Related Experiment Video
Updated: Aug 6, 2026

Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection
Published on: October 12, 2017
The role of micturating cystourethrography in antenatally detected mild hydronephrosis
C R Pal1, J R Tuson, D R Lindsell
1Department of Radiology, John Radcliffe Hospital, Headington, Oxford, UK.
Background:
The postnatal imaging of infants with antenatally detected mild hydronephrosis remains controversial.
Objective:
Our aim was to establish the role and timing of micturating cystourethrography (MCUG) in mild hydronephrosis.
Materials And Methods:
We performed a retrospective study of 61 infants (122 kidneys) referred with an antenatal diagnosis of hydronephrosis who showed persistent postnatal dilatation. All had follow-up postnatal ultrasound (US) and MCUG performed. The degree of dilatation at each follow-up scan was recorded.
Results:
Of the 122 kidneys, 65 showed mild hydronephrosis. A substantial proportion of these (21.5%) demonstrated reflux. Serial US of these infants showed that the 6-week scan was the most informative and that any changes that warranted further investigation had occurred by this time.
Conclusion:
We recommend that all infants with mild hydronephrosis should undergo MCUG. MCUG need not be delayed until 3 months but could be performed following a 6-week US scan.
Related Concept Videos
The Micturition Reflex
The process begins with bladder filling, where the bladder wall stretches as urine accumulates. This stretching activates the urine storage reflex, mediated by the sacral spinal segments and the pontine storage center. Efferent sympathetic impulses stimulate the detrusor muscle to relax and the internal urethral sphincter to contract, facilitating urine...
Imaging Studies II: Ultrasonography
Imaging Studies IV: Magnetic Resonance Imaging
Imaging Studies V: Intravenous Urography and Retrograde Pyelography
Imaging Studies VI: Voiding Cystourethrography and Cystography
Urologic Endoscopic Procedure: Cystoscopic Examination

