• The Korean Journal of Nuclear Medicine
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• v.6 no.2
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• pp.21-39
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• 1972

The employment of gamma-ray scintillation camera with the use of short-lived radioisotopic pharmaceuticals, sucu as $^{99m}Tc$ sodium pertechnetate, have enabled us to perform RI (radioisotopic) angiocardiography. Although conventional cardiac catheterization or angiocardiography using contrast media have been an important diagnostic tool, they may carry some risks or serious complications. The author investigated on RI angiocardiography in twelve normal and twenty five patients with cardiovascular diseases in an effort to evaluate its diagnostic value. The results obtained with this study are as follows; 1. In normal subjects, the scintillation camera transit time of arm-to-right heart was found to be $2.1{\pm}0.67$ seconds, right heart-to-lung $1.5{\pm}0.40$ seconds and lung-to-left heart $3.5{\pm}0.86$ seconds. 2. Transformation or displacement of the heart and the great vessel are easily discriminated by RI angiocardiography. Both in the cases with tricuspid atresia and tetralogy of Fallot, ventricular septal defects are well recongnized by sequential RI angiocardiography. 3. It is also helpful in determinining the site and extent of obstruction, and estimatiing the postoperative course both in the cases with superior vena cava syndrome and pulmonary stenosis. 4. Pericarditis with effusion is readilly diagnosed by RI angiocardiogram showing characteristic "dead space" between intracardiac and intrapulmonary radioactivity. 5. It was found that the diagnostic accuracy of this study was 78.4%. It is concluded that above results obtained are useful and accurate enough for the diagnostic screening methode for clinical practice.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.22-27
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• 1993

Drug abuse is widespread in worldwide and has been associated with neurologic complication. Zipeprol is one of the drugs which been abused for psychological satisfaction in some adolescents. This agent is non-opioid antitussive agent, which is not legally considered as being capable of creating dependence or abuse liability at therapeutic serum levels. But it has been reported that acute or chronic overdose create neurologic complication such as convulsion as well as dependence. Recently we experienced six zipeprol abusers who admitted due to convulsion and variable neurologic symptoms. The aim of our study was to determine the role of $^{99m}Tc$-HMPAO brain SPECT in those patients. EEG and brain CT showed no abnormal finding, but brain SPECT showed focal or multiple perfusion abnormalities in frontal, parietal, occipital cortex, basal ganglia, thalamus and especially at temporal cortex. These results suggest that brain SPECT may be a useful diagnostic tool to evaluate the cerebral dysfunction infused by zipeprol abuse.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.420-425
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• 1999

We report a case of hepatopulmonary syndrome defined as a triad of chronic liver disease, increased alveolar oxygen gradient on room air, and intrapulmonary arteriovenous shunting. Chest rediographs showed bilateral, basilar, medium sized reticulonodular opacities. High resolution CT scand showed multiple centrilobular nodules and branching structures in the subpleural lung that suggested dilatation of lung vessels with abnormally large number of visible terminal branches. $^{99m}Tc$-macroaggregated albumin(MAA) perfusion lung scan showed right to left shunt. Contrast echocardiography demonstrated intrapulmonary vascular shunt without intracardiac shunt.

• Nuclear Engineering and Technology
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• v.49 no.4
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• pp.776-780
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• 2017

To avoid imaging artifacts and interpretation mistakes, an improvement of the uniformity in gamma camera systems is a very important point. We can expect excellent uniformity using cadmium zinc telluride (CZT) photon counting detector (PCD) because of the direct conversion of the gamma rays energy into electrons. In addition, the uniformity performance such as integral uniformity (IU), differential uniformity (DU), scatter fraction (SF), and contrast-to-noise ratio (CNR) varies according to the energy window setting. In this study, we compared a PCD and conventional scintillation detector with respect to the energy windows (5%, 10%, 15%, and 20%) using a $^{99m}Tc$ gamma source with a Geant4 Application for Tomography Emission simulation tool. The gamma camera systems used in this work are a CZT PCD and NaI(Tl) conventional scintillation detector with a 1-mm thickness. According to the results, although the IU and DU results were improved with the energy window, the SF and CNR results deteriorated with the energy window. In particular, the uniformity for the PCD was higher than that of the conventional scintillation detector in all cases. In conclusion, our results demonstrated that the uniformity of the CZT PCD was higher than that of the conventional scintillation detector.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.33-38
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• 2018

