Pyelography in Pediatric Imaging
Introduction
Pyelography is a radiological examination of the urinary system using contrast media to visualize the collecting systems, ureters, and bladder.
Key Points
- Essential diagnostic tool in pediatric urology
- Provides detailed anatomical and functional information
- Multiple techniques available based on clinical indication
- Requires careful consideration of radiation exposure
- Contrast media selection crucial in pediatric population
Types and Techniques
Intravenous Pyelography (IVP)
- Characteristics
- Systemic administration of contrast
- Sequential imaging during excretion
- Provides functional information
- Less commonly used in modern practice
- Indications
- Evaluation of renal function
- Assessment of collecting system anatomy
- Screening for congenital anomalies
Retrograde Pyelography
- Characteristics
- Direct injection of contrast via cystoscopy
- Higher resolution of upper tract anatomy
- Requires anesthesia in children
- Can be therapeutic and diagnostic
- Indications
- Evaluation of upper tract obstruction
- Pre-operative planning
- Assessment of complex anomalies
Antegrade Pyelography
- Characteristics
- Contrast injection via nephrostomy
- Direct visualization of collecting system
- Can be combined with intervention
- Indications
- Evaluation of obstruction
- Guide percutaneous procedures
- Post-operative assessment
Procedure Details
Patient Preparation
- Pre-procedure Assessment
- Renal function tests
- Allergy history
- Hydration status
- Infection screening
- Fasting Requirements
- Age-appropriate NPO guidelines
- Clear fluid allowance
- Medication considerations
Contrast Media Considerations
- Types of Contrast
- Low-osmolar contrast media preferred
- Iso-osmolar agents for high-risk cases
- Volume calculations based on weight
- Safety Measures
- Pre-hydration protocols
- Emergency preparedness
- Monitoring requirements
Imaging Protocol
- Standard Views
- KUB (preliminary)
- Early nephrographic phase
- Pyelographic phase
- Post-void images
- Special Views
- Oblique projections
- Delayed imaging
- Compression techniques
Clinical Applications
Primary Indications
- Congenital Anomalies
- UPJ obstruction
- Duplicated collecting systems
- Ectopic ureters
- Ureteroceles
- Acquired Conditions
- Urolithiasis
- Post-traumatic evaluation
- Iatrogenic injuries
- Tumor assessment
Specific Clinical Scenarios
- Pre-operative planning for reconstructive surgery
- Post-operative surveillance
- Complex urological anomalies
- Interventional procedure guidance
Image Interpretation
Normal Anatomy
- Calyceal patterns and variations
- Ureteral course and caliber
- Age-specific considerations
- Normal variants
Pathological Findings
- Obstruction Patterns
- Delayed excretion
- Hydronephrosis grading
- Filling defects
- Anatomical Abnormalities
- Duplex systems
- Fusion anomalies
- Malrotation
Quality Assessment
- Adequate contrast opacification
- Proper positioning
- Complete anatomical coverage
- Technical adequacy
Special Considerations
Radiation Protection
- ALARA Principles
- Dose optimization techniques
- Pulsed fluoroscopy
- Collimation strategies
- Lead shielding
- Documentation
- Dose recording
- Exposure parameters
- Quality indicators
Complications Management
- Contrast-Related
- Allergic reactions
- Extravasation
- Nephrotoxicity
- Procedure-Related
- Infection
- Bleeding
- Pain management
Alternative Imaging Modalities
- Ultrasound
- CT urography
- MR urography
- Nuclear medicine studies
