• Journal of radiological science and technology
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• v.38 no.4
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• pp.395-401
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• 2015

The purpose is to determine the degree of contamination of the equipment for infection control in chest radiography of the radiology department. We confirmed by chemical and bacterial identification of bacteria of the equipment and established a preventive maintenance plan. Chest X-ray radiography contact area on the instrument patients shoulder, hand, chin, chest lateral radiography patient contact areas with a 70% isopropyl alcohol cotton swab were compared to identify the bacteria before and after sterilization on the patient contact area in the chest radiography equipment of the department. The gram positive Staphylococcus was isolated from side shoots handle before disinfection in the chest radiography equipment. For the final identification of antibiotic tested that it was determined by performing the nobobiocin to the sensitive Staphylococcus epidermidis. Chest radiography equipment before disinfecting the handle side of Staphylococcus epidermidis bacteria were detected using a disinfectant should be to prevent hospital infections.

• Journal of Korean Orthopaedic Sports Medicine
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• v.7 no.1
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• pp.50-54
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• 2008

Purpose: In most cases, the main cause of chest or back pain during playing golf is rib fractures. This kind of rib fractures can be easily overlooked in plain radiographs. The purpose of this article is to clarify the value of the ultrasound in detecting rib fractures. Materials and Methods: We compared the findings of chest-X rays (anteroposterior, left or right lateral, both oblique view) with those of the ultrasound in 56 patients between the ages of 20th & 60th who were diagnosed rib fractures. Their chief complaints were chest or back pain which developed during playing golf. The results were analyzed statistically. Results: Among 56 cases of rib fractures, 34 cases were diagnosed with initial X-rays. 51 cases were diagnosed with ultrasound. The sensitivity of radiograph and ultrasound were 60.71% & 91.07%, respectively. Dignosis was ultrasound with statical significance whereas radiography did not(p=0.0004). Conclusion: It was concluded that ultrasound is a valuable tool in the diagnosis of the rib fractures which were undetected with X-rays during playing golf.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.1041-1047
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• 2021

In this study, the effective dose for frequently general radiography among the diagnostic reference level (DRL) for examinations provided by the government in Korea was evaluated using the Monte Carlo N-Particle eXtended (MCNPX) simulation tool. We were selected to evaluate for a total of 5 examination sites which included head anterior-posterior, chest (posterior-anterior, lateral), abdomen anterior-posterior and pelvis anterior-posterior. Physical conditions such as tube voltage and tube current used in MCNPX simulation were used in domestic conditions of the Korea Disease Control and Prevention Agency (KDCA). To evaluate domestic medical radiation exposure, we used the HDRK-Man computerized human phantom manufactured based on the international standard ICRP 103 that was applied to the MCNPX simulation. The phantom could represent the standard body shape of Koreans. As a results, the effective dose corresponding to the DRL based on adult males of head anterior-posterior position was 0.086 mSv, chest posterior-anterior position was 0.05 mSv, chest lateral was 0.354 mSv, abdomen anterior-posterior position was 0.548 mSv, and pelvis anterior-posterior position was 0.451 mSv.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.407-413
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• 2017

Medical radiation offers significant benefits in diagnosing and treating patients, but it also generates unnecessary radiation exposure to those nearby. Accordingly, the objective of the present study was to analyze spatial dose rate according to types of radiation source term in multi-bed hospital rooms occupied by patients and general public. MCNPX was used for geometric simulation of multi-bed hospital rooms and radiation source terms, while the radiation source terms were established as whole body bone scan patients and imaging using a portable X-ray generator. The results of simulation on whole body bone scan patients showed $3.46{\mu}Sv/hr$ to another patient position, while experimental results on imaging using a portable X-ray generator showed $1.47{\times}10^{-8}{\mu}Sv/irradiation$ to another patient position in chest imaging and $2.97{\times}10^{-8}{\mu}Sv/irradiation$ to another patient position in abdomen imaging. Multi-bed hospital room, unnecessary radiation generated in the surrounding patients, while legal regulations and systematic measures are needed for radiation exposure in multi-bed hospital rooms that are currently lacking in Korea.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.139-145
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• 2021

