• Journal of the Korean Society of Radiology
• /
• v.12 no.2
• /
• pp.185-191
• /
• 2018

The purpose of this study was to evaluate the usefulness of BMI application to Urography CT by applying different tube voltages in accordance with body mass index. Group A (n = 38) with body mass index of lower than 25 was examined with tube voltage of 100 kVp while Group B (n = 45) with a BMI of 25 and higher was examined with tube voltage of 120 kVp. C group (n = 37) with body mass index (BMI) of lower than 25 was examined with tube voltage of 120kVp. Although the difference in average dose between group A (100 kVp) and group C (120 kVp) with low body mass index (BMI) of lower than 25 was $214.8mGy{\cdot}cm$, there was no significant difference in qualitative evaluation and, compared with patient group with body mass index of 25 and higher, results obtained were rather good. Therefore, this study verified that the tube voltage of lower than 100 kVp does not have adverse effect on the quality of image for patients with body mass index (BMI) of lower than 25.

• Journal of radiological science and technology
• /
• v.28 no.2
• /
• pp.137-144
• /
• 2005

To find the personal radiation dose of radiological technologists, a survey was conducted to 623 radiological technologists who had been working at 44 general hospitals in Korea's 16 cities and provinces from 1998 to 2002. A total of 2,624 cases about personal radiological dose that were collected were analyzed by region, year and hospital, the results of which look as follows : 1. The average radiation dose per capita by region and year for the 5 years was 1.61 mSv. By region, Daegu showed the highest amount 4.74 mSv, followed by Gangwon 4.65 mSv and Gyeonggi 2.15 mSv. The lowest amount was recorded in Chungbuk 0.91 mSv, Jeju 0.94 mSv and Busan 0.97 mSv in order. By year, 2000 appeared to be the year showing the highest amount of radiation dose 1.80 mSv, followed by 2002 1.77 mSv, 1999 1.55 mSv, 2001 1.50 mSv and 1998 1.36 mSv. 2. In 1998, Gangwon featured the highest amount of radiological dose per capita 3.28 mSv, followed by Gwangju 2.51 mSv and Daejeon 2.25 mSv, while Jeju 0.86mSv and Chungbuk 0.85 mSv belonged to the area where the radiation dose remained less than 1.0 mSv In 1999, Gangwon also topped the list with 5.67 mSv, followed by Daegu with 4.35 mSv and Gyeonggi with 2.48 mSv. In the same year, the radiation dose was kept below 1.0 mSv. in Ulsan 0.98 mSv, Gyeongbuk 0.95 mSv and Jeju 0.91 mSv. 3. In 2000, Gangwon was again at the top of the list with 5.73 mSv. Ulsan turned out to have less than 1.0 mSv of radiation dose in the years 1998 and 1999 consecutively, whereas the amount increased relatively high to 5.20 mSv. Chungbuk remained below the level of 1.0 mSv with 0.79 mSv. 4. In 2001, Daegu recorded the highest amount of radiation dose among those ever analyzed for 5 years with 9.05 mSv, followed by Gangwon with 4.01 mSv. The area with less than 1.0 mSv included Gyeongbuk 0.99 mSv and Jeonbuk 0.92 mSv. In 2002, Gangwon also led the list with 4.65 mSv while Incheon 0.88 mSv, Jeonbuk 0.96 mSv and Jeju 0.68 mSv belonged to the regions with less than 1.0 mSv of radiation dose. 5. By hospital, KMH in Daegu showed the record high amount of average radiation dose during the period of 5 years 6.82 mSv, followed by GAH 5.88 mSv in Gangwon and CAH 3.66 mSv in Seoul. YSH in Jeonnam 0.36 mSv comes first in the order of the hospitals with least amount of radiation dose, followed by GNH in Gyeongnam 0.39 mSv and DKH in Chungnam 0.51 mSv. There is a limit to the present study in that a focus is laid on the radiological technologists who are working at the 3rd referral hospitals which are regarded to be stable in terms of working conditions while radiological technologists who are working at small-sized hospitals are excluded from the survey. Besides, there are also cases in which hospitals with less than 5 years since establishment are included in the survey and the radiological technologists who have worked for less than 5 years at a hospital are also put to survey. We can't exclude the possibility, either, of assumption that the difference of personal average radiological dose by region, hospital and year might be ascribed to the different working conditions and facilities by medical institutions. It seems therefore desirable to develop standardized instruments to measure working environment objectively and to invent device to compare and analyze them by region and hospital more accurately in the future.

