Urological examinations —
Micturating cystourethrography (MCU)
Micturating cystourethrography (MCU) is a central examination in pediatric urology, which is used in particular to diagnose vesicoureteral reflux (VUR). With VUR, urine flows from the bladder back into the ureters, which can lead to recurrent infections and potential damage to the kidneys. The MCU also helps to identify infravesical obstructions and complex urogenital malformations.
Conventional MCU enables not only vesicoureteral reflux to be diagnosed, but also provides detailed assessment of the morphology of the ureters and bladder (e.g. bladder wall contour, trabeculations, diverticula, ureter morphology). The MCU also allows the assessment of urethral morphology including strictures, valves, diverticula and fistulae, as well as the bladder filling volume and residual urine.
In MCU, a contrast agent is introduced into the bladder either by catheterization or by suprapubic puncture. During bladder filling and micturition (emptying of the bladder), fluoroscopy is performed to determine whether there is reflux, i.e. backflow of urine towards the kidneys. The reflux can be graded (grade I-V). The examination allows precise visualization of the urethra, bladder and ureters, which is crucial for an accurate diagnosis.
The examination begins with the introduction of the contrast medium into the bladder. While the bladder is slowly filled, short fluoroscopic checks are carried out to detect both low-pressure and high-pressure reflux. After micturition, final imaging is performed to document any residual urine. Modern fluoroscopy techniques such as pulsed fluoroscopy are used to minimize radiation exposure.
Summary
MCU remains an important method for the diagnosis of VUR and other urological anomalies in children. Despite the radiation exposure, it is indispensable as it allows detailed morphological and functional assessment. Standardized protocols and modern techniques minimize the risk of radiation. Non-radiation alternatives are also available for repeated examinations, which can be used in particular for girls and for follow-up.