• Progress in Medical Physics
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• v.27 no.4
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• pp.272-276
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• 2016

To investigate the optimum x-ray tube design for the dental radiology, factors affecting x-ray beam characteristics such as tungsten target thickness and anode angle were evaluated. Another goal of the study was to addresses the anode heel effect and off-axis spectra for different target angles. MCNPX has been utilized to simulate the diagnostic x-ray tube with the aim of predicting optimum target angle and angular distribution of x-ray intensity around the x-ray target. For simulation of x-ray spectra, MCNPX was run in photon and electron using default values for PHYS:P and PHYS:E cards to enable full electron and photon transport. The x-ray tube consists of an evacuated 1 mm alumina envelope containing a tungsten anode embedded in a copper part. The envelope is encased in lead shield with an opening window. MCNPX simulations were run for x-ray tube potentials of 70 kV. A monoenergetic electron source at the distance of 2 cm from the anode surface was considered. The electron beam diameter was 0.3 mm striking on the focal spot. In this work, the optimum thickness of tungsten target was $3{\mu}m$ for the 70 kV electron potential. To determine the angle with the highest photon intensity per initial electron striking on the target, the x-ray intensity per initial electron was calculated for different tungsten target angles. The optimum anode angle based only on x-ray beam flatness was 35 degree. It should be mentioned that there is a considerable trade-off between anode angle which determines the focal spot size and geometric penumbra. The optimized thickness of a target material was calculated to maximize the x-ray intensity produced from a tungsten target materials for a 70 keV electron energy. Our results also showed that the anode angle has an influencing effect on heel effect and beam intensity across the beam.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.730-734
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• 1998

Background: It is important to know the location, number, size and shape of bullae before thoracotomy or VATS bullectomy. Chest X-ray and chest CT may be used but with some limitation. The purpose of this study was to compare the diagnostic value of thoracography with that of chest X-ray in preoperative detection of bullae. Meterial and Method: Thoracography was performed by injection of non-ionic water-soluble dye into pleural space in 22 primary spontaneous pneumothoraces, which underwent thoracotomy or VATS bullectomy. Chest X-ray and thoracography were compared through operative finding. Results: Sensitivity and accuracy of thoracography(75% and 72.7%) were higher than those of chest X-ray(30% and 36.4%). However, specificity of thoracography(50%) was lower than that of chest X-ray (100%). There were no complications during or after thoracography. Conclusion: Thoracography is a safer and more useful method for preoperative detection of bullae when compared with chest X-ray.

• Design & Manufacturing
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• v.16 no.4
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• pp.52-59
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• 2022

Currently, Korea is an aging society and is expected to become a super-aged society in about four years. X-ray devices are widely used for early diagnosis in hospitals, and many X-ray technologies are being developed. The development of X-ray device technology is important, but it is also important to increase the reliability of the device through accurate data management. Sensor nodes such as temperature, voltage, and current of the diagnosis device may malfunction or transmit inaccurate data due to various causes such as failure or power outage. Therefore, in this study, the temperature, tube voltage, and tube current data related to each sensor and detection circuit of the diagnostic X-ray imaging device were measured and analyzed. Based on QC data, device failure prediction and diagnosis algorithms were designed and performed. The fault diagnosis algorithm can configure a simulator capable of setting user parameter values, displaying sensor output graphs, and displaying signs of sensor abnormalities, and can check the detection results when each sensor is operating normally and when the sensor is abnormal. It is judged that efficient device management and diagnosis is possible because it monitors abnormal data values (temperature, voltage, current) in real time and automatically diagnoses failures by feeding back the abnormal values detected at each stage. Although this algorithm cannot predict all failures related to temperature, voltage, and current of diagnostic X-ray imaging devices, it can detect temperature rise, bouncing values, device physical limits, input/output values, and radiation-related anomalies. exposure. If a value exceeding the maximum variation value of each data occurs, it is judged that it will be possible to check and respond in preparation for device failure. If a device's sensor fails, unexpected accidents may occur, increasing costs and risks, and regular maintenance cannot cope with all errors or failures. Therefore, since real-time maintenance through continuous data monitoring is possible, reliability improvement, maintenance cost reduction, and efficient management of equipment are expected to be possible.

