• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.314-322
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• 2008

Purpose: It is widely recognized that good quality control (QC) program is essential for adequate imaging diagnosis using gamma camera. The purpose of this study is to survey the current status of QC of gamma cameras in Republic of Korea for implementing appropriate nationwide quality control guidelines and programs. Methods: A collection of data is done for personnel, equipment and appropriateness of each nuclear medicine imaging laboratory's quality control practice. This survey is done by collection of formatted questionnaire by mails, emails or interviews. We also reviewed the current recommendations concerning quality assurance by international societies. Results: This survey revealed that practice of quality control is irregular and not satisfactory. The irregularity of the QC practice seems due partly to the lack of trained personnel, equipment, budget, time and hand-on guidelines. Conclusion: The implementation of QC program may cause additional burden to the hospitals, patients and nuclear medicine laboratories. However, the benefit of a good QC program is obvious that the hospitals can provide good quality nuclear medicine imaging studies to the patients. It is important to use least cumbersome QC protocol, to educate the nuclear medicine and hospital administrative personnel concerning QC, and to establish national QC guidelines to help each individual nuclear medicine laboratory.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.3-11
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• 2015

Purpose It is hard to obtain high quality images of knee and T.M joint because of a lot of soft tissues in the knee and T.M joint area. Most conventional system for high resolution scintigraphy was used by 4 mm aperture pinhole collimator. Performance comparison of high-resolution pinhole SPECT for Micro deluxe phantom using conventional system. the aim of this study is to evaluate performance of each aperture according to the diameter size and the usefulness of 24-hour delayed bone scintigraphy. Materials and Methods In this study 6 mm, 8 mm diameter pinhole collimators were mounted on Siemens E.CAM systems. In order to evaluate performance evaluation of each aperture and Micro Deluxe phantom was used for performance comparison of conventional SPECT system, Projection data were obtained with 9 degree increment per 30 second. Transverse images were reconstructed using dedicated OSEM algorithm with recovery of detector blurring. $^{99m}Tc-HDP$ source was used for 24-hour delayed bone scintigraphy. Results The knee joint images obtained with 24-hour delay were improved more than those obtained with 3-hour delay in our study. The 6 mm and 8 mm pinhole collimators FWHM have improved by 28% SNR and Uniformity have improved by 35%, Contrast has improved by 7% in 24-hour delayed knee joint image. While in 24-hour delayed T.M joint image of the 6 mm and 8 mm pinhole collimators FWHM have decreased by 60% SNR has decreased by 20% and Uniformity has decreased by 25%, Contrast has decreased significantly. Conclusion Pinhole collimators with 6 mm and 8 mm diameter could offer a superior performance for 24-hour delayed bone scintigraphy. The use of 24-hour delayed image provides additional benefits for pinhole scintigraphy of knee joint. Therefore, we expect that it is useful for precise diagnosis of knee joint and it is applicable to others joint imaging.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.15-22
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• 2017

Purpose During Brain SPECT study, critical factor for proper study with $^{99m}Tc-ECD$ or $^{99m}Tc-HMPAO$ is one of the important causes to patent's movement. It causes both improper diagnosis and examination failure. In this study, we evaluated the effect of Dynamic Continuous Mode Acquisition compared to Step and Shoot Mode to raise efficacy and reject the data set with movement, as well as, be reconstructed in certain criteria. Materials and Methods Deluxe Jaszczak phantom and Hoffman 3D Brain phantom were used to find proper standard data set and exact time. Step and Shoot Mode and Dynamic Continuous Mode Acquisition were performed with SymbiaT16. Firstly, Deluxe Jaszczak phantom was filled with $Na^{99m}TcO_4$ 370 MBq and obtained in 60 minutes to check spatial resolution compared with Step and Shoot Mode and Dynamic Continuous Mode. The second, the Hoffman 3D Phantom filled with $Na^{99m}TcO_4$ 74 MBq was acquired for 15 Frame/minutes to evaluate visual assessment and quantification. Finally, in the Deluxe Jaszczak phantom, Spheres and Rods were measured by MI Apps program as well as, checking counts with the frontal lobe, temporal lobe, occipital lobe, cerebellum and hypothalamus parts was performed in the Hoffman 3D Brain Phantom. Results In Brain SPECT Study, using Dynamic Continuous Mode rather than current Step and Shoot Mode, we can do the reading using the 20 to 50 % of the acquired image, and during the test if the patient moves, we can remove unneeded image to reduce the rate of restudy and reinjection. Conclusion Dynamic Continuous Mode in Brain study condition enhances effects compared to Step and Shoot Mode. And also is powerful method to reduce reacquisition rate caused by patient movement. The findings further indicate that it suggest rejection limit to maintain clinical value with certain reconstruction factors compared with Tomo data set. Further examination to improve spatial resolution, SPECT/CT should be the answer for that.

