• Title/Summary/Keyword: Radiology science department

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Variation Analysis of Distance and Exposure Dose in Radiation Control Area and Monitoring Area according to the Thickness of Radiation Protection Tool Using the Calculation Model: Non-Destructive Test Field (계산 모델을 활용한 방사선방어용 도구 두께에 따른 방사선관리구역 및 감시구역의 거리 및 피폭선량 변화 분석 : 방사선투과검사 분야 중심으로)

  • Gwon, Da Yeong;Park, Chan-hee;Kim, Hye Jin;Kim, Yongmin
    • Journal of the Korean Society of Radiology
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    • v.14 no.3
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    • pp.279-287
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    • 2020
  • Recently, interest in radiation protection is increasing because of the occurrence of accidents related to exposure dose. So, the nuclear safety act provides to install the shields to avoid exceeding the dose limit. In particular, when the worker conducts the non-destructive testing (NDT) without the fixed shielding structure, we should monitor the access to the workplace based on a constant dose rate. However, when we apply for permits for NDT work in these work environments, the consideration factors to the estimation of the distance and exposure dose are not legally specified. Therefore, we developed the excel model that automatically calculates the distance, exposure dose, and cost if we input the factors. We applied the assumption data to this model. As a result of the application, the distance change rate was low when the thickness of the lead blanket and collimator is above 25 mm, 21.5 mm, respectively. However, we didn't consider the scattering and build-up factor. And, we assumed the shape of the lead blanket and collimator. Therefore, if we make up for these limitations and use the actual data, we expect that we can build a database on the distance and exposure dose.

The Usefulness of Visceral Fat Thickness Measured by Ultrasonography as an Abdominal Obesity Index (초음파로 측정된 내장지방두께의 복부 비만지표로서의 유용성)

  • Kim, Yong-Kyun;Han, Man-Seok
    • Journal of radiological science and technology
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    • v.31 no.3
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    • pp.249-258
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    • 2008
  • Purpose : Abdominal obesity with visceral fat accumulation have been known to be intimately associated with the development of metabolic syndrome. Therefore, it is important to estimate the precise amount of visceral fat. Ultrasonography has been reported that it is a simple and noninvasive method for visceral fat evaluation. Purpose of this study is to evaluate the association of ultrasonographic visceral fat thickness, anthropometric indexes, and risk factor of metabolic syndrome, and to investigate the cut-off value of abdominal visceral fat thickness leading to increased risk of metabolic syndrome. Materials and methods : The subject included 200 men and 200 women who visited D healthcare center in Daejeon from January to April 2008. The subcutaneous fat thickness and visceral fat thickness were measured by ultrasonograph. As anthropometric index, we measured body mass index, waist circumference and waist/height ratio. As for the risk factor of metabolic syndrome, we measured blood pressure, high density lipoprotein cholesterol, triglyceride and fasting serum glucose. Results : VFT was significantly correlated with waist circumference, (r=0.683/M, r=0.604/F), waist to height ratio (r=0.633/M, r=0.593/F) and BMI (r=0.621/M, r=0.534/F) in both men and women. In addition it was significantly correlated with Systolic blood pressure (r=0.229/M, r=0.232/F), Diastolic blood pressure ((r=0.285/M, r=0.254/F), high density cholesterol (r=-0.254/M, r=-0.254/F), Triglyceride (r=0.475/M, r=0.411/F), and Fasting blood sugar (r=0.158/M, r=0.234/F) in both men and women. The cut-off value of visceral fat thickness leading to the increased risk of metabolic syndrome was 4.58cm (sensitivity89.2%, specificity 71.2%) in men and 3.50cm (sensitivity61.2% specificity 80.8%) in women respectively. The odds ratio of the risk of metabolic syndrome was dramatically increased with the abdominal visceral fat thickness level over 6cm in men and 5cm in women. Conclusion : The visceral fat thickness using ultrasonography was significantly correlated with anthropometric indexes and risk factors of metabolic syndrome in both men and women. The cut-off value of visceral fat thickness leading to the increased risk of metabolic syndrome was 4.58cm in men and 3.50cm in women.

