Purpose
Measure entrance surface dose into the crystalline,
thyroid and body,
in an anthropomorphic phantom,
in panoramic radiography exams.
Check the efficiency of radiological protections,
and compare to the diagnostic reference levels and other studies.
Methods and materials
This is a quantitative experimental study.
The sampling method consisted of measuring the dose within the crystalline,
thyroid gland and body,
subject to Orthopantomography tests in a standard and pediatric protocol,
in order to compare the results with the reference dose levels and other previous studies.
The measurement was initially held without protection and subsequently with the respective safeguards with a total of 20 exposures.
Instruments:
GE Orthopantomography OP 100
Dosimeter AT1123 Atomtex
Thermoluminescent dosimeters
Anthropomorphic phantom
Barium protection for the lens (equivalent to 0,125mm...
Results
The average exposure parameters are shown on table 2.
For the ESD measurements on the crystalline dosimeters 1,
4,
7 and 10 were used (table 3).
Table 2: Exposures Mean and Standard Deviation
Mean and Standard Deviation
Voltage (kV)
Current (mA)
Time (s)
70 kV
6,72 mA ± 2,59
17,6s
Table 3: Dose on the Crystalline
Standard Exam
Paediatric Exam
Without radiological protection (mGy)
0,022
0,027
With radiological protection (mGy)
0,034
0,052
For the thyroid,
dosimeters 2,
5,
8 and 11 (table 4).
Table 4:...
Conclusion
Through the measurements on the phantom,
the ESD the crystalline,
thyroid and body,
does not exceed the DRL stipulated by the European Guidelines (0.7 mGy).
Compared to values reported in other studies,
the ESD measured in the lens is about average with 0.022 mGy analyzed in standard examinations and slightly higher in pediatric examinations (0.027 mGy).
The efficiency level of protection used is concluded that barium protection use in panoramic radiography examinations DEP increases the level of the lens in an anthropomorphic phantom in 35.3%...
References
Melgar,
J.,
et al.
(2004).
Estimación de dosis a paciente en estúdios de ortopantomografia.
Revista de Física médica.
European Guidelines.
(2004).
Radiation Protection: European guidelines on radiation protection in dental radiology.
Nº136.
Luxemburgo.
ATOMTEX.
(2015).
Instruments and Technologies for Nuclear Measurements and Radiation Monitoring.
Consultado a 15 de Maio de 2015 através de http://www.atomtex.com/en/products/portable-dosimeters/at1121-at1123-x-ray-and-gamma-radiation-dosimeters
GE Healthcare.
(2004).
Orthopantomograph® OP100.
DOrthoceph® OC100 D – User & Technical Manual.
Consultado a 22 de Maio de 2014 através de https://pattersonsupport.custhelp.com/euf/assets/Digital/GE/OP1000_Manual.pdf?nointercept/1
ICRP 103 (2007).
The 2007 Recommendations of the...