• Journal of Nutrition and Health
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• v.52 no.6
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• pp.559-568
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• 2019

Purpose: This study examined the prevalence of food allergies and allergenic factors in a selected sample of children living in Seoul, Korea, along with their dietary habits, environmental factors, and diseases as risk factors for food allergy. The results of this study will provide basic data for addressing food allergies. Methods: We selected 3,004 pre-school and school-age children, aged 0 ~ 12, in the 25 districts of Seoul as the study sample. Structured self-report questionnaires were administered over a two-month period in July-August 2018, and the children's parents recorded the answers on their children's behalf. The research tools in this study included the Korean version of the questionnaire from the International Study of Asthma and Allergies in Childhood (ISAAC). Results: The physician-diagnosed prevalence rate of food allergies was 14.2%, while 20.4% of the children experienced allergic symptoms at least once and 17.4% reported symptoms within the previous 12 months. The children's symptoms included skin problems (88.1%), gastrointestinal issues (19.2%), oral issues (16.7%), respiratory issues (12.7%), and systemic issues (1.3%). The causes of allergies included eggs, peaches, milk, peanuts, and shrimps. The factors influencing the experience of food allergies were the consumption of cereal (aOR, 1.52; 95% CI, 1.09 ~ 2.10; p = 0.013), potatoes (aOR, 1.88; 95% CI, 1.33 ~ 2.65; p < 0.001), and fast food (aOR, 1.73; 95% CI, 1.10 ~ 2.72; p = 0.017). Having food allergy symptoms was associated with a higher risk of experiencing asthma (aOR, 4.22 95% CI, 3.10 ~ 5.76; p < 0.001), allergic rhinitis (aOR, 2.53; 95% CI, 2.03 ~ 3.15; p < 0.001), and atopic dermatitis symptoms (aOR, 3.56; 95% CI, 2.88 ~ 4.40; p < 0.001). Conclusion: Episodes of food allergies warrant examining regular food consumption and placing dietary restrictions through early diagnosis as these episodes may imply the presence of other allergies. Our findings offer basic insights into the patterns, prevalence and symptoms of children's food allergies in Seoul, and our findings will contribute to identifying effective interventions for food allergies.

• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1001-1008
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• 2018

Purpose: To compare the success rates between silicone tube intubation using a lacrimal endoscope and using a conventional nasal endoscope alone in adult patients suffering from epiphora. Methods: We conducted a retrospective chart review of 80 eyes of 55 patients who underwent silicone tube intubation from January 2014 to June 2017. Patients were preoperatively diagnosed with syringing and dacryocystography. The silicone tube was removed 3 months after surgery and success rates were evaluated at 4 and 12 months. Success rates were analyzed by dividing the patients into two groups, according to lacrimal endoscope use. Results: A lacrimal endoscope was used in 40 eyes. In the group using a lacrimal endoscope, preoperative diagnoses were partial obstruction in 26 eyes and complete obstruction in 14 eyes. In the group without lacrimal endoscope use, preoperative diagnoses were partial obstruction in 35 eyes and complete obstruction in 5 eyes (p = 0.018). The success rates at 4 and 12 months after surgery in the two groups (with and without lacrimal endoscope use) were 87.5% and 80.0% and 72.0% and 62.1% (p = 0.546 and p = 0.565), respectively. The success rates of patients with partial obstruction in the two groups were 92.3% and 82.9% at 4 months and 71.4% and 69.2% at 12 months (p = 0.448 and p = 1.000), respectively. The success rates of patients with complete obstruction in the two groups were 78.6% and 60.0% at 4 months and 72.7% and 33.3% at 12 months (p = 0.570 and p = 0.505), respectively. Site differences, the degree of obstruction, and lacrimal endoscope use had a significant impact on the success rate at 4 and 12 months (p = 0.001 and p = 0.022, respectively). Conclusions: Although silicone tube intubation using a lacrimal endoscope cannot guarantee a significant success rate, it is possible to observe the anatomical structure of the nasolacrimal pathway in real time, such that the appropriate diagnosis and treatment can be performed simultaneously. Because patients diagnosed as having a complete obstruction had a good success rate, we can extend indication of silicone tube intubation as a less invasive approach.