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Radiation Exposure Dose Reduction on Upper Gastrointestinal Series (위장조영검사에서 피폭선량 저감)

  • Lim, Byung-Hak;Chon, Kwon Su
    • Journal of the Korean Society of Radiology
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    • v.11 no.2
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    • pp.109-116
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    • 2017
  • Upper gastrointestinal series is non-invasive examination, and it is useful for patients or elderly patients who have difficulty in endoscopic examination because of absence of any side effects other than temporary constipation or abdominal pain. The entire image of the gastrointestinal tract can be seen and have been widely used in the diagnosis of upper gastrointestinal diseases. However, there is a possibility that radiation dose increases due to improper movement and breath control, when examination is carried out by lack of understanding the overall inspection process for the upper gastrointestinal series. In upper gastrointestinal series to increase understanding of examination, to induce appropriate cooperation during examination, to reduce the number of retakes and shorten examination time, and to reduce dose of the subject, the procedure and precautions of the gastrointestinal test were made as a movie. We investigated the effectiveness of pre-education using the movie to reduce the inspection time, the number of re-shoots, and the reduction of exposure dose by watching the movie during the waiting time before examination. 120 patients that were selected each 20 patients aged from 30s to 80s were evaluated were evaluated for exposure dose, examination time, and the number of retakes before and after the movie training. The radiation dose, the examination time, and the number of retakes were respectively $3171.83{\mu}Gy{\cdot}m^2$ and $2931.73{\mu}Gy{\cdot}m^2$, 8.05 min, and 6.75 min, and 1.68 times and 1.22 times before and after movie training. It can be concluded that the movie training on the gastrointestinal examination influences the reduction of the examination time, the number of retakes and the reduction of the radiation dose.

The Acceptance Testing of 5 Mega Pixels Primary Electronic Display Devices and the Study of Quality Control Guideline Suitable for Domestic Circumstance (5 Mega 화소 진단용 전자표시장치 인수검사 및 국내 실정에 적합한 정도관리 가이드라인 연구)

  • Jung, Hai-Jo;Kim, Hee-Joung;Kim, Sung-Kyu
    • Progress in Medical Physics
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    • v.18 no.2
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    • pp.98-106
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    • 2007
  • In June 2005, Yonsei University Medical Center, Severance Hospital upgraded a full-PACS system by adding twenty (5 mega pixels) Totoku ME511L flat panel LCD display devices for diagnostic interpretation purposes. Here we report upon the quantitative (or visual) acceptance testing of the twenty Totoku ME511L display devices for reflection, luminance response, luminance spatial dependency, resolution, noise, veiling glare, and display chromaticity based on AAPM TG 18 report. The tools used in the tests included a telescopic photometer, which was used as a colorimeter, illuminance meter, light sources for reflection assessment, light-blocking devices, and digital TG18 test patterns. For selected 8 flat panel displays, mean diffuse reflection coefficient ($R_d$) was $0.019{\pm}0.02sr^{-1}$. In the luminance response test, luminance ratio (LR), maximum luminance difference ($L_{max}$), and deviation of contrast response were $550{\pm}100,\;2.0{\pm}1.9%\;and\;5.8{\pm}1.8%$, respectively. In the luminance uniformity test, maximum luminance deviation was $14.3{\pm}5.5%$ for the 10% luminance of the TG18-UNL10 test pattern. In the resolution test with luminance measurement method, percent luminance (${\Dalta}L$) at the center was $0.94{\pm}0.64%$. In all cases of noise testing, rectangular target In every square in the three quadrants was visible and all 15 targets except the smallest one in the every corner pattern and the center pattern. The glare ratio (GR) was $12,346{\pm}1,995$. The color uniformity, (u',v'), was $0.0025{\pm}0.0008$. Also, the research results of qualify control guideline of primary disply devices suitable for domestic circumstance are presented All test results are in-line with the criteria recommended by AAPM TG18 report and are thus fully acceptable for diagnostic image interpretation. As a result, the acceptance testing schedule described provides not only an acceptance standard but also guidelines for quality control, optimized viewing conditions, and a means for determining the upgrading time of LCD display devices for diagnostic interpretation.

