• Journal of radiological science and technology
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• v.23 no.2
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• pp.63-67
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• 2000

The purpose of this study is to survey the present status of portable radiography and the result of free space scattered dose rate when taking a radiography at the general hospital or the university hospital in Taejon city. The results were as follows; 1. The number of cases using portable radiography for three years increased to averages 16.2%, 7.7% per year from January 1st in 1996 to December 31st in 1998. 2. The average of distance of adjacent patients was 219.1 cm at the ward. 3. For portable chest radiography, the free space scattered dose rate was 10.5 mSv/hr at 50 cm distance, 1.8 mSv/hr at 100 cm distance, and 0.2 mSv/hr at 200 cm distance. Therefore, in case of portable chest radiography at the ward, the average of distance of adjacent patients is 219.1 cm, so it does not have influence on the adjacent patients. But during the portable radiography, a guardian who is close to the patient, doctor, nurse and radiologic technologists has to set up the shield to prevent from the unnecessary radiation or the distance should be as great as possible from the mobile X-ray equipment.

• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.200-210
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• 2016

The neutron radiography reactor (NRAD) is a 250 kW Mark-II Training, Research, Isotopes, General Atomics (TRIGA) reactor at Idaho National Laboratory, Idaho Falls, ID, USA. The East Radiography Station (ERS) is one of two neutron beams at the NRAD used for neutron radiography, which sits beneath a large hot cell and is primarily used for neutron radiography of highly radioactive objects. Additional fuel elements were added to the NRAD core in 2013 to increase the excess reactivity of the reactor, and may have changed some characteristics of the neutron beamline. This report discusses characterization of the neutron beamline following the addition of fuel to the NRAD. This work includes determination of the facility category according to the American Society for Testing and Materials (ASTM) standards, and also uses an array of gold foils to determine the neutron beam flux and evaluate the neutron beam profile. The NRAD ERS neutron beam is a Category I neutron radiography facility, the highest possible quality level according to the ASTM. Gold foil activation experiments show that the average neutron flux with length-to-diameter ratio (L/D) = 125 is $5.96{\times}10^6n/cm^2/s$ with a $2{\sigma}$ standard error of $2.90{\times}10^5n/cm^2/s$. The neutron beam profile can be considered flat for qualitative neutron radiographic evaluation purposes. However, the neutron beam profile should be taken into account for quantitative evaluation.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.421-427
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• 2016

We aim to offer basic materials about infection management through conducting bacterial contamination test about general radiography equipment and CT equipment installed in ER of three general hospitals with 100 sickbeds or more located in Gyeongsangbuk-do Province, and suggest management plan. It had been conducted from 1st December 2015 to 31st December, and objects were general radiography equipment and CT equipment of emergency room located in Gyeongsangbuk-do Province. For general radiography equipment, sources were collected from 4 places such as upper side of control box which employees use most, upper side of exposure button, whole upper side of table which is touching part of patient's skin, upper side of stand bucky's grid, and where patients put their jaws on. For CT equipment, sources were collected from 3 places such as upper side of control box which radiography room employees use most, X-ray exposure button, whole upper side of table which is touching part of patient's skin, and gantry inner. Surface contamination strain found at general radiography equipment in emergency room of radiology are Providencia stuartii(25%), Stenotrophomonas maltophilia(18%), Enterobacter cloacae(8%), Pseudomonas species(8%), Staphylococcus epidermidis(8%), Gram negative bacilli(8%), and ungrown bacteria at incubator after 48 hours of incubation (67%) which is the biggest. Most bacteria were found at upper side of stand bucky-grid and stand bucky of radiology's general radiography equipment, and most sources of CT equipment were focused at patient table, which means it is contaminated by patients who have various diseases, and patients who have strains with decreased immunity may get severe diseases. Thus infection prevention should be made through 70% alcohol disinfection at both before test and after test.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.987-994
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• 2019

