OSL dosimeters for dental panoramic radiography.

The aim of the present work is to determine dosimetric characteristics of commercial optically stimulated luminescence dosimeter (OSLD) to estimate equivalent dose in the patient undergoing panoramic radiography procedure. Digital panoramic unit "Instrumentarium OP200D" was used. OSL dosimeters were optically bleached before any exposure procedure. InLight™ OSL nanodosimeters were placed on the thyroid surface between the head and neck. The exposure parameters for all measurements was standard value consisted in 66 kV, 5 mA, and 14.1 s. Standard size field of view (FOV) scanning mode was used. Dosimeters were calibrated for the air kerma. Reported male adult equivalent doses from 21 to 45 µSv for each scanning for standard size field of view (FOV). Meanwhile reported female adult equivalent doses from 28 to 75 µSv for standard size field of view (FOV) considering all heights. The lowest equivalent dose (21 µSv) was observed in the male thyroid gland surface (S) position for medium height. The highest equivalent dose (75 µSv) was for female small height in the right parotid surface (R) position. In conclusion, the results demonstrate that OSL dosimeters are appropriate in vivo dosimetry system for dental panoramic dose measurements.

Eye lens dose levels in interventional rooms using simple phantom simulation, dose management software and Monte Carlo method of uncertainty assessment.

This paper presents a fast method to estimate the annual eye lens dose levels for interventional practitioners applying the Monte Carlo method of uncertainty assessment. The estimation was performed by placing an anthropomorphic phantom in the typical working position, and applying the habitually employed protocol. No radiation protection devices were considered in the simulation. The results were compatible with the measurements performed during interventions by placing dosimeters in the vicinity of the eyes of two paediatric interventional cardiologists working with a fluoroscopic biplane system.

Measurement models for passive dosemeters in view of uncertainty evaluation using the Monte Carlo method.

Two measurement models for passive dosemeters such as thermoluminescent dosemeter, optically stimulated luminescence, radio-photoluminescence, photographic film or track etch are discussed. The first model considers the dose evaluation with the reading equipment as a single measurement, the one-stage model. The second model considers the build-up of a latent signal or latent image in the detector during exposure and the evaluation using a reader system as two separate measurements, the two-stage model. It is discussed that the two-stage model better reflects the cause and effect relations and the course of events in the daily practice of a routine dosimetry service. The one-stage model will be non-linear in crucial input quantities which can give rise to erroneous behavior of the uncertainty evaluation based on the law of propagation of uncertainty. Input quantities that show an asymmetric probability distributions propagate through the one-stage model in a physically not relevant way.