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Radioprotective Effects of Aronia on Radiation Irradiated Rats (방사선에 조사된 쥐에서 아로니아의 방사선 방호효과)

  • Mun, Hwan-Sik;Lee, Jun-Haeng
    • Journal of radiological science and technology
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    • v.40 no.3
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    • pp.423-431
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    • 2017
  • The present study was intended to orally administer aronia to rats, irradiate radiation once to the whole bodies of the rats, and conduct blood tests to observe, compare, and analyze changes in blood cells, such as leukocytes, erythrocytes, and platelets, in order to examine the radioprotective effects of aronia. As experimental animals, 15 male Sprague-Dawley (SD) rats aged six weeks weighing 200~250 g were taken and divided into the normal group (A) of five rats, the 5 Gy control group (B) of five rats, and the 5 Gy experimental group (C) of five rats. The normal group (A) was not~irradiated at all, the control group (B) was administered with general diets and irradiated, and the experimental group(C) was orally administered with 50 mg/kg/day of aronia two times per day to achieve a distilled water oral dose of 100 mg/kg/day and irradiated thereafter (5 Gy at 500 cGy/min) for 14 days. After the experiment, differences in leukocytes, erythrocytes, and platelets among the normal group (A), the control group (B), and the experimental group (C) were examined by comparing the counts of the blood cells and the results showed no statistically significant differences. However, on a detailed review, the normal group (A) showed statistically higher mean values for all of lymphocytes, hemoglobin, and mean corpuscular hemoglobin as compared to the control group (B) and the experimental group (C). Statistically significant differences in the counts of lymphocytes were shown between the normal group (A) and the control group (B), and between the normal group (A) and the experimental group (C); furthermore, statistically significant differences in mean corpuscular hemoglobin were shown between the normal group (A) and the experimental group (C). Given the results of the present study, in irradiated rats, aronia was generally considered as having no radioprotective effect on leukocyte, erythrocyte, and platelet while having statistically significant radioprotective effects on lymphocytes, hemoglobin, and mean corpuscular hemoglobin. Based on the present experiment, diverse studies should be conducted hereafter.

Semi-automated Tractography Analysis using a Allen Mouse Brain Atlas : Comparing DTI Acquisition between NEX and SNR (알렌 마우스 브레인 아틀라스를 이용한 반자동 신경섬유지도 분석 : 여기수와 신호대잡음비간의 DTI 획득 비교)

  • Im, Sang-Jin;Baek, Hyeon-Man
    • Journal of the Korean Society of Radiology
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    • v.14 no.2
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    • pp.157-168
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    • 2020
  • Advancements in segmentation methodology has made automatic segmentation of brain structures using structural images accurate and consistent. One method of automatic segmentation, which involves registering atlas information from template space to subject space, requires a high quality atlas with accurate boundaries for consistent segmentation. The Allen Mouse Brain Atlas, which has been widely accepted as a high quality reference of the mouse brain, has been used in various segmentations and can provide accurate coordinates and boundaries of mouse brain structures for tractography. Through probabilistic tractography, diffusion tensor images can be used to map comprehensive neuronal network of white matter pathways of the brain. Comparisons between neural networks of mouse and human brains showed that various clinical tests on mouse models were able to simulate disease pathology of human brains, increasing the importance of clinical mouse brain studies. However, differences between brain size of human and mouse brain has made it difficult to achieve the necessary image quality for analysis and the conditions for sufficient image quality such as a long scan time makes using live samples unrealistic. In order to secure a mouse brain image with a sufficient scan time, an Ex-vivo experiment of a mouse brain was conducted for this study. Using FSL, a tool for analyzing tensor images, we proposed a semi-automated segmentation and tractography analysis pipeline of the mouse brain and applied it to various mouse models. Also, in order to determine the useful signal-to-noise ratio of the diffusion tensor image acquired for the tractography analysis, images with various excitation numbers were compared.

A Study on the General Characteristics, Correlation of COVID-19 and Prevention Behavior of Radiologists at K University Hospital (K 대학병원 방사선사의 COVID-19(코로나19)에 대한 일반적 특성, 지식 및 행위와 상관성, 감염 예방 행위에 관한 연구)