This study is to confirm the range of tube voltage for Chest X-ray in DR system by comparing with dose area product (DAP) and effective dose in efficient detector exposure index (DEI) range. GE definium 8000 was used to for the phantom study. The range of tube voltage is 60~130 kVp and of mAs is 2.5~40 mAs. The acquired images were classified into efficient DEI groups, then calculated effective dose with DAP by using a PC-Based Monte Carlo Program 2.0. The signal to noise ratio (SNR) was measured at 4 regions, including the thoracic spine, the lung area with the ribs, the lung area without the ribs, and the liver by using Picture Archiving and Communication System. The significance of the group for each tube voltage was verified by performing the kruskal-wallis test and the mann-whitney test as a post-test. When set to 4 groups dependned on the tube voltage, DAP showed significant differences; 60 kVp and 80 kVp, and 60 kVp and 90 kVp (p= 0.034, 0.021). Effective dose exhibited no statistically significant differences from the all of the group (p>0.05). SNR exhibited statistically significant differences from the all of the group in the liver except compared to 80 kVp and 90 kVp (p<0.05). Therefore, high tube voltages of 100 kVp or more need to be reconsidered in terms of patient dose and imaging in order to represent an appropriate chest X-ray image in a digital system.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.1049-1056
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• 2021

The purpose of this study was to develop a respiratory synchronization device for X-ray (X-RSD) to increase the reproducibility of inspiration when examining the Chest X-ray of a patient who difficulty in breathing coordination. The X-RSD was self-made using an air pressure sensor and air was injected by connecting a ventilator to the mannequin for CPR. At this time, the amount of injected air was quantified using the SkillReporting device. After placing the X-RSD on the chest of the mannequin, the amount of air was tested in 6 steps from 200 to 700 cc by 100 cc increased. For the accuracy evaluation, the sensitivity of X-RSD was measured by repeating a total of 80 measurements, and the sensitivity was 100%, and very precise results were obtained. After that, the images examined while viewing the X-RSD of the chest lateral examination and the images obtained by the blind examination were compared and evaluated. The lung volume of X-RSD was larger than that of the blind test, and the deviation was smaller. Overall, the use of X-RSD can help with chest X-ray examination of patients who have difficulty in cooperating, and it is thought that it will be possible to contribute to the reduction of exposure dose by reducing the repeat rate of general X-ray examinations.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.903-909
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• 2023

The purpose of this study is to compare and analyze the effect of changes in the patient's central position on the exposure dose and image quality of surrounding organs during a chest lateral examination using an Auto Exposure Control(AEC). The experiment was conducted on a human body phantom. A needle was attached to the lower part of the center of the coronal plane of the phantom, and a lead ruler was attached to the lower part of the detector so that the 50 cm point was located at the lower center of the AEC ion chamber. The exposure conditions were 125 kVp, 320 mA, the distance between the source and the image receptor was 180 cm, and the exposure field size was 14 × 17 inches. Only one AEC ion chamber was used at the bottom center, and the density was set to '0' and sensitivity to 'Middle', and the central X-ray was incident vertically toward the 6th thoracic vertebra. With AEC mode applied, the 50 cm point of the needle and lead ruler were aligned and the phantom was moved 5 cm toward the stomach (F5) and 5 cm toward the back (B5), and the dose factor was analyzed by measuring ESD. The ESD of the thyroid gland according to the change in patient center position was 232.60±2.20 μGy for Center, 231.22±1.53 μGy for F5, and 184.37±1.19 μGy for B5, and the ESD of the breast was 288.54±3.03 μGy for Center, F5 was 260.97±1.93 μGy, B5 was 229.80±1.62 μGy, and the ESD of the center of the lung was 337.02±3.25 μGy for Center, F5 was 336.09±2.29 μGy, and B5 was 261.76±1.68 μGy. As a result of comparing the average values of dose factors between each group, the difference in average values was statistically significant (p<0.01), and each group appeared to be independent. As a result of the study, there was no significant difference in the dose to the thyroid, breast, and center of the lung according to the change in the patient's central position, except for the breast (10%) when the patient moved forward about 5 cm. However, movement of about 5 cm posteriorly resulted in an average dose reduction of 23.7%. Additionally, when the patient's central position was moved to the rear, image quality deteriorated.

