Positron Emission Tomography (PET) Scan
Positron Emission Tomography (PET)
PET is an advanced molecular imaging technique that uses radioactive tracers to visualize physiological processes at the cellular level. It provides functional information about metabolism, perfusion, and receptor density.
Key Principles
- Based on positron emission decay
- Uses radiolabeled tracers
- Measures metabolic activity
- Often combined with CT (PET/CT) or MRI (PET/MRI)
Common Radiotracers
- 18F-FDG (Fluorodeoxyglucose)
- Most commonly used
- Glucose metabolism marker
- Half-life: 110 minutes
- Other Tracers
- 11C-methionine: Amino acid metabolism
- 18F-DOPA: Dopaminergic system
- 68Ga-DOTATATE: Neuroendocrine tumors
Oncologic Applications
- Primary Diagnosis
- Tumor characterization
- Disease staging
- Metastatic evaluation
- Common Pediatric Malignancies
- Lymphoma
- Neuroblastoma
- Brain tumors
- Sarcomas
- Treatment Monitoring
- Response assessment
- Residual disease detection
- Recurrence surveillance
Neurologic Applications
- Epilepsy
- Seizure focus localization
- Pre-surgical planning
- Post-surgical evaluation
- Brain Development
- Neurodevelopmental disorders
- Metabolic disorders
- Cognitive function assessment
Cardiac Applications
- Myocardial viability
- Inflammatory conditions
- Congenital heart disease
Image Acquisition
- Scanner Requirements
- High-resolution PET detector
- Time-of-flight capability
- Integrated CT or MRI
- Data Collection
- 3D acquisition mode
- Attenuation correction
- Motion correction
- Image Reconstruction
- Iterative reconstruction
- Time-of-flight processing
- Resolution recovery
Radiation Considerations
- Dose Optimization
- Weight-based tracer dosing
- CT protocol optimization
- Scan time adjustment
- Radiation Protection
- ALARA principle
- Shielding requirements
- Exposure monitoring
Patient Preparation
- Pre-scan Requirements
- Fasting guidelines
- Blood glucose monitoring
- Activity restrictions
- Hydration status
- Pediatric Considerations
- Anesthesia/sedation needs
- Temperature control
- Comfort measures
- Parent education
Imaging Protocols
- Standard Protocols
- Whole-body imaging
- Brain protocols
- Cardiac protocols
- Protocol Optimization
- Age-specific modifications
- Disease-specific protocols
- Multi-time-point imaging
- Quality Control
- Scanner calibration
- Image quality assessment
- Standardization measures
Interpretation Guidelines
- Quantitative Analysis
- SUV measurements
- Metabolic tumor volume
- Total lesion glycolysis
- Visual Assessment
- Normal variation patterns
- Age-related changes
- Physiologic uptake