• Journal of radiological science and technology
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• v.30 no.1
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• pp.53-59
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• 2007

A safety management rule of the diagnosis radiation system which opened a court 2006 February 10th was promulgated for safety of the radiation worker, patients and patients' family members. The purpose of this study is to minimize injury by radiation that can happen to patients and people around a sick ward when managing mobile X-ray system. This study analyzed sickroom environment of mobile X-ray examination and the statistical data of the Konkuk medical Information System(KIS) and the Picture Archiving Communication System(PACS). This study also investigated patient conditions, infection, relation information and related data, when the sickroom mobile X-ray examination is used. Through data analysis, many problems were expected such as restriction of space side, manpower and expense of business side, satisfaction degree decline of patient and protector of operation side. Therefore, we tried to restrict examination of multi bed sickroom, and to use treatment room in each ward to solve problem mentioned. As a result, the whole sickroom mobile X-ray examination rate decreased to near 50%, and mobile X-ray examination rate for inpatients decreased to more than 85%. This study shows that several attempts we did should be helpful for manpower, patients satisfaction and expenses. Also, they should protect patients in sickroom from unnecessary radiation exposure and could minimize inconvenience of patients and their family members from x-ray examination.

• Journal of radiological science and technology
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• v.32 no.1
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• pp.1-15
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• 2009

Newly published IEC 60601-1-3 ; 2008 2nd Edition has two important meanings. First, Radiation Quality and Dose should make sure for safety of patient and staff in manufacturing diagnostic X-ray equipment. Second, it should be minimized of Leakage Radiation, Residual Radiation, and Stray Radiation. The requirement to make enactment or revision of national standard for diagnostic X-ray Equipment is as follows : 1. It should be adjusted the new standard to the recent IEC Publication under the consideration of the Korea medical circumstances. 2. For focus to the Radiation Safety, IEC 60601-1-3 (General requirements for radiation protection in diagnostic X-ray equipment) could be applied to the new regulation. It should be compact sentence. 3. A sudden Notification change should not be desired. It needs a enough time to make easy the circumstances.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.121-121
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• 2002

• Imaging Science in Dentistry
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• v.30 no.3
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• pp.183-188
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• 2000

Purpose: This study was to evaluate the beam quality of intraoral X-ray equipments used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. Materials and Methods : The study was done using the intraoral X -ray equipments used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Results: Most of the HVLs of intraoral X-ray equipments were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANP AS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. Conclusion: HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X -ray equipment should be managed in the planned and organized fashion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.771-772
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• 2010

X-ray equipment used to diagnose a patient has a big defect of a patient's exposure to radiation caused in irradiating X-ray to the human body, ICRP restricts the permissible exposure dose of the human body. A number of studies has been proceeded to reduce these exposures. In this study the high voltage generator with inverter system, which is possible to increase the generation efficiency of X-ray and to control the precise output power was produced. Also, to minimize the ripple which is possible to occur in the direct voltage that is applied to X-ray tube the propagation rectification method was applied and the radiation reproducibility and properties were evaluated to use this for the diagnosis of patient.

• Journal of The Korean Radiological Technologist Association
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• v.25 no.1
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• pp.377-388
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• 1999

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4699-4704
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• 2015

Medical diagnostic X-ray workers are one occupational group that expose to the long-term low-dose external radiation over their working lifetime, and they may under risk of different cancers. This study aims to determine the relationship between the occupational X-ray radiation exposure and cancer risk among these workers in Jiangsu, China. We conducted Nested case-control study to investigate the occupational X-ray radiation exposure and cancer risk. Data were collected through self-administered questionnaire, which includes but not limits to demographic data, personal behaviors and family history of cancer. Retrospective dose reconstruction was conducted to estimate the cumulative doses of the x-ray workers. Inferential statistics, t-test and 2 tests were used to compare the differences between each group. We used the logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of cancer by adjusting the age, gender. All 34 breast cancer cases and 45 esophageal cancer cases that detected in a cohort conducted among health workers between 1950~2011 were included in this presented study, and 158 cancer-free controls were selected by frequency-matched (1:2). Our study found that the occupational radiation exposure was associated with a significantly increased cancer risk compared with the control, especially in breast cancer and esophageal cancer (adjusted OR=2.90, 95% CI: 1.19-7.04 for breast cancer; OR=4.19, 95% CI: 1.87-9.38 for esophageal cancer, and OR=3.43, 95% CI: 1.92-6.12 for total cancer, respectively). The occupational X-ray radiation exposure was associated with increasing cancer risk, which indicates that proper intervention and prevention strategies may be needed in order to bring down the occupational cancer risk.