Determination of size-specific exposure settings in dental cone-beam CT

TY - JOUR

T1 - Determination of size-specific exposure settings in dental cone-beam CT

AU - Pauwels, Ruben

AU - Jacobs, Reinhilde

AU - Bogaerts, Ria

AU - Bosmans, Hilde

AU - Panmekiate, Soontra

PY - 2017/1

Y1 - 2017/1

N2 - To estimate the possible reduction of tube output as a function of head size in dental cone-beam computed tomography (CBCT).A 16 cm PMMA phantom, containing a central and six peripheral columns filled with PMMA, was used to represent an average adult male head. The phantom was scanned using CBCT, with 0-6 peripheral columns having been removed in order to simulate varying head sizes. For five kV settings (70-90 kV), the mAs required to reach a predetermined image noise level was determined, and corresponding radiation doses were derived. Results were expressed as a function of head size, age, and gender, based on growth reference charts.The use of 90 kV consistently resulted in the largest relative dose reduction. A potential mAs reduction ranging from 7 % to 50 % was seen for the different simulated head sizes, showing an exponential relation between head size and mAs. An optimized exposure protocol based on head circumference or age/gender is proposed.A considerable dose reduction, through reduction of the mAs rather than the kV, is possible for small-sized patients in CBCT, including children and females. Size-specific exposure protocols should be clinically implemented.aEuro cent Fixed exposure settings in CBCT results in overexposure for smaller patientsaEuro cent For children, considerable dose reduction is possible without compromising image qualityaEuro cent A reduction in mAs is more dose-efficient than a kV reductionaEuro cent An optimized exposure protocol was proposed based on phantom measurementsaEuro cent This protocol should be validated in a clinical setting.

AB - To estimate the possible reduction of tube output as a function of head size in dental cone-beam computed tomography (CBCT).A 16 cm PMMA phantom, containing a central and six peripheral columns filled with PMMA, was used to represent an average adult male head. The phantom was scanned using CBCT, with 0-6 peripheral columns having been removed in order to simulate varying head sizes. For five kV settings (70-90 kV), the mAs required to reach a predetermined image noise level was determined, and corresponding radiation doses were derived. Results were expressed as a function of head size, age, and gender, based on growth reference charts.The use of 90 kV consistently resulted in the largest relative dose reduction. A potential mAs reduction ranging from 7 % to 50 % was seen for the different simulated head sizes, showing an exponential relation between head size and mAs. An optimized exposure protocol based on head circumference or age/gender is proposed.A considerable dose reduction, through reduction of the mAs rather than the kV, is possible for small-sized patients in CBCT, including children and females. Size-specific exposure protocols should be clinically implemented.aEuro cent Fixed exposure settings in CBCT results in overexposure for smaller patientsaEuro cent For children, considerable dose reduction is possible without compromising image qualityaEuro cent A reduction in mAs is more dose-efficient than a kV reductionaEuro cent An optimized exposure protocol was proposed based on phantom measurementsaEuro cent This protocol should be validated in a clinical setting.

KW - Cone-beam computed tomography

KW - Dentistry

KW - Paediatrics

KW - Radiation protection

KW - Noise

KW - CHILDREN

U2 - 10.1007/s00330-016-4353-z

DO - 10.1007/s00330-016-4353-z

M3 - Journal article

SN - 0938-7994

VL - 27

SP - 279

EP - 285

JO - European Radiology

JF - European Radiology

IS - 1

ER -