There are limits to check the lesion as inserting a breast implant patients. So the application of BSGI based on Nuclear Medicine examination has increased. In this study, therefore we confirmed the effect of the image applying to breast implants in Breast Specific Gamma Imaging. We utilized Dilon 6800 BSGI scanner and developed the phantom. The self-development phantom was a rectangular shape of $230{\times}190{\times}80mm$ size and had 5 spheres which consisted of diameters of 10, 13, 17, 22, 28 mm in central part. We injected $^{99m}TcO_4$ into the self-development phantom in the proportion of four to one and made each additional phantom filled with 0.9 % sodium chloride, silicon and paraffin. Each additional phantom was placed between detector and self-development phantom. Each image was acquired five times depending on the type and thickness of the additional phantom. Statistical analysis with SPSS ver.18 was applied. In the test of variation according to the thickness of all additional phantoms, as the phantoms which 0.9% sodium chloride, silicon and paraffin increased, the attenuation variation was higher(P<0.005). There was no significant difference in the attenuation variation and the quality of image for type of the additional phantom. Therefore, if the effect of the image applying to breast implants in Breast Specific Gamma Imaging is confirmed, the higher diagnostic value can be achieved.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.19 no.1
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• pp.54-60
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• 2016

Purpose: The aim of this study is to investigate the association between elevated alanine aminotransferase (ALT) and urosepsis in children with acute pyelonephritis (APN). Methods: We retrospectively identified all children who were managed in our hospital with APN during a decade period. In our study a diagnosis of APN was defined as having a positive urine culture and a positive (99m)Tc-dimercaptosuccinic acid scintigraphy. We compared those with elevated ALT and those with normal ALT according to the following variables: age, gender, duration of fever prior to admission, presence of hypotension, C-reactive protein (CRP), creatinine, presence of anemia, white blood cells count, platelet count, blood culture result, and grades of vesicoureteral reflux. In addition, the correlation between elevated ALT and positive blood culture was analyzed in detail. Results: A total of 996 children were diagnosed with APN, of which 883 were included in the study. ALT was elevated in 81 children (9.2%). In the analysis of demographic characteristics, the number of children with elevated ALT was higher in children between 0 to 3 months, boys, and in those with positive blood culture (p=0.002, 0.036, and 0.010, respectively). In multivariate analysis of variables associated with positive blood culture, age younger than 3 months, elevated ALT, elevated CRP, and elevated creatinine showed statistical significance (p=0.004, 0.030, 0.043, and 0.044, respectively). Conclusion: Our study demonstrates the association between elevated ALT and increased prevalence of urosepsis in addition to elevated CRP, elevated creatinine, and age younger than 3 months in children with APN.

• The Korean Journal of Nuclear Medicine
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• v.16 no.1
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• pp.49-54
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• 1982

For this study, the authors obtained and examined anterior views of the liver and spleen in two different positions, upright and supine, of 39 normal subjects and 20 patients with hepaticpathology by means of $^{99m}Tc-colloid$ and gamma camera. This examination confirms the following findings. In general, it is shown, left lobe of the liver in upright position becomes longer in height than in supine position, while the distance between lateral margin of the liver and that of the spleen becomes father in with in supine position than in upright position. The upper margin of liver moves more downward in upright position than in supine. It is noticeable that as for 5 cases with severe chronic liver disease, there is minimal alteration of the liver shape between in two positions. The comparison of the both positions for the better liver scan shows the following finding. Prominent caudate and/or left lobe are marked in the upright position in 16 cases out of the total 59, while none is found in the supine. The false cold area in lower part of the liver disappears in 7 cases in the upright position, while only one shows the disappeance of the false cold area in the supine. Left liver margin due to close contact of spleen is blurred in 3 cases in the upright position. In total 23 cases out of 59 support that the upright position is better for the liver scan, while only 4 cases support the supine position is better. These findings support two assumptions. One is that upright view can bo expected more improved resoluton than supine view for liver scan. Second is that minimal change of the liver shape in both views indicate the serious abnormality in the liver.

