• Journal of radiological science and technology
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• v.21 no.1
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• pp.52-58
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• 1998

We can and must improve the diagnostic images using available knowledge and technology. At the same time we must strive to reduce the patient's integral and entrance radiation dose. Reducing the integral dose to the patient during the radiologic procedure is a primary concern of the patient, especially the pediatric patient, the radiologist and the technologist. A 100cm focal film distance generally is used for most over-table radiography. The early x-ray tubes and screen film combinations required long exposures, which often resulted in motion artifacts. But nowaday, we have the generators and x-ray tubes that can deliver the energy necessary in a very short time and the receptors that can record the information just as rapidly. And, we performed this studies to evaluate the patient exposure dose and the image quality by increasing focal film distance in diagnostic radiography. There are many factors which affected to exposure factor, but we studied to verify of FFD increase, only. Effect of increasing the focal film distance to a 140 cm distance was tested as follows; 1. The focal film distances were set at 100, 120, and 140cm. 2. A 18cm acryl(tissue equivalent) phantom was placed on the table top. 3. An Capintec 192 electrometer with PM 05 ion chamber was placed at the entrance surface of the phantom, and exposure were made at each focal film distances. 4. The procedure was repeated in the same manner as above except the ion chamber was placed beneath the phantom at the film plane. 5. Exit exposure were normalize to 8mR for each portions of the experiment. Based on the success of the empirical measurements, a detailed mathematical analysis of the dose reduction was performed using the percent depth dose data. The results of this study can be summerized as followings ; 1) Increasing FFD from 100 cm to 140 cm, we would create a situation that would have a significant effect on the overall quality of radiograph and achive the 17.42% reduction of entrance dose and the 18.95% reduction of integral dose that the patient receives. 2) Thickness of Al step wedge for equal film density increased with the long distance. 3) Increasing FFD, Magnification of image was lowered. 4) Resolution of image also increased with the FFD. As the results described above, we strongly recommend using the long FFD to provide better information for our patients and profession in abdomen radiographic studies.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.481-487
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• 2019

Based on the scan conditions and algorithms that are generally applied during examinations during head CT examinations, the results of dose reduction through the application of algorithm changes were investigated through experiments. As a result, the dose reduction effect was more meaningful for the change of perfusion than for the tube voltage, and the quality evaluation using the brain phantom was relatively less reduced when the dose was reduced after the application of the Bone algorithm, especially for the application of the Bone algorithm, and the deviation of the mean CT number or Pixel value was measured relatively significantly. In other words, the conditions under which dose was reduced and quality was maintained to reduce the patient's exposure dose and obtain images of the same quality were obtained with the application of the Smooth algorithm and the resulting values of 120 kVp, 160 mA. At this point, doses were reduced by about 28%, and the mean CT number or Pixel value was also measured with relatively little error. If the results are applied to patients who visit the hospital for examination or follow-up after applying various algorithms and follow up scan conditions, the results are considered to be very useful in reducing patient exposure dose.

• Archives of Craniofacial Surgery
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• v.14 no.2
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• pp.81-88
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• 2013

Background: To suggest the need of more aggressive reduction techniques than closed reduction (CR) technique in nasal fracture treatment, we identified the usefulness of algorithm oriented treatment of nasal fracture that includes indirect open reduction (IOR) and external fixation (EF) as well as the CR. Methods: We compared the clinical course of the group A (n=128) where only the CR was performed regardless of the pattern of the nasal fracture and the group B (n=127) where algorithm oriented treatment including IOR and EF as well as CR was performed depending on the pattern of nasal fracture. And the degree of postoperative pain after CR and IOR technique was compared through the dose of analgesics and pain scores. Results: More than 80% of patients were satisfied the result of reduction in both group A and B. Good contour of nasal bone after reduction was showed 71% of group A and 81% of group B without significant difference. Minor (p>0.05) and major (p<0.05) deformity after reduction were less occurred in the group B than group A. Postoperatively, the dose of analgesics was significantly lower after IOR technique than CR technique (53 mg vs. 142 mg) (p<0.05). Conclusion: Algorithm oriented treatment of nasal fracture including IOR and EF as well as CR reduce major deformity after reduction than treatment of CR alone. It is useful to perform the more aggressive reduction techniques such as IOR and EF according to the pattern of fracture in treatment of nasal fracture.

