• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.53-58
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• 2013

Purpose: To optimize correction method for SPECT/CT, image quality consisting of resolution and contrast was evaluated using three radioisotopes ($^{99m}Tc$, $^{201}Tl$ and $^{131}I$) and three different correction methods; attenuation correction (AC), scatter correction (SC) and both attenuation and scatter correction (ACSC). Materials and Methods: Images were acquired with a SPECT/CT scanner and a conventional CT protocol with an OESM reconstruction algorithm (2 iterations and 10 subsets). For resolution measurement, fixed radioactivity (2.22 kBq) was infused into a spatial resolution phantom and full width at half maximum (FWHM) was measured using a vendor-provided software. For contrast evaluation, radioactive source with a ratio of 1:8 to background was filled in a Flanged Jaszczak phantom and percent contrast (%) were calculated. All the parameters for image quality were compared with non-correction (NC) method. Results: As compared with NC, image resolution of all three isotopes were significantly improved by AC and ACSC, not by SC. In particular, ACSC showed better resolution than AC alone for $^{99m}Tc$ and $^{201}Tl$. Image contrast of all three radioisotopes in a sphere with the largest diameter were enhanced by all correction methods. ACSC showed the highest contrast in all three radioisotopes, which was the most accurate in $^{99m}Tc$ (85.9%). Conclusion: Image quality of SPECT/CT was improved in all the radioisotopes by CT-based attenuation correction methods, except SC alone. SC failed to improve resolution in any radioisotopes, but it was effective in contrast enhancement. ACSC would be the best correction method as it improved resolution in radioisotopes with low energy levels and contrast in radioisotope with low energy levels. However, in radioisotope with high energy level, AC would be better than ACSC for resolution improvement.

• Journal of Radiation Industry
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• v.17 no.2
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• pp.127-134
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• 2023

Pharmacokinetic (PK) data provide pivotal information in drug development, and they are usually first studied in the preclinical stage using various animals. However, quite often, animal PK data may not match with human PK, especially in metabolites. Thus, most regulatory agencies in the world make it mandatory to obtain metabolite information using ¹⁴C radiolabeled drug in human for small molecule drug candidates. However, such studies are expensive and time consuming and they are usually done at the end of Phase II trials using ~3.7 MBq of ¹⁴C labeled drug in a limited number of human subjects. Introduction of accelerator mass spectrometry (AMS) in this kind of study has revolutionized it. Since AMS can measure ¹⁴C level as close as natural abundance, it can quantify the amounts of ¹⁴C labeled drugs and their metabolites produced in human body that consumes less than the amount of 0.0037 MBq of ¹⁴C labeled drug, a very safe level of radioactive dose in human. Therefore, it is now possible to conduct human ¹⁴C studies safely in early clinical trials without spending hefty amount of money and time. Korea Radioisotope Center for Pharmaceuticals(KRICP) at Korea Institute of Biological and Medical Sciences(KIRAMS) has established an AMS facility in 2018, housing a 0.5MV AMS manufactured at the US National Electrostatics Corps (NEC). The AMS instrument has been validated using various standard samples that have been prepared at Lawrence Livermore National Laboratory in the US, a worldly reputable provider of AMS standards. In this paper, we present a mass balance study for acetaminophen in rats using AMS and prove that the study results are equivalent with those of literature, which shows the AMS facilities at KRICP has successfully installed and be ready to be used in the various PK studies using ¹⁴C labelled compounds for new drug development.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.242-242
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• 1994

