DMSA (Dimercaptosuccinic Acid) Renal Scan
DMSA (Dimercaptosuccinic Acid) Renal Scan
Key Points
- Gold standard for cortical imaging
- Uses Technetium-99m labeled DMSA
- Evaluates differential renal function
- Identifies cortical scarring
- Essential in UTI workup
DMSA scan is a nuclear medicine procedure that provides detailed imaging of renal cortical tissue and accurate assessment of individual kidney function. It's particularly valuable in evaluating renal parenchymal damage and scarring.
Technical Aspects
Radiopharmaceutical Details
- Tracer Properties
- 99mTc-DMSA
- Half-life: 6 hours
- Cortical uptake: 40-50%
- Peak uptake: 2-4 hours
- Dosing Guidelines
- Pediatric dose: 1.85 MBq/kg (minimum 18.5 MBq)
- Adult dose: 70-150 MBq
- Radiation exposure: 0.9-1.0 mSv
- Age-appropriate adjustments
Imaging Protocol
- Patient Preparation
- No specific preparation required
- Good hydration recommended
- Void before imaging
- Remove metallic objects
- Acquisition Parameters
- Timing: 2-4 hours post-injection
- Multiple planar views (posterior, oblique)
- SPECT when indicated
- Image matrix: 256 x 256
Clinical Indications
Primary Indications
- Urinary Tract Infection
- Acute pyelonephritis assessment
- Post-infection scarring
- Follow-up evaluation
- Risk stratification
- Renal Function Assessment
- Differential renal function
- Congenital anomalies
- Multicystic dysplastic kidney
- Ectopic kidney evaluation
Secondary Indications
- Trauma assessment
- Renal infarction
- Horseshoe kidney
- Pre/post-surgical planning
- Transplant kidney evaluation
Image Interpretation
Normal Findings
- Appearance
- Homogeneous cortical uptake
- Sharp cortical margins
- Normal size and position
- Differential function 45-55%
- Quantitative Parameters
- Background-corrected counts
- Relative function calculation
- Size measurements
- Cortical thickness assessment
Pathological Findings
- Acute Changes
- Photopenic areas
- Cortical defects
- Volume changes
- Decreased uptake
- Chronic Changes
- Cortical scarring
- Volume loss
- Permanent defects
- Contour deformities
Clinical Guidelines
Timing Recommendations
- Acute UTI Assessment
- Optimal timing: 4-6 months post-infection
- Earlier if clinically indicated
- Follow-up intervals
- Monitoring Guidelines
- Initial baseline study
- Follow-up protocols
- Risk-based intervals
- Age-specific considerations
Special Considerations
- Technical Factors
- Patient positioning
- Motion artifacts
- Processing parameters
- Quality control measures
- Reporting Standards
- Standardized terminology
- Quantitative measurements
- Comparative analysis
- Clinical correlation
- Integration with Other Modalities
- Ultrasound correlation
- VCUG findings
- Clinical parameters
- Laboratory results
