• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.37-44
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• 2013

In study suggested clinical availability to shoulder forced traction method in term of quality of image, the patient's convenience and stability, according to whether to use of shoulder forced traction bend using computed tomography(CT) that X-ray calibration and various mathematic calibration algorithm application can be applied by AEC. To achieve this, 79 patients is complaining of cervical pain oriented that shoulder forced traction bend use the before and after acquires lateral projection scout image and transverse image. transverse image of a fixed size in concern field of pixel and figure the average HU value compare that quantitative analysis. Artifact and pixel and resolution to qualitative clinical estimation image analysis. the patient feel inconvenience degree that self-diagnosis survey that estimate. As a result, lateral projection scout image if you used shoulder forced traction bend for the depicted has been an increase in the number of a cervical vertebrae. transverse image concern field shoulder forced traction bend use the before and after for pixel and the average HU-value changes was judged to be almost irrelevant. Artifact and resolution and contrast, in qualitative analysis of the results relating the observer to the unusual result. So, the patients of 82.27% complained discomfort that use of shoulder forced traction bend in self-diagnosis survey. No merit of medical image by using of bend from result was analyzed quality of image to quantitative and qualitative method judged. Nowadays, CT is supplied possible revision of quality of radiation by reduction of slice and automatic exposure controller, etc and application of preconditioning filter process due to various mathematic revision algorithm. So, image noise by beam hardening artifact should not be a problem. shoulder forced traction bend of use no longer judged clinically availability because have not influence of image quality and give discomfort, have extra dangerousness.

• Progress in Medical Physics
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• v.17 no.1
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• pp.1-5
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• 2006

A parallel plate detector containing PTFE films in FEP film for relative dosimetry was designed to measure the response of detectors to S and 10 MV X-rays from a medical linear accelerator through different thicknesses of lead. The dielectric materials were 100 m thick. The set-up conditions for measurements with this detector were as follows: SSD=100 cm the test detector was at a depth of 5 cm and the reference chamber was at a depth of 10 cm from the phantom surface for 6 and 10 MV X-rays. Lead blocks were designed to cover the irradiated field. They were added to the tray to increase thickness sequentially. We found that the detector response decreased exponentially with the thickness of lead added. The linear attenuation coefficients of the test detector and reference chamber were 0.1414 and 0.541, respectively, for 6 MV X-rays and 0.1358 and 0.5279 for 10 MV X-rays. The test detector response was greater than that of the reference chamber. The response function was calculated from the measured values of the test detector and reference chamber using optimization. These optimized constants for the detector response function were independent of theenergy. As a result of optimizing the response function between detectors, the use of a relative dosimeter was validated, because the response of the test detector was 1% for 6 MV X-rays and 4% for 10 MV X-rays.

• Radiation Oncology Journal
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• v.23 no.3
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• pp.169-175
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• 2005

Purpose: Although computed tomography (CT) simulators are commonly used in radiation therapy department, many Institution still use conventional CT for treatments. In this study the setup errors that occur during simulation, CT scan (diagnostic CT scanner), and treatment were evaluated for the twenty one breast cancer patients. Materials and Methods: Errors were determined by calculating the differences in isocenter location, SSD, CLD, and locations of surgical clips implanted during surgery. The anatomic structures on simulation film and DRR image were compared to determine the movement of isocenter between simulation and CT scan. The isocetner point determined from the radio-opaque wires placed on patient's surface during CT scan was moved to new position if there was anatomic mismatch between the two images Results: In 7/21 patients, anatomic structures on DRR Image were different from the simulation Image thus new isocenter points were placed for treatment planning. The standard deviations of the diagnostic CT setup errors relative to the simulator setup in lateral, longitudinal, and anterior-posterior directions were 2.3, 1.6, and 1.6 mm, respectively. The average variation and standard deviation of SSD from AP field were 1.9 mm and 2.3 mm and from tangential fields were 2.8 mm and 3.7 mm. The variation of the CLD for the 21 patients ranged from 0 to 6 mm between simulation and DRR and 0 to 5 mm between simulation and treatment. The group systematic errors analyzed based on clip locations were 1.7 mm in lateral direction, 2.1 mm in AP direction, and 1.7 mm in SI direction. Conclusion: These results represent that there was no significant differences when SSD, CLD, clips' locations and isocenter locations were considered. Therefore, it is concluded that when a diagnostic CT scanner is used to acquire an image, the set-up variation is acceptable compared to using CT simulator for the treatment of breast cancer. However, the patient has to be positioned with care during CT scan in order to reduce the setup error between simulation and CT scan.

