• Childhood Kidney Diseases
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• v.4 no.2
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• pp.92-101
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• 2000

Purpose : We analyzed the demogaphic data md clinical course of Korean children with chronic renal failure (CRF) observed between 1990 and 1999. Patients and Methods : Questionnaires were mailed to all children's hospitals ail through the country. We asked for primary renal disease age and serum creatinine levels at first presentation with CRF and end-stage renal disease (ESRD), and modes of renal replacement therapy (RRT). Results : 401 children (254 boys, 147 girls) with CRF, defined as a permanent increase of serum creatinine above 1.2 mg/dl for at least 3 months or until death, were identified. This represents an incidence of 3.68 per million child population per year. Of these patients, 22$\%$ on younger than 5 years, 28$\%$ 5 to 10 years and 50$\%$ 10 to 15 year. Eight five $\%$ of the patients could be classified with a primary renal disease. The most frequent cause is glomerulonephritis (36$\%$), followed by chronic pyelonephritis (21$\%$), renal hrpo/dylplasia (9$\%$), and hereditary nephropathies (7$\%$). Reflux nephropathy (16$\%$) was the most common single cause of CRF. ESRD was reached in 70$\%$ of all patient. 99.3$\%$ of these started RRT. Hemodialysis (HD, 42$\%$), peritoneal dialysis (PD, 35$\%$) and transplantation (TP, 23$\%$) were performed as the initial mode of RRT. A total of 161 TPs were performed (159 first grafts, 2 second grafts). A total of 32 patients died. The main causes of death were dialysis related complication in HD patients and infections in PD patients. Survival rate on any form of RRT was 88.7$\%$ during the mean follow-up period of 37 months. Conclusion Major efforts should be directed toward earlier diagnosis and treatment of reflux nephropathy to prevent occurrence of Of. Dialysis and TP have now become well accepted forms of treatment in Korean children with ESRD.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.9-17
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• 2017

A high degree of precision and accuracy in Gamma Knife Radiosurgery(GKRS) is a fundamental requirement for therapeutical success. Elaborate radiation delivery and dose gradients with the steep fall-off of radiation are clinically applied thus necessitating a dedicated Quality Assurance(QA) program in order to guarantee dosimetric and geometric accuracy and reduce all the risk factors that can occur in GKRS. In this study, as a part of QA we verified the accuracy of single-shot dose profiles used in the algorithm of Gamma Knife Perfexion(PFX) treatment planning system employing Variable Ellipsoid Modeling Technique(VEMT). We evaluated the dose distributions of single-shots in a spherical ABC phantom with diameter 160 mm on Gamma Knife PFX. The single-shots were directed to the center of ABC phantom. Collimating configurations of 4, 8, and 16 mm sizes along x, y, and z axes were studied. Gamma Knife PFX treatment planning system being used in GKRS is called Leksell GammaPlan(LGP) ver 10.1.1. From the verification like this, the accuracy of GKRS will be doubled. Then the clinical application must be finally performed based on precision and accuracy of GKRS. Specifically the width at the 50% isodose level, that is, Full-Width-of-Half-Maximum(FWHM) was verified under such conditions that a patient's head is simulated as a sphere with diameter 160mm. All the data about dose profiles along x, y, and z axes predicted through VEMT were excellently consistent with dose profiles from LGP within specifications(${\leq}1mm$ at 50% isodose level) except for a little difference of FWHM and PENUMBRA(isodose level: 20%~80%) along z axis for 4 mm and 8mm collimating configurations. The maximum discrepancy of FWHM was less than 2.3% at all collimating configurations. The maximum discrepancy of PENUMBRA was given for the 8 mm collimator along z axis. The difference of FWHM and PENUMBRA in the dose distributions obtained with VEMT and LGP is too small to give the clinical significance in GKRS. The results of this study are considered as a reference for medical physicists involved in GKRS in the whole world. Therefore we can work to confirm the validity of dose distributions for all collimating configurations determined through the regular preventative maintenance program using the independent verification method VEMT for the results of LGP and clinically assure the perfect treatment for patients of GKRS. Thus the use of VEMT is expected that it will be a part of QA that can verify and operate the system safely.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.363-372
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• 1997

One hundred forty-four patients underwent operation for coarctation of the aorta at Seoul National University Children's Hospital between June 1986 and Decembsr 1995. Age ranged 0.1 to 191 months. Of these 78.5%(113) were infants. We classified the patients in terms of the anatomic location of coarctatiln and the associatCd anomalies(I[401= primary coarctation, 11(741=isthmic hypoplasia, lIIf30)=tubular hypoplasia involving transverse arch, Ar63 =with ventricular septal defect, B(28)=with other major cardiac defects). Subcalvian flap coarctoplasty(60), resection & anastomosis(44), extended aortoplasty(26), and onlay patch(14) were used as surgical methods. Overall operative mortality was 16.0(23/144)%. The hospital mortality was signific'antly higher in patheints with type 111, subtype B, younger age(under 3 months), extended aortoplasty(p(0.01). However, one-stage total repair in patients with subtype A or B were not found to be a predictor of hospital death. Restenosis had occured in 18 patients among 121 survivals(14. 9%). The mean follow-up period was 29.1 $\pm$28.8(0~129.2) months. Preoperative, immediate postoperative(within 3 months after operation) and postoperative(later than 6 months after operation) echocardiographic data on the dimensions of ascending aorta(AA), transverse arch(TA), an4 aortic isthmus(Al) were available in 77 patients(I=20, ll=42, 111= 15). Preoperative and postoperative aortic isthmus(All) and tra sverse arch indices(TAI), defined as TAIAA & AIIAA respectively, were compared. Immediate postoperative All in type 1, II and TAI in type 111 were significantly smaller in stenotic than non-stenotic group suggesting incomplete relieves of stenotic segment Younger age, subclavian coarctoplasty in patient under 3 months of age were round to be the risk factors for restenosis in this series. In conclusion, We found that aortic arch index and transverse arch index can be a useful tool to figure out the anatomic and clinical characteristics of the patients with aortic coarctation, and that anatomy, associated anomalies, age, and surgical methods may influence the surgical outcome of the coarctation repair.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.44-48
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• 2008

