patient numbers.