Radiation safety
CT / Fluoro Effective Dose Estimator
Convert scanner-reported DLP or exposure data into effective dose to support justification, optimization, and patient counseling. Coefficients are approximations—consult protocol-specific conversion factors for precision.
Coefficient: 0.0140 mSv per mGy·cm.
Use scanner reported DLP. For fluoroscopy, convert Air Kerma × Field Length if available.
Sum exposures from multiple scans (e.g., multiphase CT).
Add prior studies or background dose if tracking cumulative exposure.
Effective dose (single study)
6.30 mSv
ICRP 103
Cumulative effective dose
6.30 mSv
Includes repeated studies and additional inputs.
Typical of limited CT or radiography protocols. Continue dose optimization and documentation.
How to Use This Calculator
Record scanner-reported metrics
Use DLP for CT or dose-area product/air kerma linear measurements for fluoroscopy.
Select an appropriate conversion factor
Choose the region closest to the scanned anatomy. Update coefficients with institution-specific values if available.
Document and compare cumulative dose
Track patient exposure across episodes to apply ALARA and inform patient counseling.
Formula
Effective dose (mSv) = DLP (mGy·cm) × Region conversion coefficient (mSv / mGy·cm)
Cumulative dose = Effective dose × Number of studies + Additional doses
Coefficients approximate ICRP tissue weighting factors; adjust per institution protocols.
Full Description
Effective dose expresses stochastic risk from heterogeneous radiation exposures. It is derived from organ dose estimates and tissue weighting factors, allowing comparison across modalities. Although useful for patient communication and benchmarking, effective dose is a population-based estimate—not a patient-specific risk guarantee.
For individualized dosimetry (pediatrics, research, pregnancy), use Monte Carlo simulations or organ-based software. Continue implementing dose-reduction strategies such as automatic exposure control, iterative reconstruction, and protocol standardization.
Frequently Asked Questions
Are these coefficients accurate for children?
Pediatric conversion factors differ. Use age-specific tables (e.g., AAPM Report 204, 221) for pediatric CT dosimetry.
How do I convert mGy to mSv directly?
mGy is absorbed dose; mSv accounts for tissue sensitivity. Use coefficient (mSv/mGy·cm) rather than direct conversion.
Can I add background radiation?
Yes. Average annual background ≈ 3 mSv (global). Include under “Additional dose” if discussing total yearly exposure.
Does effective dose predict deterministic effects?
No. Deterministic (threshold) effects depend on local organ dose, not effective dose. Use organ-specific dosimetry when relevant.