Aims and objectives
X-ray diagnoses for detection of lesion locations,
such as,
various cancer and inflammatory disorders are in widespread use at hospitals around the world.
Up to now,
dose exposure has increased because a sufficient dose is need for a high quality image which supports an accurate X-ray diagnosis.
As a result,
many researches investigate the improvement of image quality.
On the other hand,
little is reported on a dose measurement for management of the personal exposed dose.
For a proper management of medical irradiations,
entrance skin...
Methods and materials
In our experiments,
X-ray irradiations were carried out using the diagnostic X-ray equipment (Toshiba medical systems corporation,
MRAD-A 50S/70).
The nanoDot OSL dosimeter and the microStar (Landauer incorporation) were also used as shown in Fig.2.
Figure 4a) shows a schematic drawing of the counting system in the microStar system.
The measured value “count” is obtained by counting the blue light photon.
Figure 4b-1) and -2) represent energy levels [4,
13] of the nanoDot dosimeter.
In Fig.4b-1),
when X-ray is irradiated the nanoDot dosimeter,
electrons are...
Results
Figure 7 shows two calibration curves obtained by two experimental conditions of free air (Setup A of the left figure) and using the phantom (Setup B of the right figure).
The horizontal and vertical axes in each figure show air-kerma or ESD and counts/e,
respectively.
Here,
e represents an intrinsic detection efficiency.
These axes represent the logarithmic expression.
In the left figure,
the counts are proportional to the air-kerma as shown in the red straight line.
In the right figure,
the relationship between the counts...
Conclusion
In this study,
we derived the calibration curves which have a relationship between the counts of the nanoDot dosimeter and the air-kerma and ESD estimated by an ionization chamber.
We performed two different experiments: free air condition and using the phantom.
As a result,
we found that these calibration curves were consistent with each other.
Accuracy of the calibration curve was estimated to be 10%.
The nanoDot dosimeter is expected to be a convenient dosimeter for the measurement of personal exposed dose in clinical settings....
Personal information
Kazuki Takegami,
Graduate school of Health Sciences,
Tokushima University,
Tokushima,
Japan;
[email protected]
References
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Physics in Medical and Biology 34(12),
1871-1882,
1989.
[3] Grosswendt B: Dependences of the photon backscatter factor for water on source-to-phantom distance and irradiation field size,
Physics in Medical and Biology 35(9),
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1990.
[4] Jursinic PA: Characterization of optically stimulated luminescent dosimeters,
OSLDs,
for...