• Journal of radiological science and technology
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• v.3 no.1
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• pp.67-72
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• 1980

To shield the radiation, we can make use of various materials, but the scattered rays can be caused by the shielding materials. The degree of the scattered rays production is influenced by the nature of the shielding materials and the energy of the radiation, therefore to choose the proper shielding material is the most important matter in radiation protection. Authors made an experimental study on the scattered rays generated from the shielding materials, and obtained the results as follows: 1. In the ranking of the scattered rays production: Cement bricks, black colored fire bricks, and red colored fire bricks were marked the first the second, and the third ranking respectly, and the last order was lead plates. 2. In the relative ranking of the scattered rays production by energy increase: Lead plates were marked the first order, the next and third order were red colored fire bricks and black colored fire bricks respectly, and cement bricks were marked the last order. 3. The scattered ray ratio of lateral-back point per lateral point were generally decreased by energy increment. The diminishing orders were that lead plates were the first order, and the next and the third order were red colored fire bricks and black colored fire bricks respectly, cement bricks were marked the last order.

• Journal of Radiation Protection and Research
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• v.47 no.1
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• pp.39-49
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• 2022

Background: For proper monitoring of the eye lens dose, an appropriate calibration factor of a dosimeter and information about the mean energies of X-rays are indispensable. The scattered X-ray energy spectra should be well characterized in medical practices where eye lenses of medical staffs might be high. Materials and Methods: Scattered X-ray energy spectra were experimentally derived for three different types of X-ray diagnostic and therapeutic equipment, i.e., the computed tomography (CT) scan, the angiography and the fluoroscopy. A commercially available CdZnTe (CZT) spectrometer with a lead collimator was employed for the measurement of scattered X-rays, which was performed in the usual manner. Results and Discussion: From the obtained energy spectra, the mean energies of the scattered X-rays lied between 40 and 60 keV. This also agreed with that obtained by the conventional half value layer method. Conclusion: The scattered X-rays to which medical workers may be exposed in the region around the eyes were characterized by means of spectrometry. The obtained mean energies of the scattered X-rays were found to match the flat region of the dosimeter response.

• Journal of radiological science and technology
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• v.11 no.2
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• pp.3-15
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• 1988

When X-rays were projected into a patient, there occured the phenomena such as penetration, absorption and scattering etc. The penetrating rays were recorded on films as X-ray image used for diagnosis but scattered rays caused the radiation hazard both to the patient, specialist and technicians. The soft tissue includes many organs which are sensitive to the radiation and in may occupy $40{\sim}50%$ of body weight. Therefore X-rays should be carefully projected to the patient and it is strongly recommended to analyse the distribution of X-rays, when ever the patient is exposed to X-rays. In this study, the distribution of X-ray according to the thickness, the radiation field and the tube voltages (kVp) in soft tissue, the following results were obtained: 1. Total transmitted rays which kept the step with X-ray tube voltage (kVp) increased in proportion to the increasing of X-ray tube voltage. 2. The scattered ray rate in the total transmitted ray was not significantly found with X-ray tube voltage. 3. The affecting factors of the scattered ray rate in total transmitted ray were shown through the radiation field and the thickness. 4. The dose of scattered ray by the angle was observed more in direction of primary ray ($0^{\circ}$) and back scattering ($160^{\circ}$) than in direction of $90^{\circ}$. 5. The more the distance from phantom to the patient should be less distribution of scattered ray.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.404-406
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• 2002

We have investigated the contribution of the scattered x rays to the signal imaging in the radiographs acquired with anti-scatter grids of several grid ratios by separating the line spread functions (LSFs) derived from the signal edge image into the primary and the scatter components. By using a 1.0-mm lead plate in the scattering material, the blurred signal edge images were acquired by use of an imaging plate at a tube voltage of 80 kV with the anti-scatter grids of grid ratios for 5:1, 6:1, 8:1, 10:1 and 12:1. The edge profiles of the signal images were scanned and those in relative exposure were differentiated to obtain the LSFs. To investigate the contribution of the scattered x rays to the signal imaging, we proposed a method for separating the LSFs derived from the signal images into the primary and the scatter components, where the scatter component was approximated with exponential function. Our basic approach is to separate the area of the LSFs by ratios of the scattered x-ray exposure to the primary x-ray exposure, which were obtained for the grid ratios by use of a lead disk method. The LSFs and the two components were Fourier transformed to obtain the modulation transfer functions (MTFs) and their two components. As the result, we found that, by using the anti-scatter grids, the scattered x rays were reduced, but the shape of the LSFs of the scatter component hardly changed. The contributions of the scatter component to the MTFs were not negligible (more than 10 %) for spatial frequencies lower than about 1.0 mm$\^$-l/ and that was greater as the grid ratio decreasing. On the other hand, for higher frequencies, the primary component was dominant compared with the scatter component.

