Realistic phantoms to characterize dosimetry in pediatric CT

Area of Science:

• Medical Physics
• Radiological Dosimetry
• Pediatric Imaging

Background:

• Accurate estimation of organ and effective doses in pediatric CT examinations is crucial.
• Advanced anthropomorphic body models enhance individual organ dose assessment and effective dose calculations.

Purpose of the Study:

• To develop a comprehensive database of organ and effective doses for pediatric patients undergoing CT scans.
• To establish correlations between radiation dose metrics and anthropometric parameters in children.

Main Methods:

• Modified existing pediatric body models to represent diverse height percentiles and ages.
• Simulated chest-abdomen-pelvis CT exams on 80 pediatric reference phantoms.
• Normalized organ and effective doses to dose-length product (DLP) and analyzed their relationship with body diameter.

Main Results:

• DLP-normalized organ doses showed a strong correlation with body diameter (R² > 0.95 for most organs).
• DLP-normalized effective dose demonstrated a very strong correlation with body diameter (R² > 0.99).
• Results exhibited good agreement (approx. 10% difference) with existing studies.

Conclusions:

• A comprehensive dataset of organ and effective doses for 80 pediatric reference phantoms was generated.
• This database can replace vendor-reported doses and enable individual patient dose tracking.
• The data facilitates patient matching and prediction of individualized radiation doses before CT examinations.