  • Choi, Hyeun-Woo;Park, Sung-Hwa;Cho, Eun-Kyung;Ryeom, Hunkyu;Lee, Jong-Min
    • Journal of the Korean Society of Radiology
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    • v.15 no.2
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    • pp.211-217
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    • 2021
  • The purpose of this study is based on the convergence establishment of a coronavirus infection management system that can occur during clinical trials by grasping the knowledge of corona, infection possibility, infection prevention possibility, and implementation level of infection prevention behavior of radiologists working at K University Hospital. It is in providing data. This study was a descriptive research study, and data were collected from 50 radiologists working at K University Hospital from March 25 to June 30, 2020. The characteristics of the subjects and their knowledge of the COVID-19, the possibility of infection, the possibility of infection prevention, and the level of implementation of infection prevention actions were surveyed, and the collected data were analyzed with SPSS 25.0. The frequency and percentage were calculated for the general characteristics and infection-related characteristics of the subjects. The correlation between variables was analyzed by Pearson's correlation coefficient, and the factors influencing the progression of infection prevention behavior were analyzed by multiple regression analysis. Factors influencing COVID-19 infection prevention behavior shown in this study were 1.7 points for infection prevention behavior when corona knowledge increased by 1 point, and infection prevention activity increased by 11.3 points when the level of transmission pathway recognition rose 1 point. When the figure rose by 1 point, the infection prevention behavior increased by 4.2 points. When looking at the standard regression coefficient, preventive behavior is performed. Among knowledge, transmission path perception, and anxiety, the factor that has the greatest influence was the perception of the transmission path of COVID-19. As factors influencing the implementation of infection prevention actions, knowledge of COVID-19, awareness of transmission paths, and anxiety appear to be the potential of infection prevention, so in the event of a corona outbreak, information on infectious diseases and education on the possibility of infection prevention should be provided to promote the implementation of preventive action.

Correlation Analysis of Diffusion Metrics (FA and ADC) Values Derived from Diffusion Tensor Magnetic Resonance Imaging in Breast Cancer (유방암의 확산텐서 자기공명 영상에서 유도된 확산 지표(FA, ADC) 값의 연관성 분석)

  • Lee, Jae-Heun;Lee, Hyo-Yeong
    • Journal of the Korean Society of Radiology
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    • v.12 no.6
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    • pp.755-762
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    • 2018
  • The purpose of this study was to compare the FA(faractional anisotropy) and ADC(apparent diffusion coefficient) values, which were derived from diffusion tensor imaging in breast cancer patients. The diffusion gradient used in this study was derived from quantitative diffusion indices using 20 directions(b-value, 0 and $1,000s/mm^2$). Quantitative analysis was analyzed using Pearson's correction and qualitative analysis using for correction coefficients. As a result, $FA_{min}$, $FA_{mean}$ and $FA_{max}$ were $0.098{\pm}0.065$, $0.302{\pm}0.142$ and $0.634{\pm}0.236$, respectively(p > 0.05). The $ADC_{min}$, $ADC_{mean}$ and $ADC_{max}$ were $0.741{\pm}0.403$, $1.095{\pm}0.394$ and $1.530{\pm}0.447$, respectively(p > 0.05). The $FA_{min}$, $FA_{mean}$, and $FA_{max}$ mean values were $0.132{\pm}0.050$, $0.418{\pm}0.094$, and $0.770{\pm}0.164$ for Category 6 and Kinetic Curve Pattern III, respectively. $ADC_{min}$, $ADC_{mean}$, and $ADC_{max}$ were $0.753{\pm}0.189$, $1.120{\pm}0.236$, and $1.615{\pm}0.372$, respectively. Quantitative analysis showed negative correlation between $ADC_{mean}-FA_{mean}$ and $ADC_{max}-FA_{max}$(p = 0.001, 0.003). The qalitative analysis showed ADC 0.628(p = 0.001), FA 0.620(p = 0.001) in the internal evaluations, ADC 0.677(p = 0.001), FA 0.695(p = 0.001) in external evaluations. In conclusion, based on the morphological examination, time to signal intensity graph is the form of wash-out(pattern III) in the dynamic contrast enhance examination, As a result, the $ADC_{mean}$ $1.120{\pm}0.236$ and $FA_{mean}$ values were $0.032{\pm}0.142$ with a negative correlation (Y=1.44-1.12X). Therefore, If we understand the shape of time to signal intensity graph and the relationship between ADC and FA, It will be a criterion for distinguishing malignant diseases in breast cancer.