• Journal of Food Hygiene and Safety
• /
• v.25 no.1
• /
• pp.43-48
• /
• 2010

This research was conducted to know application of Photostimulated luminescence (PSL) and Thermoluminesce(TL) methods by irradiation dose for leaching tea, sauces and starch approved in Korea. Leaching tea, sauces and starch powder were treated with $^{60}Co$ gamma ray at dose 0~10 kGy for detection trial whether they are irradiated or not by measuring PSL and TL for whole samples. PSL values were less than threshold value 700 and were, negative for non-irradiated samples but more than 5,000 and were positive for irradiated ones. PSL results of leaching tea and sauces showed the correct identification for non-irradiated and irradiated samples, respectively except starch samples. To enhance the reliability of the TL result, the first glow curve (TL1) was compared with the second glove curve (TL2) obtained after a re-irradiation step at 1 kGy. The TL ratio ($TL_1/TL_2$) was in good agreement with the reported TL threshold for both the non-irradiated (< 0.1) and irradiated (> 0.1) samples. TL results of leaching tea, sauces, starch showed the correct identification for non-irradiated and irradiated samples, respectively. This study was performed to know application of PSL and TL methods for leaching tea, sauces and starch, and the methods were able to detect the irradiation products.

• Journal of radiological science and technology
• /
• v.21 no.1
• /
• pp.79-87
• /
• 1998

The total-bodies of 10 week-old Sprague-Dawley rats were irradiated with single doses 4.5 and 7.5 Gy, respectively. The effects on plasma and sciatic nerve platelet-derived growth factor(PDGF) concentrations and sciatic nerve PDGF ${\alpha}$ -and ${\beta}$ -receptors densities were examined up to 10 days post-treatment. There was no consistent significant variation in the plasma and sciatic nerve PDGF concentrations in time over the period of study between 4.5 and 7.5 Gy groups. Plasma PDGF concentrations were significantly reduced to 58% of control values between 5 and 10 days with 4.5 Gy and to 51% of control values as percentage of control values between 5 and 10 days with 7.5 Gy after irradiation, respectively(p<0.05). Sciatic nerve PDGF concentrations were increased to 118% of control values at 1 day with 4.5 Gy and to 130% of control values at 1 day with 7.5 Gy after irradiation, respectively(p>0.05). After irradiation, the levels of PDGF ${\alpha}$ -receptor protein density were reduced to 33% of control values at 2 days with 4.5 Gy and to 50% at 2 days with 7.5 Gy, while the levels of PDGF ${\beta}$-receptor protein density were reduced to maximally 26% of control values at 2 days with 4.5 Gy and to 27% at 2 days with 7.5 Gy, respectively, but both initial decreased levels of those were increased subsequently after 2 days following irradiation. These results suggest that the radiation-induced alteration of plasma and sciatic nerve PDGF concentrations, and sciatic nerve PDGF ${\alpha}$ -and ${\beta}$ -receptors densities may be involved in the pathogenesis of bone marrow stem cell and peripheral neuron damages.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.20 no.1
• /
• pp.28-31
• /
• 2016

Purpose $^{223}Ra-Dichloride$ is used for the medicine of castration-resistant prostate cancer (CRPC) and which emits ${\alpha}-ray$ of 28 Mev that is used for therapy. However $^{223}Ra-Dichloride$ emits ${\beta}-ray$ of 3.6% and ${\gamma}-ray$ of 1.1%(80,156,270 keV) aside from ${\alpha}-ray$ in decay. Therefore we would like to evaluate external radiation expose dose rate of ${\gamma}-ray$ of $^{223}Ra-Dichloride$. Materials and Methods We calculated external radiation expose dose rate using ${\gamma}-constant$ of $^{223}Ra-Dichloride$, $^{99m}Tc$ based on Health physics(2012). $^{223}Ra-Dichloride$ of 3.5 MBq and $^{99m}Tc-MDP$ of 740 MBq were applied. external radiation expose dose rate 15 times from 1m by survey meter. Results ${\gamma}-contant$ of $^{223}Ra$, $^{99m}Tc-MDP$ from 1m distance based on Health physics(2012) is 0.0469, 0.0215. calculated value of external radiation expose dose rate was $16{\mu}Sy$, $34{\mu}Sy$ which activity is $^{223}Ra-Dichloride$ of 3.5 MBq and $^{99m}Tc-MDP$ of 740 MBq from 1 m and measured mean value of 1 m was $0.7{\mu}Sy/h$, $18{\mu}Sy/h$. Conclusion ${\gamma}-constant$ of $^{223}Ra$ is higher than $^{99m}Tc$ based on Health physics(2012). however calculated maximum external radiation expose dose rate of $^{223}Ra-Dichloride$ is lower than $^{99m}Tc$ due to actually used quantity of activity of $^{223}Ra-Dichloride$ is small. measured value of $^{223}Ra-Dichloride$ is also lower than $^{99m}Tc-MDP$. Therefore external radiation expose dose rate of ${\gamma}-ray$ of $^{223}Ra-Dichloride$ is very low.

