• Journal of radiological science and technology
• /
• v.35 no.2
• /
• pp.141-149
• /
• 2012

The aims of this study are to assess external radiation exposed doses of body and hands of nuclear medicine workers who handle radiation sources, and to measure radiation exposed doses of the hands induced by a whole body bone scan with high frequency and handling a radioactive sources like $^{99m}Tc$-HDP and $^{18}F$-FDG in the PET/CT examination. Skillful workers, who directly dispense and inject from radiation sources, were asked to wear a TLD on the chest and ring finger. Then, radiation exposed dose and duration exposed from daily radiation sources for each section were measured by using a pocket dosimeter for the accumulated external doses and the absorbed dose to the hands. In the survey of four medical institutions in Incheon Metropolitan City, only one of four institutions has a radiation dosimeter for local area like hands. Most of institutions uses radiation shielding devices for the purpose of protecting the body trunk, not local area. Even some institutions were revealed not to use such a shielding device. The exposed doses on the hands of nuclear medicine workers who directly handles radioactive sources were approximately twice as much as those on the body. The radiation exposure level for each section of the whole body bone scan with high frequency and that of the PET/CT examination showed that radiation doses were revealed in decreasing order of synthesis of radioactive medicine and installation to a dispensing container, dispensing, administering and transferring. Furthermore, there were statistically significant differences of radiation exposure doses of the hands before and after wearing a syringe shielder in administration of a radioactive sources. In this study, although it did not reach the permissible effective dose for nuclear medicine, the occupational workers were exposed by relatively higher dose level than the non-occupational workers. Therefore, the workers, who closely exposed to radioactive sources should be in compliance with safety management regulations, and take actions to maximally reduce locally exposed dose to hands monitoring with ring TLD.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.22 no.2
• /
• pp.84-87
• /
• 2018

Purpose The radiopharmaceutical used in the nuclear medicine department is used only for the specific patient according to the prescription or instruction of the doctor without selling, so it is dispensed and it is distributed and used for the examination. Radiopharmaceuticals administered to patients should be managed appropriately as well as radiation safety management during dispensation. The purpose of this study is to investigate microbial contamination during dispensation of radiopharmaceuticals Materials and Methods This study distinguished between general workbench and clean workbench and performed three tests. First, microbial cultivation test of radiopharmaceutical prepared and dispensed in general workbenches and sterile workbenches were carried out five times, respectively. The second test was performed settle plate method three times before and after the use of the exhaust filter. Finally, Adenosine Triphosphate (ATP) measurement was performed in each workbench to measure bacterial counts. In addition, ATP measurement were carried out by designating locations and items that may be contaminated during dispensation. Results In the microbial culture test, no microorganisms were detected in both samples. In the settle plate method, it was detected without using of the exhaust filter in a general workbench once. In the ATP measurement test, it was measured at the level of 400 RLU or less, which is the standard value of contamination, in both workbenches surface. In additional ATP measurement test, the refrigerator handle in the distribution room was measured above the reference value of 1217 RLU, the vacuum vial shield of the Tech Generator at 435 RLU, and the syringe holder at 1357 RLU. After environmental disinfection, the results were reduced to 311 RLU, 136 RLU, and 291 RLU. Conclusion No contamination by bacteria was found in both workbenches. However, microbial contamination may occur if the use of an exhaust filter or proper hand hygiene is not achieved. Regular inspections and management for aseptic processing themselves will be necessary.

• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.409-415
• /
• 2022

Plant growth and development are also affected by root-zone environment. Therefore, it is important to consider the variables of the root-zone environment when establishing an irrigation strategy. The purpose of this study is to analyze the relationship between the volumetric moisture content (VWC), Bulk EC (ECb), and Pore EC (ECp) used by plant roots using FDR sensors in two types of rockwool media with different water transmission characteristics, using the method above this was used to establish a method for collecting and correcting available root-zone environmental data. For the experiment, two types of rockwool medium (RW1, RW2) with different physical characteristics were used. The moisture content (MC) and ECb were measured using an FDR sensor, ECp was measured after extracting the residual nutrient solution from the medium using a disposable syringe in the center of the medium at a volumetric moisture content (VWC) of 10-100%. Then, ECb and ECp are measured by supplying nutrient solution having different concentration (distilled water, 0.5-5.0) to two types of media (RW1, RW2) in each volume water content range (0 to 100%). The relationship between ECb and ECp in RW1 and RW2 media is best suited for cubic polynomial. The relationship between ECb and ECp according to volume moisture content (VWC) range showed a large error rate in the low volume moisture content (VWC) range of 10-60%. The correlation between the sensor measured value (ECb) and the ECp used by plant roots according to the volumetric water content (VWC) range was the most suitable for the Paraboloid equation in both media (RW1, RW2). The coefficient of determination the calibration equation for RW1 and RW2 media were 0.936, 0.947, respectively.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.19 no.2
• /
• pp.74-80
• /
• 2015

Purpose Breast lymphoscintigraphy is an important technique to present for body surface precisely, which shows a lymph node metastasis of malignant tumors at an early stage and is performed before and after surgery in patients with breast cancer. In this study, we evaluated several methods of body outline imaging to present exact location of lesions, as well as compared respective exposure doses. Materials and Methods RANDO phantom and SYMBIA T-16 were used for obtaining imaging. A lesion and an injection site were created by inserting a point source of 0.11 MBq on the axillary sentinel lymph node and 37 MBq on the right breast, respectively. The first method for acquiring the image was used by drawing the body surface of phantom for 30 sec using $Na^{99m}TcO_4$ as a point source. The second, the image was acquired with $^{57}Co$ flood source for 30 seconds on the rear side and the left side of the phantom, the image as the third method was obtained using a syringe filled with 37 MBq of $Na^{99m}TcO_4$ in 10 ml of saline, and as the fourth, we used a photon energy and scatter energy of $^{99m}Tc$ emitting from phantom without any addition radiation exposure. Finally, the image was fused the scout image and the basal image of SPECT/CT using MATLAB$^{(R)}$ program. Anterior and lateral images were acquired for 3 min, and radiation exposure was measured by the personal exposure dosimeter. We conducted preference of 10 images from nuclear medicine doctors by the survey. Results TBR values of anterior and right image in the first to fifth method were 334.9 and 117.2 ($1^{st}$), 266.1 and 124.4 ($2^{nd}$), 117.4 and 99.6 ($3^{rd}$), 3.2 and 7.6 ($4^{th}$), and 565.6 and 141.8 ($5^{th}$). And also exposure doses of these method were 2, 2, 2, 0, and $30{\mu}Sv$, respectively. Among five methods, the fifth method showed the highest TBR value as well as exposure dose, where as the fourth method showed the lowest TBR value and exposure dose. As a result, the last method ($5^{th}$) is the best method and the fourth method is the worst method in this study. Conclusion Scout method of SPECT/CT can be useful that provides the best values of TBR and the best score of survey result. Even though personal exposure dose when patients take scout of SPECT/CT was higher than another scan, it was slight level comparison to 1 mSv as the dose limit to non-radiation workers. If the scout is possible to less than 80 kV, exposure dose can be reduced, and also useful lesion localization provided.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.16 no.1
• /
• pp.80-85
• /
• 2012

