Novel use of contrast enhanced ultrasonography with urodynamics in children: A comparison study to fluoroscopy

Video urodynamics (UDS) has classically been performed using fluoroscopy (fluoro). Contrast enhanced voiding ultrasonography (ceVUS) has rarely been reported for use with UDS. This is the first study to compare the imaging characteristics of ceVUS versus fluoro UDS.

Children were enrolled for ceVUS UDS who previously underwent fluoro UDS. Demographics, imaging data for ceVUS and fluoro UDS, time between studies, and clinical data between studies were recorded. Changes in clinical status included implantation/cessation of catheterization or anticholinergic medications, leakage between, urinary tract infections, hydronephrosis and neurologic changes. Comparison testing was performed using McNemar's Chi-Squared and Wilcoxon matched-pairs signed rank test.

Seventy-five children were recruited. Median time between studies was 1.3 years (IQR 0.9-2.9). There were no differences for bladder shape (p = 0.59), vesicoureteral reflux (p = 0.10), bladder neck (p = 0.59) or urethra (p = 1.0) between studies. In 5 cases, the bladder neck could not be visualized adequately due to layering of the microbubble contrast against urine. Benefits to ceVUS included ability to visualize the exact moment the bladder neck opened. Following exclusion of patients with clinical changes that might affect imaging findings, an analysis of 28 patients demonstrated no differences between the two studies.

CeVUS can be used adequately in conjunction with UDS. Limitations to ceVUS include more granular imaging for bladder shape versus fluoro and inability to visualize bladder neck if residual urine is in the bladder, mitigated by bladder emptying. Benefits include ability to visualize the dynamic activity of the bladder neck due to constant imaging with ceVUS.