• Food Science and Preservation
• /
• v.10 no.2
• /
• pp.206-212
• /
• 2003

Comparative effects of electron beam and gamma-ray irradiation (25 ∼15 kGy) were investigated on saponin stability and some physiological and chemical properties of white and red ginseng powders. Saponin components were found stable upon irradiation of both energies when determined by TLC and HPLC, after 4 months of storage at room temperature as well as immediately after treatment The contents of total phenolics and acidic polysaccharides of the samples were higher in red ginseng than in white. Polysaccharide contents increased with irradiation doses. Amylase activity of white ginseng was stimulated by irradiation but decreased with the lapse of storage time. There were no apparent differences in electrophoresis patterns of extracted proteins depending on irradiation doses and energy sources.

• Journal of Radiation Protection and Research
• /
• v.1 no.1
• /
• pp.1-9
• /
• 1976

A suggestion has been made for neutron dosimetric techniques using activation and threshold detectors in criticality accidents. Neutron dosimetrical parameters, namely, the fission spectrum-averaged cross-sections of some threshold reactions and fluence-to-dose conversion factors have been calculated by the use of an electronic computer. It appears that detectors having comparatively high threshold energy give more fine information on spectral deformation in criticality accidents, while detectors with low threshold energy are of usefulness for measuring fast neutron fluence regardless of fissioning types. Unexpectedly it is found that the fission spectrum-averaged cross sections of the $^{32}S(n,\;p)^{32}P$ reaction is not sensitive to analytical forms of fission neutron spectrum: the modified Cran-berg and Maxwellian forms. In addition, the fluence-to-dose conversion factors seem to be insensitive to both spectral functions and fissioning types.

• Korean Journal of Human Ecology
• /
• v.4 no.1
• /
• pp.62-67
• /
• 2001

Effects of irradiation on the physical and functional characteristics of egg whites were investigated. Fresh shell eggs were irradiated at 0, 0.5, 1.0, 2.0 and 3.0kGy. Egg whites were separated from eggs kept at 3$0^{\circ}C$ for 2hr. There was a considerable decrease in viscosity of egg whites with irradiation. Irradiation made egg whites darker and less greenish. The foaming properties including foaming ability and stability were examined. Irradiation led to increase in whipping power and decrease in drainage in an irradiation dose-dependent manner. These results showed that irradiated egg whites had good foaming ability and stability.

• Journal of the Korean Society of Radiology
• /
• v.14 no.5
• /
• pp.537-543
• /
• 2020

The elderly population in the modern society is growing rapidly due to advance medical technology and minimally invasive surgery. Therefore, as the tendency to use medical device is increasing, pathogenic infection is a concern. Therefore, the first aim of modern medicine is infection prevention in medical place. Recently, patient implants are increasing using 3D printing. Hydroxyapatite is used as a representative material. And, there haven't had currently absorbed dose standard for sterilization of hydroxyapatite discs. Escherichia coli and Streptococcus mutans contaminated on the surface of hydroxyapatite discs were irradiated at each absorbed dose of 0, 0.5, 1.0, 3.0, 5.0 kGy using Gamma-ray of cobalt and Electron-beam of linear accelerator. Then, the number of bacteria was measured in the sample by the decimal dilution method. After sterilization, a non-parametric testing method was performed to compare the survival of Escherichia coli and Streptococcus mutans. As a result, Escherichia coli was sterilized at 1 kGy or more and Streptococcus mutans at 3 kGy or more on absorbed dose. It is considered possible to perform sterilization at a lower value than the recommended absorbed dose of radiation sterilization.

• Progress in Medical Physics
• /
• v.16 no.4
• /
• pp.202-206
• /
• 2005

Three-dimensional thermoluminescence (TL) spectra from $MgAl_2O_4$ irradiated with UV light were measured over 300${\~}$600 K and 300${\~}$800 nm. The peak positions of TL glow curves were shifted to lower temperature with increasing the exposure time of UV light. The 476 K TL glow curve is due to the second kinetics and its activation energy and escape frequency factor are calculated to be 0.85 eV and $1.92{\times}10^6 sec^{-1}$, respectively The TL spectra were split into 530 nm and 700 nm emission bands which were associated with $V^{2+}$ and $Cr^{2+}$, respectively. The linearity range of 700 nm omission band is smaller than that of 530 nm emission band, but the saturation time of 700 nm emission band is longer than that of 530 nm omission band.