• Laboratory Medicine Online
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• v.6 no.1
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• pp.25-30
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• 2016

Background: The cell cycle-dependent enzyme thymidine kinase 1 (TK1) is known to increase during cancer cell proliferation and has been reported as a prognostic marker for various hematologic malignancies and solid tumors. This study aimed to determine the reference interval in Korean healthy controls and to evaluate the usefulness of TK1 as a biomarker for aggressive clinical behavior in B-cell lymphoma patients. Methods: We enrolled 72 previously untreated patients with B-cell lymphoma and 143 healthy controls. Serum TK1 levels were measured by chemiluminescence immunoassay ($Liaison^{(R)}$, DiaSorin, USA). We established the reference intervals in healthy controls. The diagnostic performance of serum TK1 was studied using receiver operating characteristic (ROC) analysis, and the correlation between the cutoff level for serum TK1 and clinical characteristics of B-cell lymphoma was evaluated. Results: The reference range (95th percentile) of serum TK1 in healthy controls was 5.4-21.8 U/L. There was a clear difference in TK1 levels between patients with B-cell lymphoma and healthy controls ($40.6{\pm}68.5$ vs. $11.8{\pm}4.4U/L$, P <0.001). The area under the curve of serum TK1 for the diagnosis of B-cell lymphoma was 0.73 (cutoff, 15.2 U/L; sensitivity, 59.7%; specificity, 83.2%). An increased TK1 level (${\geq}15.2U/L$) correlated with the advanced clinical stage (P <0.001), bone marrow involvement (P =0.013), international prognostic index score (P =0.001), lactate dehydrogenase level (P =0.001), low Hb level (<12 g/dL) (P =0.028), and lymphocyte count (P =0.023). Conclusions: The serum TK1 level could serve as a useful biomarker for aggressive clinical behavior in B-cell lymphoma patients.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.1
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• pp.74-82
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• 2016

Objectives : Suicide attempters have impaired decision making and are at high risk of reattempt. Therefore it is important to refer them to psychiatric treatment. Especially, People with medical comorbidity are at higher risk of suicidal attempt and mortality. The aim of this study was to investigate the characteristics of suicidal attempters and to analyze the influence of the medical comorbidity on decision to receive psychiatric treatment after visit to an emergency department. Methods : One hundred and thirty two patients, who visited the emergency room of a general hospital in Gyeonggi-do between January, 2012 and December, 2012 were enrolled as the subjects of this study. After reviewing each subject's medical records retrospectively, demographic and clinical factors were analyzed. Results : Regardless of the engagement type, either via admission or outpatient clinic, the determinant factors of psychiatric treatment engagement were psychiatric diagnosis, employment status, previous psychiatric treatment history, and previous attempt history. Comparison of severity of medical comorbidity(Charlson Comorbidity Index) showed that suicide attempters who received psychiatric treatment via admission or refused the treatment tended to have higher level of medical comorbidity than who received psychiatric treatment via outpatient department. Conclusions : Our findings showed that medical comorbidity of suicide attempters affected the decision to accept psychiatric treatment. All psychiatrists should evaluate the presence and the severity of medical comorbidity of the suicide attempters and consider implementing more intervention for the medically ill attempters who are willing to discharge against advice.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.3
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• pp.271-280
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• 2021