Purpose: The whole body bone scan is an examination that visualizing physiological change of bones and using bone-congenial radiopharmaceutical. The patients are intravenous injected radiopharmaceutical which labeled with radioactive isotope ($^{99m}Tc$) emitting 140 keV gammarays and scanned after injection. The 3 principles of radiation protection from external exposureare time, distance and shielding. On the 3 principles of radiation protection basis, radiopharmaceutical might just as well be injected rapidly for reducing radiation because it might be the unopened radiation source. However the radiopharmaceuticals are injected into patient directly and there is a limitation of distance control. This study confirmed the change of radiation exposure as change of distance from radiopharmaceutical and observed the change of radiation exposure afte rsetting a shelter for help to control radio-technician's exposure. Materials & methods: For calculate the average of injection time, the trained injector measured the injection time for 50 times and calculated the average (2 minutes). We made a source as filled the 99mTc-HDP 925 MBq 0.2 mL in a 1 mL syringe and measured the radiation exposure from 50 cm,100 cm,150 cm and 200 cm by using Geiger-Mueller counter (FH-40, Thermo Scientific, USA). Then we settled a lead shielding (lead equivalent 6 mm) from the source 25 cm distance and measured the radiation exposure from 50 cm distance. For verify the reproducibility, the measurement was done among 20 times. The correlation between before and after shielding was verified by using SPSS (ver. 18) as paired t-test. Results: The radiation doses according to distance during 2 minutes from the source without shielding were $1.986{\pm}0.052{\mu}$ Sv in 50 cm, $0.515{\pm}0.022{\mu}$ Sv in 100 cm, $0.251{\pm}0.012{\mu}$ Sv in 150 cm, $0.148{\pm}0.006{\mu}$ Sv in 200 cm. After setting the shielding, the radiation dose was $0.035{\pm}0.003{\mu}$ Sv. Therefore, there was a statistical significant difference between the radiation doses with shielding and without shielding ($p$<0.001). Conclusion: Because the great importance of whole body bone scan in the nuclear medicine, we should make an effort to reduce radiation exposure during radiopharmaceutical injections by referring the principles of radiation protection from external exposure. However there is a limitation of distance for direct injection and time for patients having attenuated tubules. We confirmed the reduction of radiation exposure by increasing distance. In case of setting shield from source 25 cm away, we confirmed reducing of radiation exposure. Therefore it would be better for reducing of radiation exposure to using shield during radiopharmaceutical injection.

• The Korean Journal of Nuclear Medicine
• /
• v.38 no.4
• /
• pp.300-305
• /
• 2004

Purpose: We underwent this study to evaluate the factors which influence labeling efficiency when modified in vivo erythrocyte labeling technique was used. Materials and methods: Thirty healthy volunteers (M:F=19:11, age:$25{\pm}2$ yrs) were enrolled in this study. Totally, two hundred ten samples were obtained from them. The 1 mg of stannous pyrophosphate was injected intravenously at the beginning of labeling. After suitable tinning time (5 min, 20 min, 35 min) passed by, blood (5 mL, 3 mL or 1 mL) was withdrawn into 10 mL syringe previously containing Tc-99m (740 MBq) and anticoagulant (heparin, ACD or CPDA) through 19-gauged scalp needle. The generator ingrowth time of Tc-99m was within 24 hrs in each case. The blood samples were placed on rotating invertor during incubation (10 min, 25 min, 40 min) but some of them were not. Immediately after the conclusion of incubation, the labeled blood specimens to analyze were centrifuged. and then %Unbound Tc-99m was calculated. Statical analysis was used paired T-test and one way ANOVA with SPSS 10.0. Results: The binding efficiency at 1 mL of blood volume was $73{\pm}32%,\;91{\pm}10%$ at 3 mL and $96{\pm}7%$ at 5 mL (p<0.01). The binding efficiency at 5 min of tinning time was $45{\pm}23%,\;98{\pm}6%$, at 20 min and $97{\pm}8%$ at 35 min (p<0.001). The binding efficiency at 10 min of incubation time was $96{\pm}7%,\;95{\pm}12%$ at 25 min and $98{\pm}3%$ at 40 min (p>0.05). The binding efficiency in case of using rotating invertor was $96{\pm}7%$ and the binding efficiency in case of not using it was $87{\pm}18%$ (p>0.05). There was no significant difference between them. In binding efficiency according to kinds of anticoagulants, ACD was $98{\pm}4%$, CPDA was $97{\pm}6%$ and heparin was $89{\pm}20%$ (p<0.001). Conclusion: When modified in vivo erythrocyte labeling technique is used with Tc-99m, the methods to obtain the highest labeling efficiency are as follow. The withdrawing blood volume should be over 3 mL, tinning time should be kept between 20 min and 35 min, and incubation time should be kept between 10 min and 40 min. ACD or CPDA have to be used as a anticoagulant except heparin and the blood samples should be placed on rotating invertor during incubation.