Reduction of Artifacts in Magnetic Resonance Imaging with Diamagnetic Substance (반자성 물질을 이용한 자기공명영상검사에서의 인공물 감소)

  • Choi, Woo Jeon;Kim, Dong Hyun
    • Journal of the Korean Society of Radiology
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    • v.13 no.4
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    • pp.581-588
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    • 2019
  • MRI is superior when contrasted to help the organization generate artifacts resolution, but also affect the diagnosis and create a image that can not be read. Metal is inserted into the tooth, it is necessary to often be inhibited in imaging by causing the geometric distortion due to the majority and if the difference between the magnetic susceptibility of a ferromagnetic material or paramagnetic reducing them. The purpose of this study is to conduct a metal artefact in accordance with the analysis using a diamagnetic material. The magnetic material include a wire for the orthodontic bracket and a stainless steel was used as a diamagnetic material was used copper, zinc, bismuth. Testing equipment is sequenced using 1.5T, 3T was used was measured using a SE, TSE, GE, EPI. A self-produced phantom material was used for agarose gel (10%) to a uniform signal artifacts causing materials are stainless steel were tested by placing in the center of the phantom and cover inspection of the positive cube diamagnetic material of 10mm each length.After a measurement artefact artifact zone settings area was calculated using the Wand tool After setting the Low Threshold value of 10 in the image obtained by subtracting images, including magnetic material from a pure tool phantom images using Image J. Metal artifacts occur in stainless steel metal artifact reduction was greatest in the image with the bismuth diamagnetic materials of copper and zinc is slightly reduced, but the difference in degree will not greater. The reason for this is thought to be due to hayeotgi offset most of the susceptibility in bismuth diamagnetic susceptibility of most small ferromagnetic. Most came with less artifacts in image of bismuth in both 1.5T and 3T. Sequence-specific artifact reduction was most reduced artifacts from the TSE 1.5T 3T was reduced in the most artifacts from SE. Signal-to-noise ratio was the lowest SNR is low, appears in the implant, the 1.5T was the Implant + Bi Cu and Zn showed similar results to each other. Therefore, the results of artifacts variation of diamagnetic material, magnetic susceptibility (${\chi}$) is the most this shows the reduced aspect lower than the implant artificial metal artifacts criteria in the video using low bismuth susceptibility to low material the more metal artifacts It was found that the decrease. Therefore, based on the study on the increase, the metal artifacts reduction for the whole, as well as dental prosthesis future orthodontic materials in a way that can even reduce the artifact does not appear which has been pointed out as a disadvantage of the solutions of conventional metal artifact It is considered to be material.

The Study of Radiation Exposed dose According to 131I Radiation Isotope Therapy (131I 방사성 동위원소 치료에 따른 피폭 선량 연구)

  • Chang, Boseok;Yu, Seung-Man
    • Journal of the Korean Society of Radiology
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    • v.13 no.4
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    • pp.653-659
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    • 2019
  • The purpose of this study is to measure the (air dose rate of radiation dose) the discharged patient who was administrated high dose $^{131}I$ treatment, and to predict exposure radiation dose in public person. The dosimetric evaluation was performed according to the distance and angle using three copper rings in 30 patients who were treated with over 200mCi high dose Iodine therapy. The two observer were measured using a GM surverymeter with 8 point azimuth angle and three difference distance 50, 100, 150cm for precise radion dose measurement. We set up three predictive simulations to calculate the exposure dose based on this data. The most highest radiation dose rate was showed measuring angle $0^{\circ}$ at the height of 1m. The each distance average dose rate was used the azimuth angle average value of radiation dose rate. The maximum values of the external radiation dose rate depending on the distance were $214{\pm}16.5$, $59{\pm}9.1$ and $38{\pm}5.8{\mu}Sv/h$ at 50, 100, 150cm, respectively. If high dose Iodine treatment patient moves 5 hours using public transportation, an unspecified person in a side seat at 50cm is exposed 1.14 mSv radiation dose. A person who cares for 4days at a distance of 1 meter from a patient wearing a urine bag receives a maximum radiation dose of 6.5mSv. The maximum dose of radiation that a guardian can receive is 1.08mSv at a distance of 1.5m for 7days. The annual radiation dose limit is exceeded in a short time when applied the our developed radiation dose predictive modeling on the general public person who was around the patients with Iodine therapy. This study can be helpful in suggesting a reasonable guideline of the general public person protection system after discharge of high dose Iodine administered patients.