Low energy x-rays that occur in the low tube voltage radiography of general radiography are absorbed strongly in the body and do not aid image quality enhancement. This study maintains titer in general radiography while using tube current that are proportional to density and the tube voltage 15% principle according to density to reduce patient exposure doses, and area doses and entrance surface doses were measured to compare patient exposure doses. In hand, knee, abdomen, and skull radiography, kVp was increased to 115% and mAs was decreased to 50% and kVp was decreased to 85% while mAs was increased to 200% and area doses and entrance surface doses were measured to compare relative doses. Also, 5 places in each image were set, density was measured, and Kruskal wallis H test was conducted to observe significance probabilities between groups. To fix density, kVp was increased to 115% and mAs was decreased to 50% and after measurements of mean area doses and entrance surface doses were made by each part, each decreased to 58.68% and 59.85% when standard doses were set to 100%, and each increased to 147.28% and 159.9% when kVp was decreased to 85% and mAs was increased to 200%. Comparisons of density changes showed that hand, knee, abdomen, and skull radiography all displayed significance probabilities>0.05, showing no changes in concentration. Radiography that increases kVp and lowers mAs through reasonable calculations within ranges that don't affect resolution and contrast seems to be a simple way to decrease patient exposure doses.

• Journal of The Korean Radiological Technologist Association
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• v.27 no.2
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• pp.22-34
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• 2001

DR은 방사선과 뿐만 아니라 병원전체의 생산성 및 업무의 효율성에서 중요한 요소로 자리잡아가고 있다. DR환경은 CR보다 다양한 Parameter를 가지고 있어 양질의 의료서비스 제공이 가능하다. 현재 각 병원의 방사선과는 Film-Screen system에서 Full-PACS를 통한 DR 환경으로 변화하고 있다. Full- PACS를 사용하고 있는 본원에서는 DR환경에서의 일반촬영 System중 CR과 DDR의 최적노출조건과 그에 따른 Image qu

• Journal of Korean society of Dental Hygiene
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• v.18 no.6
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• pp.1013-1023
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• 2018

Objectives: The purpose of this study is to evaluate dental hygiene students' recognition of safety management and phantom practice in dental radiology. Methods: The study subjects were 409 students in six regions who completed a dental radiology practice course and had on-job experience more than once. After understanding the study purpose and contents, they answered a questionnaire. The main jobs in dental radiology were analyzed. Results: As a result, regarding the most difficult aspects of dental radiology practice, "it is impossible to irradiate the mouth directly with X-rays" was the most common response (29.1%). Regarding the question "what is the main role of students in dental radiology practice?", the answer "it is shooting simulations using phantoms" accounted for 59.7% of responses. The most difficult regions in bisecting and paralleling radiography with a phantom were found to be the maxillary & mandibular molars and premolars. The most difficult technique was reported to be locating XCP maintenance to fit inside the mouth for both molars and premolars. The most difficult region to perform bitewing radiography using the phantom was the molar region (2.87), and the most difficult to perform occlusal radiography approaches were maxillary anterior general occlusal radiography (2.92) and mandibular cross-sectional occlusal radiography (3.00). Conclusions: The most technically difficult point in bitewing and occlusal radiography was the correct positioning of the vertical and horizontal angles. Radiography practice was considered to be more effective than previous mutual practice in terms of analysis of anatomical structures and patient treatment methods. Therefore, it will be necessary to improve policy regarding dental radiography practice at the department of dental hygienics and revise the necessary laws and regulations.

• Journal of the Korean Society of Radiology
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• v.1 no.1
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• pp.31-37
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• 2007

The purpose of this research was to compare and analyze image quality for each Detector of CR(Computed Radiography) and DR(Digital Radiography). The results showed that CR(AGFA MD 4.0 General plate, JAPAN) was superior to DR(HOLOGIC nDirect Ray, USA) based on the quantitative values and comparison of MTF(Modulation Transfer Function), NPS(Noise Power Spectrum), Photon fluence and DQE(Detective Quantum Efficiency) which have been widely accepted for the estimation of CR and DR. Quantitative evaluations of CR and DR system were obtained and they may be very helpful for QA and QC of general X-ray systems.

