• Proceedings of the Korean Society of Medical Physics Conference
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• 한국의학물리학회 1999년도 Japanese Journal of Medical Physics
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• pp.289-291
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• 1999

• Journal of Chest Surgery
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• 제22권2호
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• pp.321-324
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• 1989

The Swyer-James syndrome is rare abnormality that may be encountered on routine chest X * ray examination and frequently presents a diagnostic problem. Recently, we experienced a case of Swyer-James syndrome which was accompanied with ipsilateral uncontrolled pneumothorax. We performed exploratory thoracotomy because of failure of re-expansion of the lung. Right pneumonectomy was performed and postoperative course was uneventful.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.836-845
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• 2017

Gravimetric method is usually used to evaluate air-dry density, which is governing physical or mechanical properties of wood. Although it had high evaluation accuracy, the method is time consuming process. Thus, this study was conducted to estimate air-dry density of wood with high accuracy by using polychromatic X-ray and digital detector as alternative of gravimetric method. To quantify polychromatic X-ray projection for evaluating air-dry density, Lambert-Beer's law with the integral value of probability function was used. The integral value was used as weighting factor in the law, and it was determined by conducting simple test at various penetration depths and tube voltage. Mass attenuation coefficient (MAC) of wood also calculated by investigating polychromatic X-ray projection according to species, penetration depth and tube voltage. The species had not an effect on change of MAC. Finally, an air-dry density of wood was estimated by applying the integral value, MAC and Lambert-Beer's law to polychromatic X-ray projection. As an example, the relation of the integral value (${\alpha}$) according to penetration depth (t, cm) at tube voltage of 35 kV was ${\alpha}=-0.00091t{\times}0.0184$ while the regression of the MAC (${\mu}$, $cm^2/g$) was ${\mu}=0.5414{\exp}(-0.0734t)$. When calculation of root mean squared error (RMSE) was performed to check the estimation accuracy, RMSE at 35, 45 and 55 kV was 0.010, 0.013 and $0.009g/cm^3$, respectively. However, partial RMSE in relation to air-dry density was varied according to tube voltage. The partial RMSE below air-dry density of $0.41g/cm^3$ was $0.008g/cm^3$ when tube voltage of 35 kV was used. Meanwhile, the partial RMSE above air-dry density of $0.41g/cm^3$ decreased as tube voltage increased. It was conclude that the accuracy of estimation with polychromatic X-ray and digital detector was quite high if the integral value and MAC of wood were determined precisely or a condition of examination was chosen properly. It was seemed that the estimation of air-dry density by using polychromatic X-ray system can supplant the gravimetric method.

• Journal of the Korean Society of Radiology
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• 제11권1호
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• pp.37-42
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• 2017

We measured the absorbed dose and the area dose using an ionization chamber type of area dose product (DAP) meter and measured the calibration factor in the X-ray examination. In the indirect dose measurement method, the detector was installed in the radiation part of the X-ray equipment, and the measured value was calculated as the dose at the exposure part. The instrument used to calculate the calibration factor was an X-ray equipment (DK-550R / F, DongKang Medical Co., Ltd., Seoul, Korea). The calibration method for the calibration factor was to connect the DAP meter (PD-8100, Toreck Co. Ltd., Japan) to the calibration dosimeter tube voltage of 70 kV, tube current of 500 mA, 0.158 sec. The reference dosimeter used a semiconductor (DOSIMAX plus A, Scanditronix, $Wellh{\ddot{o}}fer$, Germany). After installing the DAP meter on the front of the multi-collimator of the ionization chamber, the calibration factor of the dosimeter was obtained using the reference dosimeter for accurate dose measurement. Experimental exposure values and values from the calibration dosimeter were calculated by multiplying each calibration factor. The calibration factor was calculated as 1.045. In order to calculate the calibration coefficient according to the tube voltage in the ionization type DAP dosimeter, the absorbed dose and the area dose were calculated and the calibration factor was calculated. The corrective area dose was calculated by calculating the calibration factor of the DAP meter.

• Tuberculosis and Respiratory Diseases
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• 제43권1호
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• pp.113-116
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• 1996

A previously healthy 59-year old male patient was admitted due to cough and abnormal chest x-ray. Cough started 5 months ago and persisted. Two months before admission, abnormality in chest PA was detected. He had no symptom other than cough. He was nonsmoker and physical examination revealed no abnormal finding. His chest X-ray showed ill-defined $2{\times}1\;cm$ ovoid infiltration in left middle lung field. On chest computed tomography, it was located in the subpleural region of posterobasal segment of left lower lobe. Mediastinal lymphadenopathy was absent. Blood test and sputum examination were not diagnostic. Fluoroscopy-guided percutaneous needle biopsy revealed pulmonary cryptococcosis. After central nervous system involvement was excluded by spinal tap, oral ketoconazole therapy was started. The lesion decreased in size after 8 weeks of therapy and almost disappeared on follow-up chest X-ray 4 months later.

• Journal of radiological science and technology
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• 제47권3호
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• pp.197-203
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• 2024

During paranasal sinus X-ray examinations in children, the radiological technologist's thyroid shield is often not implemented to shorten the examination time. This study measured the radiation exposure before and after the implementation of thyroid shielding by analyzing the difference in radiation exposure, the radiological technologist's could receive depending on the actual thyroid shielding. In the left TLD, when thyroid shielding was not performed(N), the radiation exposure dose(mSv) was 2.869 for the depth dose[Hp(10)] and 2.886 for the surface dose[H(3)], and when thyroid shielding was performed(Y), the Hp(10) was 0.033 and the H(3) was 0.034. In the right TLD, when thyroid shielding was not performed(N), the radiation exposure dose was 3.149 for Hp(10) and 3.137 for H(3), and when thyroid shielding was performed, the Hp(10) of (Y) was 0.013 and the H(3) was 0.015. The differences in the overall exposure dose measurement values are all statistically significant (p<0.05). The difference in radiation dose between when thyroid shielding was not performed and when thyroid shielding was performed was more than 99.2% in both cases, indicating a high radiation shielding rate.