• Progress in Medical Physics
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• v.27 no.4
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• pp.241-249
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• 2016

The present study used a digital angiography x-ray device to measure the space dose and exposure dose of patients and practitioners using x-ray tube shielding devices developed in our laboratory. The intent of the study was to reduce the space dose within the test room, and to reduce the exposure dose of patients and practitioners. The patient and practitioner exposure doses were measured in five configurations in a human body model. The glass dosimeter was placed on the eye lenses, thyroid glands, left shoulder, right shoulder, and gonads. The beam was collimated at full size and at a 48% reduction for a comparative analysis of the measurements. The space dose was measured with an ion chamber at distances of 50 cm, 100 cm, and 150 cm from the x-ray tube under the following conditions: no shielding device; a shielding device made of 3-mm-thick lead (Pb) [Pb 3 mm shield], and a shielding device made of 3-mm-thick Pb (outside) and 3-mm-thick aluminum (Al) (inside) [Pb 3 mm＋Al 3 mm shield]. The absorbed dose was the lowest when the 3-mm-thick Pb＋3-mm-thick Al shield was used. For measurements made with collimated beams with a 48% reduction, the dose was the lowest at $154{\mu}Gy$ when the 3-mm-thick Pb＋3-mm-thick Al shield was used, and was $9{\mu}Gy$ lower than the measurements made with no shielding device. If the space dose can be reduced by 20% in all situations where the C-arm is employed by using the x-ray tube shielding devices developed in our laboratory, this is expected to play an important role in reducing the annual exposure dose for patients, practitioners, and assistants.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.1
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• pp.24-30
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• 2011

The anti-cancer effects of Angelica keiskei ethanol extract were evaluated in human breast cancer MDA-MB-231 cells. The concentrations of extract were 1, 2, 3, 4 and 5 mg/mL. Dose-dependent reductions in the number of cells with altered cell shape and pyknotic nuclei were observed at 48 h after treatments. MTT assay also exhibited a similar dose-dependent reduction in mitochondrial reductase activity (p<0.05), in particular, with a rapid reduction in the activity of the 5 mg/mL group. Analysis of cell death with propidium iodide (PI) staining revealed only a slight increase in cell death in the 5 mg/mL group. Analysis of bromodeoxyuridine (BrdU) incorporations also showed a dose-dependent reduction in cell proliferation (p<0.05). Finally, increases in total radical oxygen species (ROS) accumulation in cells, as revealed by DCF-DA staining, were observed in the treated groups in a similar dose-dependent fashion (p<0.05). These results indicate that Angelica keiskei ethanol extract exhibiting anti-cancer effects in MDA-MB-231 cells causes multiple changes in cell shape, enzyme activity, and ROS accumulation, thereby inducing cell death.

• Journal of radiological science and technology
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• v.37 no.1
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• pp.21-28
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• 2014

Cultured pancreatic beta cells and nerve cells, it is given normal condition of 10% FBS (fetal bovine serum), 11.1 mM glucose and hyperglycemia codition of 1% FBS, 30 mM glucose. For low LET X-ray irradiated with 0.5 Gy/hr dose-rate(total dose: 0.5 to 5 Gy). Survival rates were measured by MTT assay. When non irradiated, differentiated in the pancreatic beta cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a small reduction. However increasing the total dose of X-ray, the survival rate of normal conditions decreased slightly compared to the survival rate of hyperglycemia conditions, the synergistic effect was drastically reduced. When non irradiated, undifferentiated in the nerve cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a large reduction. As the cumulative dose of X-ray normal conditions and hyperglycemia were all relatively rapid cell death. But the rate of decreased survivals by almost parallel to the reduction proceed and it didn't show synergistic effect.

