Anomalies of the distal ureter, bladder, and urethra in children: embryologic, radiologic, and pathologic features

Area of Science:

• Pediatric Radiology
• Urology
• Medical Imaging

Background:

• Congenital anomalies of the lower urinary tract are a common cause of infant morbidity.
• Radiologic imaging is crucial for diagnosis but must balance information gain with patient safety and timely treatment.

Purpose of the Study:

• To review radiologic investigation methods for congenital lower urinary tract anomalies in pediatric patients.
• To emphasize the appropriate use of various imaging modalities for accurate diagnosis and management.

Main Methods:

• Initial screening with ultrasonography for suspected structural anomalies.
• Voiding cystourethrography to assess for vesicoureteral reflux (VUR) and upper tract dilatation.
• Nuclear cystography, echo-enhanced cystosonography, and nuclear diuresis renography for VUR assessment and megaureter differentiation.
• Intravenous urography for obstruction, duplex systems, and ureteroceles.
• CT and MRI for detailed anatomy and associated spinal anomalies; MR urography for ectopic ureteric insertions.

Main Results:

• Ultrasonography is the common initial study.
• Voiding cystourethrography is key for VUR detection.
• Nuclear imaging and IV urography help differentiate obstruction and identify specific anomalies.
• Advanced imaging like MRI provides detailed anatomy and is essential for spinal anomaly evaluation.

Conclusions:

• A stepwise approach using various radiologic modalities is essential for diagnosing congenital lower urinary tract anomalies.
• Familiarity with these imaging techniques ensures correct diagnosis and guides appropriate patient management.
• Advanced imaging like MR urography offers comprehensive views of complex malformations.