• Journal of radiological science and technology
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• 제45권4호
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• pp.299-304
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• 2022

This study uses the 'S-align' function to present a reference value of the X-ray tube angle for the realization of an image similar to that of the chest PA image during chest AP radiography. This study targeted dummy phantom and used a 17"×17" DR image receptor. The irradiation conditions were 110 kVp, 160 mA, 50 ms, and the distance between the central X-ray and the image receptor was set to 180 cm and 110 cm, respectively. The end of the catheter was placed at the 11th thoracic height to indicate the nasogastric tube. In the case of lung apex length measurement, the mean value of measurement was 30.53±0.47 in PA. T 0°, TCA 5~25°, TCE 5~15° were 21.07±0.29, 27.60±0.21, 34.13±0.44, 39.86±0.31, 45.96±0.61 mm, 54.13±0.37 mm, 16.16±0.46 mm, 9.81±0.35 mm, 2.75±0.30 mm, respectively. For the depth of the catheter end, the average value measured at PA was 6.70±0.31 mm. T 0°, TCA 5~25°, TCE 5~15° were 15.72±0.38 mm, 24.10±0.50 mm, 29.24±0.86 mm, 34.35±0.35 mm, 41.06±1.08 mm, 48.07±0.38 mm, 12.85±0.25 mm, 7.92±0.36 mm, 3.01±0.39 mm, respectively. The length of the lung apex was similar to that of chest PA when the angle of incidence was adjusted from 5° to 10° in the leg direction, and the depth of the catheter tip was most similar when the X-ray tube angle was incident at 10° in the head direction. Therefore, To change the X-ray tube angle according to the purpose of the examination during the chest AP radiography using 'S-align' function is considered necessary.

• Journal of Chest Surgery
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• 제9권1호
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• pp.69-72
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• 1976

This is to report a case of bronchgenic cyst. While most of the bronchogenic cysts reported in the literature so far were located either in the lung parechym or in the mediastinum near the tracheal bifurcation or main bronchi. the cyst presenting in this study was originated in the wall of the esophagus and was reported to be very rare. The cystic tumor was found accidentally by X-ray fluoroscopic examination of the esophagus and stomach in the patient with gastric hemorrhage. X-ray study revealed that the cystic tumor was oval in shape and located in the left posterolateral wall of the esophagus in the thoracic lower third. Two surgical operations, gastrectomy for gastric hemorrhage and the resection of the cystic tumor, were carried out separately. Gastrectomy including the removal of prepyloric ulcer by the Billroth II type procedure was performed in regular fashion, and the cystic tumor was resected radically without any injury of the mucous membrane of the esophagus. The cyst removed appeared to be filled with mucinous material, and histological examination identified the tumor as a bronchogenic cyst with ciliated epithelial internal lining. Postperative course of the patient was uneventful.

• Journal of radiological science and technology
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• 제20권1호
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• pp.39-42
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• 1997

This study was done at 45 medical facilities located in Seoul. The purpose of study is twofold. First, this is to investigate usually who extmines patients for UGI and how many films are used for the examination. Secondly, this is to evaluate image qualities of UGI in terms of representation of lesser curvatures, amount of Ba and air and other criteria for the exam. The results are as follows : 1. In most cases, the UGI is examined by the Dr(67%), by the RT(22%), and together(11%). 2. The total films used ranged from 5 sheets(42%) to 7 sheets(18%). 3. The amount of Ba given to Pt. was mostly $200{\sim}300\;ml$(60%) and gastrografin was used $3{\sim}4\;g$(86.6%) for the examination. 4. For the evaluation of qualities, lack of representation of lesser curvature was 86.7%, lack of Ba and air and bubble formation was 62%, 46.7% and 42.2% respectively.

• Korean Journal of Veterinary Research
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• 제60권3호
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• pp.145-153
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• 2020

This study aimed to evaluate the effects of a bioabsorbable bone hemostatic agent comprising poly (ethylene glycol-propylene glycol) copolymers (PEG-PPG) on hemostasis and osteogenesis. Bilateral 3 mm diameter calvarial defects were created in 99 male Sprague-Dawley rats. The defects were filled with PEG-PPG or bone wax. The defects of control group were left unfilled. Virtual autopsy was performed to evaluate bioabsorption. The calvaria were subjected to x-ray microtomography (microCT) and histological examination. Bone volume fraction (BV/TV) and bone mineral density (BMD) were measured using microCT; furthermore, white blood cell count and histological examination were performed. After application of PEG-PPG and bone wax, immediate hemostasis was achieved. Autopsy revealed that PEG-PPG disappeared within 48 h at the application site; in contrast, bone wax remained until 12 weeks. The PEG-PPG and control groups showed significantly more osteogenesis than the bone wax group with respect to BV/TV and BMD at 3, 6, and 12 weeks (p < 0.05). Histology revealed that the bone wax group exhibited little bone formation with inflammation. In contrast, PEG-PPG and control groups showed significantly more qualitative osteogenesis than the bone wax group (p < 0.01). In conclusion, PEG-PPG showed immediate hemostasis and was absorbed to allow progressive osteogenesis.