Cortex mori (Morus alba L.), the root bark of mulberry tree, has been used as an antiphlogistic, diuretic, and expectorant in herbal medicine. The purpose of this study was to determine whether Cortex mori could inhibit the ovalbumin (OA) -induced late asthmatic reaction in guinea pigs. Guinea pigs were sensitized by two exposures to an aerosol of OA(1.0%) and then challenged with aerosolized antigen(2.0%), The animals were pretreated by three inhalations of the aerosoled Cortex mori either before antigen sensitization or cahllenge. Bronchoalveolar lavage fluid(BALF) and peripheral blood were collected at 17 hours after OA challenge. The cell populations in BALF and peripheral blood were examined to determine the changes of the relative proportions of eosinophils,neutrophils and mononuclear cells etc. Beta-glucuronidase activity in BALF was measured to evaluate the alveolar macrophage activation. OA-induced histamine release from guinea pig peritoneal fluid cells was measured by radioisotope enzymatic asssay. Results were as follows. The number of eosinophils, neutriphils and lymphocytes recovered in BALF were significantly increased in the 17h following aerosol challenge with OA. Among them, eosinophil and neutriphils were decreased remarkably in group that had been preinhalated with Cortex mori. The number of lymphocytes in BALF were not decreased in group pretreated with CM before sensitization but decreased in Group pretreated with CM before challenge. After OA challenge, the number of eosinophils in peripheral blood were markedly increased, but Cortex mori inhibited significantly the OA-induced eosinophilia. Beta-glucuronidase activity in the supernatants of BALF were significantly increased in the 17h following aerosol challenge with OA, however, pretreatment of Cortex mori had no influence on Beta-glucuronidase activity, suggesting that Cortex mori had no inhibitory effect on OA-induced alveolar macrophage activation. Cortex mori inhibited the OA-induced histamine release from guinea pig peritoneal fluid cells. From the above results, it is suggested that Cortex mori contains some substances with an activity to inhibit the the OA-induced late phase reaction of the bronchial asthma in guinea pigs.

• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.1-8
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• 2017

Background: The use of radiation and radioisotopes in Korea has been increasing each year, and its impact on economy and industry is expected to be increasing progressively following the development of industrial technology and the expansion of their usage. To establish and supporting policies for industries using radiation and radioisotopes, it is necessary to check the status of related industries accurately, as well as to gather data required to establish plans for industrial development by studying both revenues and economic scale (contributing to revenue). Materials and Methods: To analyze the status of utilization, surveys were carried out on 6,621 organizations engaged in nuclear operations handling radiation and radioisotopes pursuant to the Nuclear Safety Act as of end 2014, on 33,471 medical institutions using radiation generators for medical and diagnostic purposes pursuant to the Medical Service Act, and on 2,218 organizations using radiation generators for animal diagnostics pursuant to the Veterinary License Act. Results and discussion: The overall status of the domestic radiation market including the number of user organizations, that of employees, and the size of distributions (imports, productions, and exports) with which the scale of domestic radiation market can be judged showed a growth trend compared to the previous year, though the number of employees for radiation operation in industrial sector, research sector, education sector, military sector, and power plants (nuclear power plants) and the size of imports was reduced somewhat. Conclusion: It is expected that data acquired through periodic surveys on the status of utilization would be utilized practically in establishing governmental policies related to the promotion of usage of radiation and radioisotopes, and also be utilized widely in cultivating and developing the industry efficiently to invigorate the related industries.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.1-8
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• 2005

This paper is described on the development of KOTRON-13 and recent status of PET cyclotron by commercial cyclotron companies. KIRAMS has developed medical cyclotron which is KIRAMS-13. Samyoung Unitech produces KOTRON-13 with transfered technology by KIRAMS. As a part of Regional Cyclotron Installation Protect, KOTRON-13 cyclotrons and $[18F]FDG$ production modules are being installed at regional cyclotron centers in Korea. The medical concern with radiation technology has been growing for the last several years. Early cancer diagnosis through the cyclotron and PET-CT have been brought to public attention by commercial cyclotron models in the world. The new commercial cyclotron models are introduced compact low energy cyclotrons developed by CTI, GE, Sumitomo in recent. It produces different short-lived radioisotopes, such as $[^{18}F],\;[^{11}C],\;[^{13}N]\;and\;[^{15}O]$. For the better reliability acceleration particle is proton only. The characteristics of new model cyclotrons are changed to lower energy corresponding to less 13 MeV. New models have self-shielding and low power consumption. Design criteria for the different types of commercial cyclotrons are described with reference to hospital demands.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.4 no.2
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• pp.65-72
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• 2018

