ceVUS for VUR in Children Instead of Cystography: ESPR 2024

Clinical Response: What to Use Instead of VCUG

For a child who needs to confirm or exclude vesicoureteral reflux (VUR) without radiation exposure, the alternative to voiding cystourethrography is contrast-enhanced voiding urosonography, ceVUS. In the ESPR Urogenital Task Force 2024 document, it is formulated as the preferred non-radiative method for assessing VUR and the urethra. Practically, this means: in a typical request after a urinary tract infection, when monitoring known VUR, or after endoscopic/surgical treatment, ceVUS should be considered first if the method is available and a trained team is present.

An important limitation: ceVUS is not an “ultrasound of the kidneys with intravenous contrast.” The contrast is introduced intravesically via a catheter, and the study is conducted during the bladder filling phase and during urination. The diagnostic task is to see microbubbles of the contrast agent in the ureter, pelvis, and calyces, and to assess the passage of urine through the urethra.

What the ESPR 2024 Update Changed

The ESPR update is dedicated to the modern role of methods traditionally grouped around voiding cystourethrography. The main practical shift is the move away from automatically choosing X-ray VCUG as the standard first test where only diagnosis or monitoring of VUR is required. ceVUS is considered a method that allows obtaining a key answer without ionizing radiation.

The consensus also emphasizes that the urethra should be assessed as part of the study. This is important because the previous argument for VCUG often was: “Ultrasound will show reflux, but not the urethra.” Modern ceVUS includes targeted visualization of the urethra during voiding, usually transabdominally and/or transperineally, using contrast-specific modes.

Indications Where ceVUS is Particularly Appropriate

• primary diagnosis of VUR in a child when cystographic assessment is required by the clinical scenario;
• dynamic monitoring of known VUR;
• follow-up after endoscopic treatment of VUR or surgical correction;
• assessment of contralateral reflux in unilateral processes;
• situations where it is particularly important to avoid cumulative radiation exposure, such as in repeated studies.

The method does not negate clinical selection. The decision on cystographic examination is made jointly with a pediatrician, nephrologist, or urologist, taking into account urinary tract infection, ultrasound data of the kidneys and bladder, kidney function, and treatment plan. ceVUS specifically answers the cystographic question but does not replace a complete ultrasound of the kidneys, ureters, and bladder.

How the Study is Conducted

1. First, a baseline ultrasound is performed: kidneys, pelvicalyceal system, ureters if visualized, bladder, residual urine as indicated.
2. The bladder is filled through a urethral catheter with a sterile solution containing an ultrasound contrast agent.
3. During filling, both ureteral orifices, retrovesical segments, ureters, pelvis, and calyces are continuously or serially assessed.
4. Upon the appearance of contrast microbubbles above the bladder, the side, phase of occurrence, and degree of VUR are recorded.
5. During urination, the urethra is assessed, and reflux is rechecked, as it may only manifest during voiding in some children.

The quality of the study depends on technique: adequate filling, calm environment, appropriate contrast-specific mode, documentation of both kidneys and urethra. It is important to indicate in the protocol whether the voiding phase was achieved; without it, the assessment of the urethra and some refluxes may be incomplete.

Classification of VUR in ceVUS

ESPR uses a 5-grade assessment of VUR, comparable to the familiar international grading in cystography. The conclusion should indicate the degree separately for each side and, if possible, the phase of detection: filling, voiding, or both phases.

What to Include in the Protocol

The ceVUS protocol should be no shorter than a radiological conclusion for VCUG. The minimum data set: type of study, method of contrast administration, quality of bladder filling, achievement of voiding, presence or absence of VUR on the right and left, grade I–V, phase of appearance, condition of the urethra, and significant limitations.

The phrase “VUR not detected” is correct only with adequate filling and completed voiding phase or with a clear indication that voiding was not assessed. If the child did not urinate during the study, this should be directly reflected: the diagnostic value for the urethra and for reflux occurring only during urination is limited.

When VCUG is Still Needed

Despite the priority of ceVUS, VCUG does not disappear from practice. The X-ray method may be required if it is expected that specific radiographic anatomical detailing will change the strategy: complex congenital pathology of the lower urinary tract, ambiguous urethral assessment in ceVUS, need to document anatomy before a specific intervention, or local conditions where quality ceVUS is unavailable.

In other words, VCUG becomes not a “default study” but a selective test. This approach is especially important for children with recurrent examinations, as ceVUS does not carry ionizing radiation.

Advantages and Limitations of ceVUS

• Advantage: absence of radiation exposure while maintaining the cystographic logic of the study.
• Advantage: high suitability for repeated monitoring and treatment control.
• Advantage: simultaneous assessment of kidneys, bladder, reflux, and urethra in one visit.
• Limitation: the method is operator-dependent and requires experience in pediatric contrast ultrasound diagnostics.
• Limitation: like VCUG, requires bladder catheterization.
• Limitation: incomplete voiding reduces the value of the study for the urethra and may miss reflux that manifests only during urination.

Practical Algorithm for the Physician

If a child has a justified indication for cystographic assessment of VUR, the first question should not be “VCUG or nothing,” but “is quality ceVUS available.” If the method is available and there is no specific need for radiographic anatomy, preference should be given to ceVUS. When referring, it is important to write the clinical task: primary diagnosis of VUR, monitoring of known VUR, postoperative control, suspicion of urethral pathology.

The optimal conclusion for the clinician answers 3 questions: is there VUR, what is its grade on the I–V scale on each side, and was the urethra assessed during voiding. These points allow replacing VCUG in most typical scenarios, maintaining diagnostic value and eliminating radiation exposure.