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Pediatric Radiology

, Volume 47, Issue 13, pp 1737–1744 | Cite as

Radiation risk index for pediatric CT: a patient-derived metric

  • Ehsan Samei
  • Xiaoyu Tian
  • W. Paul Segars
  • Donald P. FrushEmail author
Original Article

Abstract

Background

There is a benefit in characterizing radiation-induced cancer risk in pediatric chest and abdominopelvic CT: a singular metric that represents the whole-body radiation burden while also accounting for age, gender and organ sensitivity.

Objective

To compute an index of radiation risk for pediatric chest and abdominopelvic CT.

Materials and methods

Using a protocol approved by our institutional review board, 42 pediatric patients (age: 0-16 years, weight: 2-80 kg) were modeled into virtual whole-body anatomical models. Organ doses were estimated for clinical chest and abdominopelvic CT examinations of the patients using validated Monte Carlo simulations of two major scanner models. Using age-, size- and gender-specific organ risk coefficients, the values were converted to normalized effective dose (by dose length product) (denoted as the k factor) and a normalized risk index (denoted as the q factor). An analysis was performed to determine how these factors are correlated with patient age and size for both males and females to provide a strategy to better characterize individualized risk.

Results

The k factor was found to be exponentially correlated with the average patient diameter. For both genders, the q factor also exhibited an exponential relationship with both the average patient diameter and with patient age. For both factors, the differences between the scanner models were less than 8%.

Conclusion

The study defines a whole-body radiation risk index for chest and abdominopelvic CT imaging, that incorporates individual estimated organ dose values, organ radiation sensitivity, patient size, exposure age and patient gender. This indexing metrology enables the assessment and potential improvement of chest and abdominopelvic CT performance through surveillance of practice dose profiles across patients and may afford improved informed communication.

Keywords

Children Computed tomography Effective dose Radiation dose Radiation risk 

Notes

Compliance with ethical standards

Conflicts of interest

None.

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Copyright information

© Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  • Ehsan Samei
    • 1
    • 2
    • 3
  • Xiaoyu Tian
    • 1
  • W. Paul Segars
    • 1
    • 3
  • Donald P. Frush
    • 3
    • 4
    Email author
  1. 1.Department of Radiology, Carl E. Ravin Advanced Imaging LaboratoriesDuke University Medical CenterDurhamUSA
  2. 2.Department of Biomedical Engineering, Electrical and Computer EngineeringDuke University Medical CenterDurhamUSA
  3. 3.Medical Physics Graduate ProgramDuke University Medical CenterDurhamUSA
  4. 4.Division of Pediatric Radiology, Department of RadiologyDuke University Medical CenterDurhamUSA

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