Dosimetry of 3 CBCT devices for oral and maxillofacial radiology: CB Mercuray, NewTom 3G and i-CAT

Ludlow, John B.; Davies-Ludlow, LE; Brooks, SL; Howerton, William

doi:10.1259/dmfr/14340323

Cited by 679 publications

(177 citation statements)

References 18 publications

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“…6 Patient doses from CBCT are significantly higher than from conventional dental radiography techniques. [7][8][9][10] The dose absorbed by the uterus has been used as a surrogate for the dose absorbed by the embryo and foetus in medical radiation dosimetry. 11 Initially, uterine exposure to radiation during dental X-ray examinations has been determined by, for example, Weber et al 12 and Orsini et al 12,13 The mean organ dose in the uterus for the most common examination procedures was 0.4 mSv per radiograph; a protective apron reduced this dose by a factor of two.…”

Section: Introductionmentioning

confidence: 99%

Radiation exposure to foetus and breasts from dental X-ray examinations: effect of lead shields

Kelaranta

Ekholm

Toroi

et al. 2016

Dentomaxillofacial Radiology

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Objectives: Dental radiography may involve situations where the patient is known to be pregnant or the pregnancy is noticed after the X-ray procedure. In such cases, the radiation dose to the foetus, though low, needs to be estimated. Uniform and widely used guidance on dental X-ray procedures during pregnancy are presently lacking, the usefulness of lead shields is unclear and practices vary. Methods: Upper estimates of radiation doses to the foetus and breasts of the pregnant patient were estimated with an anthropomorphic female phantom in intraoral, panoramic, cephalometric and CBCT dental modalities with and without lead shields. Results: The upper estimates of foetal doses varied from 0.009 to 6.9 mGy, and doses at the breast level varied from 0.602 to 75.4 mGy. With lead shields, the foetal doses varied from 0.005 to 2.1 mGy, and breast doses varied from 0.002 to 10.4 mGy. Conclusions: The foetal dose levels without lead shielding were ,1% of the annual dose limit of 1 mSv for a member of the public. Albeit the relative shielding effect, the exposure-induced increase in the risk of breast cancer death for the pregnant patient (based on the breast dose only) and the exposure-induced increase in the risk of childhood cancer death for the unborn child are minimal, and therefore, need for foetal and breast lead shielding was considered irrelevant. Most important is that pregnancy is never a reason to avoid or to postpone a clinically justified dental radiographic examination.

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Section: Introductionmentioning

confidence: 99%

Radiation exposure to foetus and breasts from dental X-ray examinations: effect of lead shields

Kelaranta

Ekholm

Toroi

et al. 2016

Dentomaxillofacial Radiology

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show abstract

“…The radiation doses from full FOV dental CBCT scans have been measured to be 4-42 times the dose from a panoramic radiograph. 4,5 Therefore, the clinicians ordering dental CBCT should be mindful that frequent use of supplemental CBCT results in non-negligible increases in the total radiation dose to the patient. Conclusions of a 2009 systematic review demonstrated that the most common uses of dental CBCT are for maxillofacial surgery (41%), dentoalveolar pathology (29%), orthodontics (16%) and implantology (13%).…”

Section: Introductionmentioning

confidence: 99%

Measuring absorbed dose for i-CAT CBCT examinations in child, adolescent and adult phantoms

Choi

Ford

2015

Dentomaxillofacial Radiology

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“…To date, most studies concerning effective dose assessment have used thermoluminescent dosimeters (TLD) in combination with anthropomorphic phantoms 2 , 3 , 4 , 5 , 6 , 7 . The low‐dose limit of TLDs when using single exposure (0.3 mGy) 8 , 9 has been considered adequate in most applications and has, therefore, been used as the reference low‐dose limit in MOSFET uncertainty assessment in this study.…”

Section: Introductionmentioning

confidence: 99%

Characterization of MOSFET dosimeters for low‐dose measurements in maxillofacial anthropomorphic phantoms

Koivisto

Wolff

Kiljunen

et al. 2015

J Applied Clin Med Phys

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The aims of this study were to characterize reinforced metal‐oxide‐semiconductor field‐effect transistor (MOSFET) dosimeters to assess the measurement uncertainty, single exposure low‐dose limit with acceptable accuracy, and the number of exposures required to attain the corresponding limit of the thermoluminescent dosimeters (TLD). The second aim was to characterize MOSFET dosimeter sensitivities for two dental photon energy ranges, dose dependency, dose rate dependency, and accumulated dose dependency. A further aim was to compare the performance of MOSFETs with those of TLDs in an anthropomorphic phantom head using a dentomaxillofacial CBCT device. The uncertainty was assessed by exposing 20 MOSFETs and a Barracuda MPD reference dosimeter. The MOSFET dosimeter sensitivities were evaluated for two photon energy ranges (50–90 kVp) using a constant dose and polymethylmethacrylate backscatter material. MOSFET and TLD comparative point‐dose measurements were performed on an anthropomorphic phantom that was exposed with a clinical CBCT protocol. The MOSFET single exposure low dose limit (25% uncertainty, normalk=2) was 1.69 mGy. An averaging of eight MOSFET exposures was required to attain the corresponding TLD (0.3 mGy) low‐dose limit. The sensitivity was 3.09±0.13 mV/mGy independently of the photon energy used. The MOSFET dosimeters did not present dose or dose rate sensitivity but, however, presented a 1% decrease of sensitivity per 1000 mV for accumulated threshold voltages between 8300 mV and 17500 mV. The point doses in an anthropomorphic phantom ranged for MOSFETs between 0.24 mGy and 2.29 mGy and for TLDs between 0.25 and 2.09 mGy, respectively. The mean difference was −8%. The MOSFET dosimeters presented statistically insignificant energy dependency. By averaging multiple exposures, the MOSFET dosimeters can achieve a TLD‐comparable low‐dose limit and constitute a feasible method for diagnostic dosimetry using anthropomorphic phantoms. However, for single in vivo measurements (<1.7 mGy) the sensitivity is too low.PACS number: 87.50.wj

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Dosimetry of 3 CBCT devices for oral and maxillofacial radiology: CB Mercuray, NewTom 3G and i-CAT

Abstract: CBCT dose varies substantially depending on the device, FOV and selected technique factors. Effective dose detriment is several to many times higher than conventional panoramic imaging and an order of magnitude or more less than reported doses for conventional CT.

Cited by 679 publications

References 18 publications

Radiation exposure to foetus and breasts from dental X-ray examinations: effect of lead shields

Radiation exposure to foetus and breasts from dental X-ray examinations: effect of lead shields

Measuring absorbed dose for i-CAT CBCT examinations in child, adolescent and adult phantoms

Characterization of MOSFET dosimeters for low‐dose measurements in maxillofacial anthropomorphic phantoms

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