• Korean Journal of Veterinary Service
• /
• v.25 no.1
• /
• pp.53-73
• /
• 2002

It has been reported that degranulation of mast cells in rats, rabbits and dog was observed after dosing xylazine hydrochloride(Xh) which has been widely used as sedative, analgesic and muscular relaxant. Therefore, this experiment was conducted to examine the relations between Xh and histamine release and to identify the action of ${\alpha}$-adrenoceptors which exists on the suface of mast cells. 1. The content of histamine within serum was measured with HPLC by performing the O-phthalaldehyde(OPA) fluorescent derivation. The pretreatment method had a little modification from the conventional method. The pretreament was carried out in the following method. 0.2$m\ell$ of serum and 1$m\ell$ of butanol were added to mixed together and then the liquid was centrifugally separated at 4$^{\circ}C$ and 2,000 rpm for 3 minutes. 0.4$m\ell$ of 0.1N HCl and 1.6$m\ell$ of heptane were added to 0.8$m\ell$ of supernatant taken from the liquid, and they were mixed together. This mixture was also centrifugally separated at 4$^{\circ}C$ and 2,000 rpm for 5 minutes. The supernatant was thrown away and the OPA fluorescent derivation was carried out with 0.2$m\ell$ of the lower liquid then, 5 minutes after mixing 400${\mu}\ell$ of 0.1N HCl, 120${\mu}\ell$ of 1N NaOH and 40${\mu}\ell$ of 0.1% OPA in the 0.2$m\ell$ of the lower liquid,120${\mu}\ell$ of 3.57N H$_3$PO$_4$ was added to the mixed liquid, and the liquid, was mixed again and syringe-filtered. Then, the measurement was done with HPLC in the 30 : 70(ν/ν) ratio of 0.004M KH$_2$PO$_4$: CH$_3$CN, flow rate of 1.0$m\ell$/min., and a wavelength of λex= 350nm and λem=444nm at the column temperature of 27$^{\circ}C$, using the fluorescence detector. 2. The content of histamine in each laboratory animal appeared to be higher in such an order as rabbit, rat, guinea pig, dog, Korean indigenous goat, swine, Korean indigenous cattle, Holstein, and mouse, of which the individual mean values${\pm}$standard deviation were 2.0668 ${\pm}$ 0.6049. 0.4999 ${\pm}$ 0.2278, 0.4241 ${\pm}$ 0.1974, 0.1054 ${\pm}$ 0.0556, 0.1028 ${\pm}$ 0.0276, 0.0972 ${\pm}$ 0.0513, 0.0872 ${\pm}$ 0.0373, 0.0717 ${\pm}$ 0.0379, and 0.0706 ${\pm}$ 0.0366, respectively. 3. The content of histamine was measured at the moments of 15-, 30-, 60-, 120-minutes after inoamuscular injection of 20mg/100kg Xh into two to 4 years old Holstein weighing 600∼700kg. The result showed that there was a significant increase at the times of 30- and 90-minutes after injection(p<0.05). 4. Intramuscular injection of 3mg/10kg Xh was given to crossbred pug dogs weighing 2.5∼4.3kg. The content of histamine was measured at the times of 30-, 60-, 90- and 120-minutes after injection. The result revealed that there was a significant increase at the times of 60-and 90-minutes after injection(p<0.05). 5. Intramuscular injection of 10mg/$m\ell$∼25mg/$m\ell$ Xh in concentration of 0.1$m\ell$ was applied to Korean indigenous goat over 5 months old. Then, the content of histamine was measured at the times of 15-, 30-, 60- and 90-minutes after injection. A significant increase was shown at the times of 30- and 60-minutes after injection(p<0.05). 6. The content of histamine was measured at the moments of 30- and 60-minutes after intramuscular injection of 0.1-0.2$m\ell$ Xh (20mg/$m\ell$) into male rabbits weighting 2.5-4kg. A significant increase was found at the moment of 60 minutes after injection(p<0.001). 7. After administering Xh to the mast cell taken from the abdominal cavity of mouse, the content of histamine was measured. The result showed that the higher the concentration, the more significantly the content of histamine was increased(p<0.05). 8. Compound 48/80 was administered in concentration of 5$\mu\textrm{g}$/$m\ell$ and 10$\mu\textrm{g}$/$m\ell$ to the mast cell picked from the abdominal cavity of mouse. The result showed that there was a significant increase in the content of histamine in case of the concentration of 10$\mu\textrm{g}$/$m\ell$(p<0.05). It was found to be about 10,000 to 500,000 times stronger than the Xh. 9. After premedication of 1mg/kg of yohimbine hydrochloride as ${\alpha}$$_2$-adrenergic antagonist to rabbits, the Xh was administered to them. The result was that the value of histamine within serum was decreased significantly(p<0.001). 10. After premeditation of 1mg/kg of prazosin hydrochloride as ${\alpha}$$_1$-adrenergic antagonist to rabbits, the Xh was administered to them. It was found that the value of histamine within serum was decreased significantly(p<0.005). 11, Prazosin hydrochloride and yohimbine hydrochloride as ${\alpha}$$_1$-adrenergic antagonist, respectively, and ${\alpha}$$_2$-adrenergic antagonist were administerd. In this case, the value of histamine within serum was decreased significantly(p<0.0001). As the results, when the Xh is administered to various kinds of animals, the amount of histamine release within serum is increased. In view of the results so far achieved, it is concluded that Xh acted on both a$_1$-adrenoreceptor and ${\alpha}$$_2$-adrenoreceptor induces the degranulation of mast cell.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.31 no.2
• /
• pp.142-152
• /
• 1995