• Journal of radiological science and technology
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• v.31 no.4
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• pp.389-399
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• 2008

Corrections of attenuation, scatter and resolution are important in order to improve the accuracy of single photon emission computed tomography (SPECT) image reconstruction. Especially, the heart movement by respiration and beating cause the errors in the corrections. Myocardial phantom is used to verify the correction methods, but there are many different parts in the current phantoms in actual human body. Therefore the results using a phantom are often considered apart from the clinical data. We developed a new phantom that implements the human body structure around the thorax more faithfully. The new phantom has the small mediastinum which can simulate the structure in which the lung adjoins anterior, lateral and apex of myocardium. The container was made of acrylic and water-equivalent material was used for mediastinum. In addition, solidified polyurethane foam in epoxy resin was used for lung. Five different sizes of myocardium were developed for the quantitative gated SPECT (QGS). The septa of all different cardiac phantoms were designed so that they can be located at the same position. The proposed phantom was attached with liver and gallbladder, the adjustment was respectively possible for the height of them. The volumes of five cardiac ventricles were 150.0, 137.3, 83.1, 42.7 and 38.6ml respectively. The SPECT were performed for the new phantom, and the differences between the images were examined after the correction methods were applied. The three-dimensional tomography of myocardium was well reconstructed, and the subjective evaluations were done to show the difference among the various corrections. We developed the new cardiac and torso phantom, and the difference of various corrections was shown on SPECT images and QGS results.

• The Korean Journal of Nuclear Medicine
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• v.34 no.2
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• pp.119-128
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• 2000

Purpose: The aim of this study was to investigate the diagnostic role of $^{99m}Tc$-Tetrofosmin in detection of breast cancer and compared with that of $^{99m}Tc$-MIBI. Material and Methods: Forty-eight patients with a clinically palpable mass or abnormal mammographic or ultrasonographic findings had $^{99m}Tc-MIBI\;and\;^{99m}Tc$-Tetrofosmin scintimammographies after intravenous injection of 925 MBq of radiopharmaceuticals. The scintimammographs were correlated with histopathologic findings. Results: Thirty-three patients were diagnosed with breast cancer and 15 patients with benign breast diseases. The numbers of true positive, true negative, false positive, and false negative cases of $^{99m}Tc$-MIBI scintimammography were 29, 10, 5, and 4 respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of $^{99m}Tc$-MIBI scintimammographies were 87.8%, 66.7%, 85.3%, and 71.4% respectively. The numbers of true positive, true negative, false positive, and false negative cases of $^{99m}Tc$-Tetrofosmin were 31,10, 5, and 2 respectively. The sensitivity, specificity, positive predictive value, negative predictive value of $^{99m}Tc$-Tetrofosmin were 93.9%, 66.7%, 86.1%, and 73.3% respectively. One patient was false negative in both $^{99m}Tc-MIBI\;and\;^{99m}Tc$-Tetrofosmin acintimammographies and its size was 0.5 cm. Conclusion: $^{99m}Tc-Tetrofosmin\;and\;^{99m}Tc-MIBI$ were non-invasive and useful in detection of breast cancer and $^{99m}Tc$-Tetrofosmin was comparable to the $^{99m}Tc$-MIBI in detection of primary breast cancer.