• Journal of Preventive Medicine and Public Health
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• v.29 no.4 s.55
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• pp.877-897
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• 1996

In recent years, the Korean Medical Association has undertaken the feat of establishing the Korean Standard Terminology of Medical Procedures with the dedicated help of 32 medical academic societies. However, because the project is being conducted by several different circles, it has yet to see a clear system of classification. This thesis, therefore, proposes the three principles of scientific properties, usefulness and ideology as the basis for classification system and has developed the Classification System of Medical Procedures in Korea upon their foundation. The methodology and organization of this thesis as follows. First, by adopting scientific classification system of Feinstein(1988), an analysis of the classification systems of the medical procedures in the United States, Japan, Taiwan, WHO was carried out to reveal the framework and the basic principles in each system. Second, the direction of classification system has been constructed by applying the normative principle of medical field in order to show the future direction of the medical field and realize its ideology. Third, a finalized framework for the classification system will be presented as based on the direction of classification system. Of the three basis principles mentioned above, the analysis on the principles of usefulness was left out of this thesis due to the difficulty of establishing specific standards of analysis. The results of the study are as follows. The overall structure of the thesis is aimed at showing the 'Prevention-Therapy-Rehabilitation' quality of comprehensive health care and consists of six chapters; I. Prevention and Health Promotion II. Evaluation and Management III. Diagnostic Procedures IV. Endoscopy V. Therapeutic Procedures VI. Rehabilitation Chapter three Diagnostic Procedures is divided into four parts : Functional Diagnosis, Visual Diagnosis, Pathological Diagnosis, Biopsy and Sampling. Chapter five Therapeutic Procedures is divided into Psychiatry, Non-Invasive Therapy, Invasive Therapy, Anaesthesia and Radiation Oncology. Of these sub-divisions, Functional Diagnosis, Biopsy and Sampling, Endoscopy and Invasive Therapy employs the anatomical system of classification. On the other hand, Visual Diagnosis, Pathological Diagnosis, Anesthesia and Diagnostic Radiology, namely those divisions in which there is little or no overlapping in services with other divisions, used the classification system of its own division. The classification system introduced in this thesis can be further supplemented through the use of the cluster analysis by incorporating the advice and assistance of other specialists.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.1
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• pp.8-16
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• 1981

A mathematical model based on the water flow equation was developed with the Ohm's analogy and the partial differential equations. Simulation of water uptake was performed by numerically solving the equations with the aid of a differential equation solver, DGEAR in IMSL package, in FORTRAN version. The input data necessary were climatological parameters (temperature, solar radiation, humidity and wind speed). plant parametors (leaf water potential, leaf area, root conductivity and root length density) and soil parameters (hydraulic conductivity and The graphical comparison of the simulated and measured water contents as the functions of time showed good agreement, but there still was some disparity due to possible inacouracy of the field measured parameters. The simulated soil evaporation showed about 2 mm/day early in the growing period and dropped to about 0.4 mm/day as the full canopy developed and the soil water depleted. During the dry period, soil evaporation was as low as 0.1 mm/day. The transpiration was as high as 5mm/day. Deep percolation calculated from the flux between the 180-cm layer was about 0.2mm/day and became smaller with time. After the soil water of upper layers depleted, the flux reversed showing capillary rise. The rate of the capillary rise reached about 0.07mm/day, which was too low to satisfy water uptake of the root system. Therefore, to increase use of water in deep soil, expansion of the root system is necessary.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.411-416
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• 2023

The purpose of this study is to investigate the utilization of major learning tools among radiology science students and assess the accuracy of a conversational artificial intelligence service program, specifically a chatbot, in the context of the national radiologic technologist licensing exam. The survey revealed that 84.3% of radiology science students actively utilize electronic devices during their learning process. In addition, 104 out of 140 respondents said they use search engines as a top priority for efficient data collection while studying. When asked about their awareness of chatbots, 80% of participants responded affirmatively, and 22.9% reported having used chatbots for academic purposes at least once. From 2018 to 2022, exam questions from the first and second periods were presented to the chatbot for answers. The results showed that ChatGPT's accuracy in answering first period questions increased from 48.28% to 60%, while for second period questions, it increased from 50% to 62.22%. Bing's accuracy in answering first period questions improved from 55% to 64.55%, and for second period questions, it increased from 48% to 52.22%. The study confirmed the general trend of radiology science students utilizing electronic devices for learning and obtaining information through the internet. However, conversational artificial intelligence service programs in the field of radiation science face challenges related to accuracy and reliability, and providing perfect solutions remains difficult, highlighting the need for continuous development and improvement.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.490-499
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• 2002

Recently, gamma radiographic equipments have been used about 1,000 sets manually and operated by about 2,500 persons in Korea. In order for a radiography to work effectively with avoiding any hazard of the high level radiation from the source, many field workers have expected developing a wireless automatic remote exposure controller. The KlTCO research team has developed an automatic remote exposure controller that can regulate the speed of $0.4{\sim}1.2m/s$ by BLDC motor of 24V 200W which has output of $54kgf{\cdot}cm$, suitable torque and safety factor for the work. And the developed automatic remote exposure controller can control rpm of motor, pigtail position by photo-sensor and exposure time by timer to RF sensor. Thus, the developed equipment is expected that the unit can be used in many practical applications with benefits in economical advantage to combine the use of both automatic and manual type because attachment is possible existent manual remote exposure controller, AC and DC combined use.