The combined bottom trawl and hydroacoustic survey was conducted by using the training ship Oshoro Maru belong to Hokkaido University in November 1989-1992 and the training ship Nagasaki Maru belong to Nagasaki University in April 1994 in the East China Sea, respectively. The aim of the investigations was to collect the target strength data of fish school in relation to the biomass estimation of fish in the survey area. The hydroacoustic survey was performed by using the scientific echo sounder system operating at three frequencies of 25, 50 and 100kHz with a microcomputer-based echo integrator. Fish samples were collected by bottom trawling and during the trawl surveys, the openings of otter board and net mouth were measured. The target strength of fish school was estimated from the relationship between the volume back scattering strength for the depth strata of bottom trawling and the weight per unit volume of trawl catches. A portion of the trawl catches preserved in frozon condition on board, the target strength measurements for the defrosted samples of ten species were conducted in the laboratory tank, and the relationship between target strength and fish weight was examined. In order to investigate the effect of swimbladder on target strength, the volume of the swimbladder of white croaker, Argyrosomus argentatus, sampled by bottom trawling was measured by directly removing the gas in the swimbladder with a syringe on board. The results obtained can be summarized as follows: 1.The relationship between the mean volume back scattering strength (, dB) for the depth strata of trawl hauls and the weight(C, $kg/\textrm{m}^3$) per unit volume of trawl catches were expressed by the following equations : 25kHz : = - 29.8+10Log(C) 50kHz : = - 32.4+10Log(C) 100kHz : = - 31.7+10Log(C) The mean target strength estimates for three frequencies of 25, 50 and 100 kHz derived from these equations were -29.8dB/kg, -32.4dB/kg and -31.7dB/kg, respectively. 2. The relationship between target strength and body weight for the fish samples of ten species collected by trawl surveys were expressed by the following equations : 25kHz : TS = - 34.0+10Log($W^{\frac{2}{3}}$) 100kHz : TS = - 37.8+10Log($W^{\frac{2}{3}}$) The mean target strength estimates for two frequencies of 25 and 100 kHz derived from these equations were -34.0dB/kg, -37.8dB/kg, respectively. 3. The representative target strength values for demersal fish populations of the East China Sea at two frequencies of 25 and 100 kHz were estimated to be -31.4dB/kg, -33.8dB/kg, respectively. 4. The ratio of the equivalent radius of swimbladder to body length of white croaker was 0.089 and the volume of swimbladder was estimated to be approximately 10% of total body volume.