Prostate specific membrane antigen (PSMA) is a cell surface membrane protein, which is overexpressed in most prostate cancer. Recently, PET imaging with $[^{68}Ga]$PSMA-HBED-CC has been widely used for the diagnosis of recurrent prostate cancer and the studies on the diagnostic potential of $^{64}Cu$-labeled PSMA ligands reported actively. In this study, we monitored with biological evaluation in vivo and PET imaging of $^{64}Cu$-labeled PSMA ligand ($[^{64}Cu]$PSMA-617). The radiolabelling efficiency and stability of $[^{64}Cu]$PSMA-617 were confirmed by radio-thin layer chromatography. The radiolabeling efficiency of $[^{64}Cu]$PSMA-617 showed over 95%, and stabilities of intact remained over 98% in both human and mouse serum for 48 h. In normal male mice, in vivo uptake of $[^{64}Cu]$PSMA-617 in several organs was measured at 2, 4, 6, 24, 48 h after injection. Rapid blood clearance was observed for $[^{64}Cu]$PSMA-617. The high uptake was observed in the lung, liver, intestines and kidneys at 2 h postinjection, but was low in the other organs (1-2 %ID/g) at 4 h. The dynamic PET/CT images of 22RV1 tumor-bearing nude mice were acquired during 60 min and additionally acquired 24 h and 48 h after injection. In dynamic PET images, $[^{64}Cu]$PSMA-617 uptake ratio in tumors versus muscle was increased as time elaplsed until 60 minutes and remained in tumors at 48 h. In these results, the PET/CT imaging using $[^{64}Cu]$PSMA-617 in prostate cancer is expected to be useful for the diagnosis and treatment of prostate cancer patients.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.388-394
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• 1997

Temporomandibular (TM) joint Pain results from many etiologic factors. The aim of this study was to evaluate the utility of Bone SPECT in patients with TM joint pain. The subjects were 34 patients with TM joint pain. All patients underwent plain radiography, planar bone scan, and Bone SPECT The intensity of radioisotope uptake at TM joint was graded into three; no increased uptake above the background activity as grade 0, uptake similar to occipital bone as grade I, and uptake similar to maxillary sinus as grade II. Clinical findings and therapeutic methods were reviewed. Twenty-seven patients (80%) out of 34 patients with TM joint pain had increased uptake in bone SPECT. Twenty-one (78%) out of 27 patients had increased uptake in the mandibular condyle and remaining six patients (22%) had uptake in the mandibular and maxillary arch, which proved to be dental problem. Seven patients (21%) out of 34 were grade as 0, four (12%) were grade I, 23 (68%) were grade II. Four patients with grade I had clicking sound and symptoms which were subsided with medication in all cases. Among 23 patients with grade II, 7 patients had clicking sound and 14 patients underwent medication and decompression therapy. With Planar bone scan, 11 cases (32%) had increased uptake in TM joint area. Plain radiography revealed narrowing, distension, erosion and limitation of TM joint in 16 cases (47%). Bone SPECT can be valuable for screening and managing the patients with TM joint pain. Patients with grade II needed intensive treatment such as joint aspiration. However degree of the radioisotope uptake did not well correlated with clinical symptoms.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.210-217
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• 1997

Purpose: To prevent residual physical disability and chronic infection, prompt diagnosis and adequate treatment are important in the skeletal infections in children. Although radioisotope scanning is knwon as the method of choice for early diagnosis of bone infection, we conducted a study on twenty nine children who had skeletal infections to reevaluate the most appropriate way in diagnosis and management. Methods: A retrospective study was conducted on twenty nine children, who were admitted to the departments of Pediatrics and Orthopedic Surgery and who had acute osteomyelitis or septic arthritis, through review of medical records, radiologic & radioisotope study results. Their diagnoses were confirmed by bacteriologic cultures on the aspirated specimens from suspected bony lesions. Results: 1) Among twenty nine patients, there were 6 infants including 5 newborn infants, and 23 children were aged between 1 and 15 years. Male to female ratio was 1.4 to 1. 2) Point tenderness was noted in all cases, and the common physical signs were swelling, limitation of motion, fever and local heat in the order of frequency. 3) Fifty two percents of the patients were diagnosed within a week after onset of symptoms and all cases were within 15 days. 4) Leukocytosis was noted in only 58.6% of cases but erythrocyte sedimentation rate was increased in all cases except only one case. Staphylococcus aureus was revealed as the most common etiologic agent. 5) Radioisotope scans showed hot uptake in five of six cases(83.3%) who had no abnormal finding on plain skeletal radiolograms. Conclusions: Although radioisotope scan and MRI are helpful in early diagnosis before radiologic finding was detected on plain X-ray film, the antimicrobial therapy can be started after bacteriologic study of the aspirated specimens from the suspected skeletal lesions if skeletal infection is highly suspected clinically.