• Journal of the Korean Society of Radiology
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• v.10 no.1
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• pp.15-19
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• 2016

This Study aims at measuring scattered rays depending on the use of a flattening filter when radiation is irradiated using a linear accelerator. measurement of the scattered rays, an ionization chamber was used, and the energy of the irradiated radiation was 6 MV and 10 MV. The ionization chamber was located at the spot 15 cm, 25 cm, 35 cm and 45 cm far away from the center of gantry rotation, and the scattered rays were measured according to whether a flattening filter was used or not and to the distance. As the result of investigation of 100 cGy about each energy, when the flattening filter was not used with 6 MV, it occurred at a low level of 65%, and with 10 MV at that of 55%. In other words, it's been concluded that when a flattening filter is not used for radiation dose of the parts around the critical organ, scattered rays generate in a small quantity, and it's a useful way to decrease the stochastic effect of radiation.

• Journal of radiological science and technology
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• v.23 no.2
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• pp.69-73
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• 2000

This paper studied a C-arm's exposure condition and measured scatter rays by thickness and distance. This study reached the following conclusion. 1. Approrimately exposure dose for a patient using fluoroscopy is as follows : 2. Mostly, an operating room was not shielding by lead and operator put on only apron without thyroid and facial part protection. 3. 0.5 mmPb equivalent's apron shielded about 99% of scattered rays at 60 cm from x-ray tube. 4. Scattered rays are depended on distance and thickness so operators are should be careful when using fluoroscopy by C-arm and if possible use high frequency equipment that has a large output.

• Journal of Radiation Industry
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• v.11 no.3
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• pp.167-171
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• 2017

This study examined the effectiveness degree of a protective apron that is taken not to be exposed to the first ray or scattered rays, for X-ray of thick subject like lateral lumbar, and the results are as follows; First, spatial dose by scattered rays is shielded by 3 mmPb protective apron, 86.8% at a distance of 50 cm, 92.7% at 100 cm, and 95.6% at 200 cm, when minimizing the field size, while 89% at a distance of 50 cm, 92.3% at 100 cm, and 95.2% at 200 cm, when maximizing the field size. Second, 1st exposure dose is shielded by 3 mmPb protective apron, 93.7% at a distance of 50 cm, 94.4% at 100 cm, and 93.6% at 200 cm, when minimizing the field size, while 93.7% at a distance of 50 cm, 93.6% at 100 cm, and 94.2% at 200 cm, when maximizing the field size.

• Journal of radiological science and technology
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• v.47 no.1
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• pp.13-19
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• 2024

Control of scattered radiation is one of very important factors in the use of medical radiation. In general X-ray exam, the causes, measurement methods, and the kind of detectors of scattered rays within the radiation area are diverse. In this study, the dose of scattered ray was measured by changing the thickness of the polycarbonate phantom and the tube voltage. As a result of measurement of scattered radiation, the results show that the scattered dose significantly(p<.05) increased with growing of thickness of phantom in the tube voltage 40, 50 and 60 kVp(F(p)<.05, R²>64%). As tube voltage increased at all phantom thicknesses, the scattered dose also significantly(p<.05) increased(F(p)<.05, R²>69%). In cases where a significant correlation was shown, the coefficient of determination of more than 60% was shown in regression analysis. The results of this study can be used as data on scattered radiation dose according to the tube voltage and the object thickness in general X-ray imaging exam.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.4
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• pp.177-183
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• 2011

This study intends to investigate patients' exact exposure doses by comparatively measuring ESD (Entrance Surface Dose) with the DAP meter, which excludes scattered rays, and ESD with the Xi multifunction meter, which includes scattered rays, by posture changes for Esophagography test and UGI test. The materialwere examined through Sonialvision-SafireII SPEC overtube system. ESD was measured by using the DAP meter, and as a tool to measure ESD including scattered rays on the plane of incidence of human phantom, the Xi multifunction meter was used. The average fluoroscopic time of Esophagography test was 4.192 minutes and the average number of images was 47.7, while the average fluoroscopic time of UGI test was 6.881 minutes and the average number of images was 37.8. The ratios of the incident dose of DAP meter and the ESD of Xi meter were calculated bydividing the fluoroscopic time and the number of images by each posture change. As for Esophagography test, the dose increased by 21.6~55.5% in the fluoroscopic test and by 4.8~24.7% in the spot test. In the front spot test, however, the does increased by as little as 5.3%. As for UGI test, the dose increased by 21.1~49.5% in the fluoroscopic test and by 10.1~34.9% in the spot test. It is expected that measuring doses in consideration of scattered rays by posture changes will be an important index in evaluating and managing patients' exact exposure doses for each test above. Furthermore, it is judged that this sort of study is inevitable and desirable to reduce patients' exposure doses after all.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.6-7
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• 2009

We proposed the two-dimensional (2D) / three-dimensional (3D) convertible modified integral imaging system using functional polarizing film named $imazer^{TM}$, which transfer or scatter the incident light ray according to the polarizing direction of ray. When the incident light rays transfer to $imazer^{TM}$, the rays generate 3D image through the process of the modified integral imaging system. However, the scattered light rays generate 2D image through the simple backlight scheme when the incident rays are scattered by the film. The proposed method can be implemented the partial 3D display system without any mechanical movements. In this paper, we propose and verify our system using some basic experiments and its results.