Abstract
Objectives: To estimate the radiation dose reduction to the thyroid for an anterior oblique occlusal view from the use of a thyroid shield, compare this with the variation in thyroid dose resulting from differences in examination positioning and discuss the additional considerations associated with the use of a thyroid shield before making a recommendation on their routine use for this examination. Methods: Doses to the oral mucosa, the salivary glands, the thyroid, the extrathoracic airways, the oesophagus and the lungs were directly measured for anterior oblique occlusal X-rays of a Rando phantom with and without a thyroid shield using strips of calibrated XRQA Gafchromic film. The examination was also simulated using Monte Carlo software for the without thyroid shield case for a comparison of the dose and to evaluate the dosimetric effect of suboptimal examination positioning.Results: A 36% reduction in thyroid dose was measured as a result of thyroid shield use; the effective dose reduction is of the order of 22%. Suboptimal positioning was found to increase thyroid dose by a far more significant amount. Conclusions: Despite the reduction in thyroid dose, cost-benefit considerations mean that the purchase of a thyroid shield is only recommended where a very high number of anterior oblique occlusal views are undertaken. Optimization efforts for this examination are better focussed on training in examination positioning.
Original language | English |
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Article number | 20170140 |
Pages (from-to) | 1-11 |
Number of pages | 11 |
Journal | Dentomaxillofacial Radiology |
Volume | 47 |
Issue number | 1 |
Early online date | 27 Oct 2017 |
DOIs | |
Publication status | Published - 2018 |
Keywords
- Radiography
- thyroid gland
- Thyroid gland
- Diagnostic Imaging
- Humans
- Radiation Protection/instrumentation
- Software
- Thyroid Gland/radiation effects
- Radiation Dosage
- Phantoms, Imaging
- Monte Carlo Method
ASJC Scopus subject areas
- General Dentistry
- Radiology Nuclear Medicine and imaging
- Otorhinolaryngology