Purpose. The aim of this study was to evaluate the relationship between the patient's occlusion and a cracked tooth by using T-scan occlusal analysis and a quantitative light-induced fluorescence (QLF) technology. Materials and methods. This study was carried out on 51 patients having cracked teeth between January, 2019 and December, 2020. The tooth crack was determined with a Q-ray pen and QLF parameters (ΔF_max and ΔR_max) were obtained by a Q-ray software. T-scan tests were conducted to all subjects and then, the occlusal force and disclosing time were analyzed. Mann-Whitney U test was performed to compare the occlusal force and disclosing time between cracked teeth groups and contra-lateral normal teeth groups (α = .05). Mann-Whitney U test was performed to compare ΔF_max and ΔR_max according to the results of cold/bite tests (α = .05). A Spearman correlation analysis was run to determine the relationship between ΔF_max or ΔR_max and occlusal force or disclosing time (α=.05). Results. The mean occlusal force and disclosing time were significantly higher on cracked teeth than on normal teeth (P < .05). The ΔF_max or ΔR_max were not significantly different according to the results of cold/bite tests (P > .05). There was no correlation between ΔF_max or ΔR_max and occlusal force or disclosing time (P > .05). Conclusion. There was a significant relationship between occlusion and cracked tooth syndrome. QLF has the potential to be a valuable tool for the diagnosis of tooth crack in clinical practice.

• Sleep Medicine and Psychophysiology
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• v.26 no.1
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• pp.44-48
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• 2019

Objectives: Insomnia is one of the most prevalent sleep disorders. Recent studies suggest that cognitive and physical arousal play an important role in the generation of primary insomnia. Studies have also shown that information processing disorders due to cortical hyperactivity might interfere with normal sleep onset and sleep continuity. Therefore, focusing on central nervous system arousal and normalizing the information process have become current topics of interest. It has been well known that neurofeedback can reduce the brain hyperarousal by modulating patients' brain waves during a sequence of behavior therapy. The purpose of this study was to investigate effects of neurofeedback therapy on electroencephalography (EEG) characteristics in patients with primary insomnia. Methods: Thirteen subjects who met the criteria for an insomnia diagnosis and 14 control subjects who were matched on sex and age were included. Neurofeedback and sham treatments were performed in a random order for 30 minutes, respectively. EEG spectral power analyses were performed to quantify effects of the neurofeedback therapy on brain wave forms. Results: In patients with primary insomnia, relative spectral theta and sigma power during a therapeutic neurofeedback session were significantly lower than during a sham session ($13.9{\pm}2.6$ vs. $12.2{\pm}3.8$ and $3.6{\pm}0.9$ vs. $3.2{\pm}1.0$ in %, respectively; p < 0.05). There were no statistically significant changes in other EEG spectral bands. Conclusion: For the first time in Korea, EEG spectral power in the theta band was found to increase when a neurofeedback session was applied to patients with insomnia. This outcome might provide some insight into new interventions for improving sleep onset. However, the treatment response of insomniacs was not precisely evaluated due to limitations of the current pilot study, which requires follow-up studies with larger samples in the future.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.3
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• pp.78-86
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• 2018

Purpose: We aimed to delineate clinical spectrum and short-term effects after enzyme replacement therapy (ERT) for 5 mucopolysaccharidosis type II (MPS II). Methods: Five patients were diagnosed with MPS II by clinical findings, enzyme activity, and genetic testing. Idursulfase was administered by intravenous infusion at a dose of 0.5 mg/kg every week. Observational chart analysis of patients, who underwent systematic investigations more than 12 months after initiation of ERT was done retrospectively. Results: Three patients were classified as having the attenuated type, and 2 patients were classified as having the severe type. The median age at the diagnosis was 9.6 years (range 3.4-26 years). Four different mutations in 5 Korean patients (4 families) with MPS II were identified, among which two were novel mutations (1 small insertion mutation: p.Thr409Hisfs*22, and 1 missense mutation: p.Gly134Glu). Two severe type sibling patients with the same mutation had different clinical manifestation. Urinary glycosaminoglycan excretion decreased within the twelve months of ERT (P=0.043). Liver and spleen volumes showed reductions that were maintained in all patients (P=0.043 and P=0.043, respectively). Improvements were also noted in left ventricular mass index (P=0.042), shoulder flexion (P=0.043), shoulder abduction (P=0.039), knee flexion (P=0.043), elbow flexion (P=0.042), and respiratory distress index (P=0.041). Conclusion: This study demonstrates that Korean patients with MPS II are clinically heterogeneous and indicates that idursulfase is relatively effective in several clinical parameters including heart size and respiratory distress index without infusion-related reactions in patients with MPS II.