• The Korean Journal of Nuclear Medicine
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• v.24 no.1
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• pp.119-123
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• 1990

Unexpected renal abnormality can be detected on bone scan using Tc-99m-MDP. The purpose of the study is to evaluate the diagnostic significance of diffusely increased bliateral renal uptake on bone scarf. 1,500 boor scan were reviewed and 43 scans which showed diffusely increased bliateral renal uptake were selected for analysis. Laboratory findings for renal and liver function tests including routine urinalysis were reviewed in 43 patients. 26 of 43 case showed abnormality in urinalysis and renal function stud 20 of 43 cases showed abnormal liver function study and 3 of these cases were diagnosed as hepatorenal syndrome later. 13 of those 20 cases had liver cirrhosis with or without hepatoma. 12 of 43 cases showed abnormality both in renal and liver function studies. 2 of 43 cases showed diffusely increased bilateral renal uptake after chemotherapy for cancer but not on previous scans before chemotherapy. 2 of 43 cases showed hypercalcemia and 8 of 43 cases had multifocal bone uptake due to metastasis or benign bone lesion. but the latter showed no hypercalcemia at all. There was no significant correlatrion between increased renal uptake and MDP uptake in soft tissue other than kidneys. This study raised the possibility that the impaired liver and/or renal function may result in diffuse increase of bliateral renal uptake of MDP of unknown mechaninsm. It seems to need further study on this correlation.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.145-151
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• 2000

The present study was performed to investigate the relationship between the salivary flow rate and the interpretation results of salivary scan in the patients with dry mouth. Twenty-five patients with dry mouth who visited the Dept. of Oral Medicine & Oral Diagnosis, Seoul National University Dental Hospital, were included. The unstimulated whole salivary flow rate was determined by the spitting method and the stimulated whole salivary flow rate was measured with gum-base chewing. Salivary scan was performed after the infusion of $^{99m}technetium$ pertechnetate(Tc) and interpreted. The obtained results were as follows: 1. The unstimulated and stimulated whole salivary flow rate were significantly decreased compared to normal value, which reflected the extensive destruction of salivary gland function in the patients with dry mouth. 2. The unstimulated and stimulated whole salivary flow rate were decreased in the group with decreased function in salivary scan compared with the group with normal function in salivary scan. However, there was no statistical significance between groups. 3. The difference between the stimulated and unstimulated whole salivary flow rates was greater in the group with normal function in salivary scan compared with the group with decreased function in salivary scan. 4. There was significant positive correlation between the stimulated and unstimulated whole salivary flow rates. The level of correlation was higher in the group with decreased function in salivary scan than the group with normal function in salivary scan. Collectively, these data suggested that salivary scan had the limited value. The comprehensive evaluation including history taking, clinical examination, clinical laboratory as well as the measurement of salivary flow rate are need for patients with dry mouth.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.325-330
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• 2011

To predict the details of flow in industrial process unit, single photon emission computed tomography (SPECT) is a promising technique. Recently, industrial SPECT based on medical system has developed by researchers of the Korea Atomic Energy Research Institute (KAERI) and Hanyang University. In the present study, to confirm the effect of the number of detectors on image quality, and determine the optimal number of detectors in industrial SPECT, industrial SPECT system with various geometries were evaluated by the Monte Carlo simulation. CsI(Tl) detectors ($12mm{\times}12mm{\times}20mm$) with collimators (the geometric resolution of collimator $R_g$ was 4 cm at the center of the 30 cm diameter cylindrical vessel object) were modeled in a hexagonal array, and the point sources of $^{99m}Tc$, $^{68}Ga$, and $^{137}Cs$ were simulated at the center of the cylindrical vessel object using the MCNPX code. Then, the reconstruction images of each geometry were reconstructed using the expectation maximization (EM) algorithm. In this study, the reciprocity theorem was used to improve computation time required for system matrix of the EM algorithm. The result shows that the resolution of the reconstructed image was significantly improved by increasing the number of detectors in industrial SPECT system and more than 60 detectors will be required for the resolution of the reconstructed image.