• Preventive Nutrition and Food Science
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• v.22 no.1
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• pp.45-49
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• 2017

The anti-obesity effects of yeast hydrolysate (YH) supplementation (1.0 g/d) have already been demonstrated. We investigated whether a low dose of YH (0.5 g/d, YH-500) also has the anti-obesity effects. Thirty obese women were randomly assigned to the control or YH-500 groups. After 8 weeks, weight and body mass index were significantly reduced by the YH treatment (0.5 g/d) (P<0.05). The YH-500 group lost a significant amount of body fat after the 8-week treatment: fat mass 25.9 kg (baseline) versus 23.8 kg (8th week), P<0.01; fat mass ratio 38.8% (baseline) versus 36.5% (8th week), P<0.05. The YH-500 group showed a significant reduction in calorie intake during the 8-week treatment (P<0.001). The control group wanted to eat much more food (P<0.05) and sometimes thought about eating more often compared with the YH-500 group (P<0.05). Whereas the control group showed a slightly increased sweet preference, the YH-500 group showed a significant reduction in sweet preference (P<0.05). In conclusion, low dose YH supplementation (0.5 g/d) may induce a reductions in weight and body fat in obese women via the reduction of calorie intake.

• Journal of Periodontal and Implant Science
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• v.27 no.4
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• pp.701-722
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• 1997

It was reported that low dose doxycycline(LDD) regimen could inhibit pathologically elevated collagenase activity in the gingival crevicular fluid of petients with adult periodontitis without producing typical antibiotic side effects. The purpose of this study was to evaluate the effects of LDD regimen(20mg) administered during non-surgical therapy on clinical index and gingival crevicular fluid enzyme activity in diabetics who are at high risk for periodontal disease. Forty-nine subjects having at least two sites with probing pocket depths greater than 4mm were selected. In this double-blind, placebo-controlled study, the patients were administered 20 mg doxycycline capsule or placebo capsule b.i.d. for 2 weeks. Clinical parameters of dental plaque, gingival inflammation, probing pocket depth and probing attachment level were assessed at week 0, 2, 4, and 8. Gingival crevicular fluid samples were collected at the same time to evaluate the activities of collagenase and elastase. Clinical parameters and elastase activity were significantly reduced in all groups compared to the baseline value after treatment. Significantly greater reduction in pocket depth and gain in attachment level was shown in the LDD-administered group compared to placebo group in both adult periodontitis and diabetic patients. Total collagenase activity was also reduced significantly in all groups after treatment, but the greater reduction was seen in the LDD-administered diabetics group compared to relevant placebo group(at 4, 8week). Significantly greater reduction in active collagenase activity was also seen in the LDD-administered group compared to placebo group in diabetic patients(at 2, 4, 8week). These results indicated that use of low dose doxycycline could be aueseful adjunct to instrumentation therapy in the management of diabetic patient with periodontitis as well as adult periodontitis patient.

• Progress in Medical Physics
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• v.16 no.3
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• pp.138-147
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• 2005

The Monte Carlo method cannot have been used for routine treatment planning because of heavy time consumption for the acceptable accuracy. Since calculation time is proportional to particle histories, we can save time by decreasing the number of histories. However, a small number of histories can cause serious uncertainties. In this study, we proposed Monte Carlo dose computation time and uncertainty reduction method using specially designed filters and adaptive denoising process. Proposed algorithm was applied to 6 MV photon and 21 MeV electron dose calculations in homogeneous and heterogeneous phantoms. Filtering time was negligible comparing to Monte Carlo simulation time. The accuracy was improved dramatically in all situations and the simulation of 1 $\%$ to 10$\%$ number of histories of benchmark in photon and electron dose calculation showed the most beneficial result. The empirical reduction of necessary histories was about a factor of ten to fifty from the result.

• Journal of radiological science and technology
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• v.43 no.5
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• pp.353-357
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• 2020

IVR procedures are on the rise, and patient doses are on the rise. It is necessary to evaluate fluoroscopy dose in IVR procedure. Evaluate ESD on IVR equipment as a reference to DRL settings, I would like to present the direction of improvement in the ESD rate test criteria for fluoroscopy dose. The experimental method is measured with 6cc ionization chamber under the 20cm PMMA Phantom. Radiation is subject to abdominal procedure. The average dose rate of the incident surface was 21.6 ± 11.4 mGy/min. The highest dose equipment was 58.5 mGy/min, and there was no equipment exceeding the domestic standard of 100 mGy/min. However, there were five units above 50 mGy/min. To reduce fluoroscopy dose, it is recommended to reduce pulse rate, The dose increases as the image receptor ages. It is recommended to modify the domestic inspection criteria to 50 mGy/min.