• Imaging Science in Dentistry
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• v.48 no.3
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• pp.213-221
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• 2018

Purpose: The purpose of this study was to evaluate the relationship between masseter muscle thickness, facial morphology, and mandibular morphology in Korean adults using ultrasonography. Materials and Methods: Ultrasonography was used to measure the masseter muscle thickness bilaterally of 40 adults(20 males, 20 females) and was performed in the relaxed and contracted states. Facial photos and panoramic radiography were used for morphological analyses and evaluated for correlations with masseter muscle thickness. We also evaluated the correlations of age, body weight, stature, and body constitution with masseter muscle thickness. Results: In the relaxing, the masseter was $9.8{\pm}1.3mm$ in females and $11.3{\pm}1.2mm$ in males. In the contracted state, it was $12.4{\pm}1.4mm$ in females and $14.7{\pm}1.4mm$ in males. Facial photography showed that bizygomatic facial width over facial height was correlated with masseter muscle thickness in both sexes in the relaxed state, and was statistically significantly correlated with masseter muscle thickness in males in the contracted state. In panoramic radiography, correlations were found between anterior angle length and posterior angle length and masseter muscle thickness in females, and between body length and posterior angle length, between anterior angle length and body length, between ramal length and body length, and between body length and condyle length in males. Conclusion: Masseter muscle thickness was associated with facial and mandibular morphology in both sexes, and with age in males. Ultrasonography can be used effectively to measure masseter muscle thickness.

• Journal of radiological science and technology
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• v.27 no.3
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• pp.25-29
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• 2004

Among the digital radiography systems, the computed radiography Image Plate Detector System is most frequently being used for the general radiography and also this system commonly diffracts the x-ray images since it is the system that is influenced by the light diffusion from the fluorescent substances. In this study, by using the X-ray Generator, a comparative analysis has been made between 2 different models of computer radiography image plate investigate each model's resolution and sharpness through the modulation transfer function(MTF) measurement. For the analysis, two image plates for general radiography one Fuji ST-VN model(more than 3years old) and one Fuji ST-VL model(less than 2years old) that are currently being used in "Hospital A" were sampled for the MTF measurement here. As the experimental method for this study, the resolution chart method has been carried out by using X-ray generator. Also all the experimental data were printed out by laser printer and measured by microdensitometer. As the results of the experiment carried out in this study, some differences have been found between the two different IP models and Fuji ST-VL has shown its excellence in both of the resolution and the sharpness fields.

• Journal of the Korean Society of Radiology
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• v.5 no.2
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• pp.81-92
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• 2011

This study was carried out to improve service efficiency and to cope with a emergency situation in emergency radiography, through analysis of the radiographic distriution and literature cited about emergency care. Data collection of radiographic distribution was surveyed for 1270 emergency outpatients who visit during JAN, 2009at ER of the general hospital in Gwang city. The results is as follows : Emergency radiography rate of simple radiography was 56.6%, special radiography 2. 5%, CT 34.2%, and ultrasonography 6.7%, In simple radiography rate. a high rate was distributed on male(63.6%), thoracicsurgery part(90.0%), admission patient(77.9%), and long stayed patient at ER. In special raiography rate, a high rate was obsurved in urologic part(28.6%), and in CT rate, observed neurosurgerty part(49.2%) and neurologic part(36.7%). Ultrasonography rate was high for female(8.8%) and internal medicine part(15.9%). There are distributed regional radiography rate in radio-graphic type that chest(55.3%) is high in the simple radiography, urinary system(1.2%) in the special study, and brain(40.0%) in the CT. Regional radiography rate according to diagnostic department also was showed highly for head(64.6%) in neuro surgery, chest(90.0%) in thoracic surgery, abdomen(58.0%) in general surgery, spine(40.0%) in neuro surgery, and pelvis(15.9%), upper extrimity(20.5%), and lower extrimity(31.8%) in orthopedic surgery each. Mean radiographic case number per patient of simple radiography was sinificant on sex, age, transfer relation in both total and radiopraphic patients(p<0.05). Mean radiographic case number was highly distributed on male(2.2 case number) in sex, on thirties(2.7) in age, transferred patient(2.7) in patient type, and on nurosurgery(3.4) in diagnostic charged part. Total radiographic case number in regional party was highly distributed on chest(998 case number.) Considering the above results, emergency radiographer should take care of the elder patient in emergency radiography and get hold of injury mechanism to decrease possible secondary injury during radiography. Because of high radiography rate of urinary system in special study, related instrument. All radiographer who take charge emergency patient should cope with a emergency situation during radiography. Because head trauma patients is very important in patient care, especilly in CT at night, charged doctor should be always sitted with CT room and monitoring patient. Radiography was reqested by many diagnostic department in ER. Considering that rate of simple radiography is high, special room for emergency radiopraphy should be established in ER area, and the radioprapher of this room should be stationed radiologic technician who is career and can implement emergency patient care and The disposition of men which is appropriate with emergency patient increase is necessary.