• The Korean Journal of Nuclear Medicine
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• v.14 no.2
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• pp.53-60
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• 1980

The radioimmunoassay of TSH (human thyrotropin) was performed by utilizing anti-h-TSH antibody and purified human thyrotropin supplied from Daiichi Radioisotope company in Japan. From Jan. 1978 through Aug. 1980 the serum concentration of TSH was measured on 41 cases with various thyroid diseases, and 22 normal persons. Among 41 cases, 9(22%) were primary hypothyroidism, 17(41%) Graves' disease, 8(20%), subacute or chronic lymphocytic thyroiditis, and 7(17%) nodular goiter. The results were as follows: 1) The normal values of serum TSH in 22 cases of control group were $4.2{\pm}1.7{\mu}U/ml(1.9-7.4{\mu}U/ml)$, which were within normal range in kit used in this study. 2) The serum TSH concentration in 9 cases with primary hypothroidism were $97.1{\pm}116.4{\mu}U/ml(14.0-300{\mu}U/ml)$, which were significantly elevated as compared with normal control values. 3) The serum TSH concentration in 17 cases with Graves' disease were $1.5{\pm}0.6{\mu}U/ml(1.0-2.5{\mu}U/ml)$, which were below than normal control. 4) The serum TSH concentration in 8 cases with subacute or chronic lymphocytic thyroiditis. revealed wide ranges ($1.6-220{\mu}U/ml$) according to the state of thyroid function. 5) The serum TSH values in 7 cases with nodular goiters were $2.3{\pm}2.0{\mu}U/ml$, which were strictly within normal levels. 6) The serum TSH levels were elevated during prolonged treatment with Tapazole (Methimazole) without serial check of the serum TSH concentration in Graves' disease, so the serial measurement of serum TSH concentration was considered of available index of thyroid states.

• The Korean Journal of Nuclear Medicine
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• v.14 no.2
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• pp.19-27
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• 1980

Although primary application of radioisotope scanning technics to the liver has been of use in the detection of the intra-hepatic space occupying lesion from the normal functioning liver parenchyme, there has been on increasing awareness of its use in evalution of Liver function. In this study, the diseases of the liver were classified into group A,B,C and D by the liver scanning findings, conventional liver function tests and clinical findings. Following were the results: 1. The colloidal radiogold liver scan appeared normal in the group A, also the albumin in serum, alkaline phosphatase activity and prothrombin time were within normal levels in this group. 2. In the group B, there were acute hepatitis 24(48%), chronic hepatitis 5(10%), toxic hepatitis 3(6%), subacute hepatic necrosis 3(6%), typhoid liver 4(8%), hepatic tuberculosis 2(4%), diabetes mellitus 3(6%) and others 3(6%). In this group, SGOT and SGPT were increased predominantly as compared with group A, and the liver scan showed small amount of mottling of activity and faintly visualized spleen. 3. In the group C, there were postnecrotic liver cirrhosis 30(60%), Laennec cirrhosis 10(20%), cardiac cirrhosis 1(2%), cholangiocarcinoma 1(2%), chronic active hepatitis 6(12%), hepatic milliary tuberculosis 1(2%) and gall bladder cancer 1(2%). In this group, the albumin in serum and prothrombin time were lowered significantly and the liver scan showed severe mottling of activity with extra-hepatic uptake in the spleen and bone marrow along the vertebral column. 4. In the group D, there were primary hepatoma 26(52%), hepatoma with liver cirrhosis 7(14%), metastatic liver cancer 5(10%), liver abscess 10(20%), multiple liver cyst 1(2%) and cystic duct adenoma 1(2%), In this group, the alkaline phosphatase activity was elevated with single or multiple intrahepatic space occupying lesion in the radiogold colloid liver scan.