• The Korean Journal of Physiology
• /
• v.15 no.1
• /
• pp.27-36
• /
• 1981

Relatively little has been done on the metabolic changes of the lung produced by the excessive alcohol ingestion to the point of the acute alcohol intoxication. In the present study, an effort was made to clarify the possible changes of the pulmonary surfactant system by the acute alcohol ingestion. The dynamic pulmonary compliance and the levels of protein and inorganic phosphorus (Pi) of both lung lavage and extract were chosen as the parameters of the pulmonary surfactant activities. The albino rats of both sexes were used, and 1.5 ml of 50% ethanol per 100 g body weight was given by oral intubation, and the experiment was performed at 1, 3, 6, 12, and 24 hours after the alcohol ingestion. The rat was sacrificed by cutting the carotid arteries, and blood sample for the determination of hematocrit(Hct) and the blood alcohol concentration was obtained. Both lungs were completely removed without dammage to the lung tissue, and the pulmonary compliance was measured by the changes of pressure-volume(P-V) curves by inflating or deflating the lung with air. Immediately after the P-V curves were recorded, the lung lavage was obtained by washing the lobes with 15ml of isotonic saline 3 times with a syringe. Next, total lungs were homogenized and filtered to obtain the lung extract. The protein and Pi levels were measured using the lung lavage and extract as the samples, and the lung/body weight ratio(L/B ratio) was also calculated. The results thus obtained were compared with the normal values and summarized as follows. The blood alcohol concentration reached the highest level of $0.71{\pm}0.02\;g\;%$ at 1 hr and gradually decreased until 24 hrs$(0.36{\pm}0.02\;g%)$ after the alcohol ingestion, but all the experimental groups showed significant increase comparing with the normal. The highest Hct value was obtained at 1hr$(64.86{\pm}2.45%)$ and significantly elevated value was continued throughout the experiment. The L/B ratio was significantly lowered from 3hrs until 24hrs after the alcohol ingestion but from 6 th hr on, a generally elevated value was observed with a significant value at 12 hrs and gradual recovery to the normal value at 24 hrs after the alcohol ingestion. The pulmonary compliance at inflation and deflation did not change appreciablly from the normal until 3 hrs after the alcohol ingestion but from 6 th hr on, a generally elevated value was observed with a significant value at 12 hrs and gradual recovery to the normal value at 24 hrs after the alcohol ingestion. The protein level of the lung lavage stowed a significantly increased value of $12.36{\pm}0.35\;mg/gm(3rd hr)$, $12.70{\pm}0.74\;mg/gm(12 th hr)$, and $12.65{\pm}0.88\;mg/gm(24 th hr)$, respectively, comparing with the normal value of $10.65{\pm}0.62\;mg/gm$, and the Pi level also showed a similar tendency of significant increase at 12th hr $(7.65{\pm}0.63\;{\mu}mol/gm)$ and 24 th hr$(6.70{\pm}0.36\;{\mu}mol/gm)$ comparing with the normal value of $5.32{\pm}0.20\;{\mu}mol/gm$. The protein level of the lung extract in the alcohol group was generally similar to the normal value with a slight decrease at 1st and 3 rd hr, tut the Pi level of the lung extract was generally increased in the alcohol group, and a significant increase was observed at 6 th hr$(17.77{\pm}1.54\;{\mu}mol/gm)$, 12 th hr$(13.92{\pm}0.78\;{\mu}mol/gm)$ and 24 th hr$(14.57{\pm}0.53\;{\mu}mol/gm)$ of the alcohol ingestion comparing with the normal value of $10.34{\pm}0.37\;{\mu}mol/gm$. From the above, it may be concluded that the acute alcohol intoxication produces the metabolic changes of the lungs by the increased surfactant activities and elevated pulmonary compliance.