Contrast-Enhanced Voiding Urosonography (ceVUS) for VUR in Children
Contrast-enhanced voiding urosonography (ceVUS) utilizes microbubble ultrasound contrast agents administered intravesically through a urethral catheter for sonographic evaluation of vesicoureteral reflux (VUR) in children. The method enables diagnosis, grading, and monitoring of VUR, as well as assessment of urethral anatomy.
Principle of the Method
The same microbubble contrast agents used in other CEUS applications (e.g., SonoVue/Lumason, approved for intravesical use in children) are employed; however, in ceVUS they are administered intravesically via urinary catheter rather than intravenously. Following bladder filling, sonographic assessment of contrast reflux into the ureters and pyelocalyceal system is performed in real time, including during micturition.
Reflux Grading
Reflux on ceVUS is graded using a 5-point scale analogous to voiding cystourethrography (VCUG): ranging from Grade I (contrast in ureter only) to Grade V (severe dilation and tortuosity of ureter with loss of fornices). Due to real-time visualization, ceVUS is superior to VCUG in detecting intrarenal reflux.
Diagnostic Value and Safety
Prospective safety assessment of intravesical administration of second-generation contrast agent was performed in children (Papadopoulou F. et al., Pediatr Radiol 2014;44:719–728). Comparative studies of 2D, static 3D, and real-time (4D) ceVUS with VCUG in children with VUR confirmed the applicability of the method (Woźniak MM. et al., Eur J Radiol 2016;85:1238–1245). ceVUS is comparable to, and in several aspects superior to, VCUG and radionuclide cystography in detection and grading of reflux.
Clinical Significance
The absence of radiation exposure makes ceVUS the preferred method for surveillance of children with VUR requiring repeated studies and reduces stress for the child and parents. Indications and technique are outlined in the ESPR Uroradiology Task Force / ESUR Paediatric Working Group recommendations and in the EFSUMB position statement on CEUS application in pediatrics.
Frequently asked questions
How is contrast administered in ceVUS?
Microbubble ultrasound contrast agent is administered intravesically through a urethral catheter, followed by sonographic assessment of reflux in real time, including during micturition.
How is reflux graded in ceVUS?
Using a 5-point scale analogous to voiding cystourethrography: from Grade I (contrast in ureter only) to Grade V (severe dilation and tortuosity with loss of fornices).
Has the safety of this method been studied in children?
Yes, prospective safety assessment of intravesical administration of second-generation contrast agent was conducted in children (Papadopoulou F. et al., Pediatr Radiol 2014); the method does not use ionizing radiation.
What can be assessed with ceVUS besides VUR?
In addition to VUR diagnosis and monitoring, the method allows evaluation of urethral anatomy and is superior to VCUG in detecting intrarenal reflux.
What are the advantages of ceVUS over radiological methods?
The method eliminates radiation exposure, which is important for repeated studies in children, and reduces stress for the child and parents.