• Progress in Medical Physics
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• v.9 no.4
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• pp.267-276
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• 1998

Any detector inserted into a phantom should have such a geometry that it caused as small as possible perturbation of the electron fluence. Plane parallel chambers meet this requirement better than other chambers of configurations. IAEA protocol recommends the use of plane parallel chambers for this reason. However, the cylindrical chambers are widely used for convenient. The purpose of this study is to evaluate the absorbed dose due to the differences of four different dosimetry protocols such as IAEA protocol using cylindrical chamber, TG 21 protocol using cylindrical chamber, Markus protocol using plane parallel chamber, and TG 39 report for the calibration of plane parallel chamber in electron beams. Depth-ionization measurements for the electron beams of nominal energy 6, 9, 12, 15, and 18 MeV from Siemens accelerator with a 10$\times$10 cm$^2$ field size were made using a radiation field analyser with 0.125 cc ion chamber. Dosimetric measurements by IAEA and TG 21 protocol were made with a farmer type ionization chamber in solid water for each electron energy, respectively. Dosimetric measurements by Markus protocol were made with a plane parallel ionization chamber in solid water for each electron energy, respectively. The cavity-gas calibration factor for the plane parallel chamber was obtained with the use of 18 MeV electron beam as guided by TG 39 report. Dosimetric measurements by TG 39 were performed with a plane parallel ionization chamber in solid water for each electron energy, respectively. For all the energies and protocols, measurements were made along the central axis of the distance of 100 cm (SSD = 100 cm) with 10$\times$10 cm$^2$ field size at the depth of d$_{max}$ for each electron beam, respectively. In the case of 18 MeV, the discrepancy of 0.9 % between IAEA and TG 21 was found and the two protocols were agreed within 0.7 % for other energies. In the case of 18 MeV and 6 MeV, the discrepancies of $\pm$ 0.8 % between Markus and TG 39 was found, respectively and the two protocols were agreed within 0.5 % for other energies. Since the discrepancy of 1.6 % between cylindrical and plane parallel chamber was found for 18 MeV, it is suggested to get the calibration factor using other method as guided. by TG 39.9.

• Journal of radiological science and technology
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• v.35 no.4
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• pp.335-343
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• 2012

Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photonueutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photonbeams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the phtoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the phtoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose.

• Progress in Medical Physics
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• v.23 no.4
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• pp.279-284
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• 2012

The X ray has been widely used in both diagnosis and treatment. Recently, a miniature X ray tube has been developed for radiotherapy. The miniature X ray tube is directly inserted into the body irradiated, so that X rays can be guided to a target at various incident angles according to collimator geometry and, thus, minimize patient dose. If such features of the miniature X ray tube can be applied to development of X ray imaging as well as radiation treatment, it is expected to open a new chapter in the field of diagnostic X ray. However, the miniature X ray tube requires an added filter and a collimator for diagnostic purpose because it was designed for radiotherapy. Therefore, a collimator and an added filter were manufactured for the miniature X ray tube, and mounted on. In this study, we evaluated beam characteristics of the miniature X ray tube for diagnostic X ray system and accuracy of measuring the HVL. We used the Si PIN Photodiode type Piranha detector (Piranha, RTI, Sweden) and estimated the HVL of the miniature X ray tube with added filter and without added filter. Through an another measurement using Al filter, we evaluated the accuracy of the HVL obtained from a direct measurement using the automatic HVL calculation function provided by the Piranha detector. As a result, the HVL of the miniature X ray tube was increased around 1.9 times with the added filter mounted on. So we demonstrated that the HVL was suitable for diagnostic X ray system. In the case that the added filter was not mounted on, the HVL obtained from use of the automatic HVL calculation function provided by Piranha detector was 50% higher than the HVL estimated using Al filter. Therefore, the HVL automatic measurement from the Piranha detector cannot be used for the HVL calculation. However, when the added filter was mounted on, the HVL automatic measurement value using the Piranha detector was approximately 15% lower than the estimated value using Al filter. It implies that the HVL automatic measurement can be used to estimate the HVL of the miniature X ray tube with the added filter mounted on without a more complicated measurement method using Al filter. It is expected that the automatic HVL measurement provided by the Piranha detector enables to make kV-X ray characterization easier.