Purpose: In FDG-PET/CT of breast cancer, a sensitivity was 80~96% and a specificity was 75~95% commonly. It was valuable to identify a cancer in early stage been difficult in Mammography. Most of the PET/CT scans have been examined on supine position, so, the image of breast has been acquired by reconstructed whole body scan image. However, using prone position with a compensator, a shape of breast was reassembly shown to be real by gravity. Therefore, the purpose of this study was to evaluate diagnostic value of prone position in FDG PET-CT of breast cancer. Materials and Methods: 30 female patients with doubtful or positive breast cancer were examined. The PET-CT whole body scan was acquired at 60 minutes after $^{18}F$-FDG injection on Supine position. Then, regional breast spot scan was progressed on prone position using a compensator. Each image was evaluated by physicians blinded to patient's data, and statistical analysis did through SUVs measured in PET-CT images. Results: In 27 of 30 patients, prone position was shown accurate discrimination and diagnostic value, but in another 3 patients had a lesion 1cm below, PET-CT couldn't detect it, unlike MRI. Consequently, prone position distinguished a lesion better than Supine position, because of low degree of metamorphosis by gravity. The SUVs analysis of each position was significant (p value=0.004). Conclusion: In PET-CT of breast cancer, prone position could detect micrometastasis as well as primary lesion, better than supine position. Therefore, this study proposes that any technical change considered morphological feature like prone position can offer adequate and useful diagnostic information, together with complementary quantitative analysis.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.320-329
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• 1997

Neuroanatomic substrate of autism has been the subjects of continuing investigation. Because previous studies had not demonstrated consistent and specific neuroimaging findings in autism and most studies comprised adults and school-aged children, we performed a retrospective review in search of common functional and anatomical abnormalities with brain SPECT using Tc-99m ECD and correlative MRI The patient population was composed of 18 children aged 28 to 89 months(mean age : 55 months) who met the diagnostic criteria of autism as defined in the DSM-IV and CARS. Brain SPECT was performed after intravenous injection of 185-370MBq of Tc-99m ECD using brain dedicated annular crystal gamma camera. MRI was performed in all patients including T1, T2 axial and T1 sagittal sequences. SPECT data were visually assessed. Thirteen patients had abnormal SPECT scan revealing focal areas of decreased perfusion. Decreased perfusion of cerebellar vermis(12/18), cerebellar hemisphere(11/18), thalami(13/18), basal ganglia(4/18), posterior parietal(7/18), and temporal(4/18) area were noted on brain SPECT. Whereas, only 3 patients had abnormal MR findings which were subtle volume loss of parieto-occipital white matter in 3 and mild thinning of posterior body of corpus callosum in 2 and slightly decreased volume of cerebellar vermis in 1. Comparison of the numbers of abnormal findings revealed that regional cerebral blood flow (rCBF) abnormalities seen on SPECT were more numerous than anatomical abnormalities seen on MRI. In conclusion, extensive perfusion impairment involving cerebellum, thalami and parietal lobe were found in this study. SPECT may be more sensitive in reflecting pathophysiology of autism than MRI. However, further studies are mandatory to determine the significance of thalamic and parietal perfusion impairment in autism.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.158-175
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• 2005

Statement of problem. Every effort has been continually made to obtain objectivity in measuring the longevity of fixed restorations, such as by establishing unified judgement standard for deciding success and adopting statistical method that analyzes the data of successful and failed cases at the same time. In Korea, however desired level of development has not to be made in this field yet. Purpose. This study, adopting California Dental Association (CDA) quality evaluation system, established objective standard for deciding success, and inferred the longevity of fixed restorations and their failure analysis through adopting Kaplan-Meier survival analysis. Material and method. In order to assess the longevity of flxed restorations serviced in Korea and causes of failure, a total of 1109 individuals (aged 15-74, 716 women and 393 men loaded with 2551 unit fixed restorations, and 1934 abutments) who lived in Kyung-In Province were examined and the findings were as follows : Results. 1. Length of service of fixed restorations serviced in Korea was 6.86$\pm$0.15 yr (mean), 5.5 yr (median), and the rate of success was 65.82% in 5 year survival, and 21.15% in 10 year survival. 2. When there was patient's need for replacing old prosthetics, longevity of fixed restorations was 7.51$\pm$0.27 yr (mean), 7 yr (median), and the rate of success was 61.08% in 5 year survival, and 17.57% in 10 year survival. 3. Longevity of fixed restorations was longest in the over-sixty age group(9.21$\pm$0.66) and that of the teen age group(3.39$\pm$0.28) was shortest (p<0.05). 4. Longevity of fixed restorations of women (7.38$\pm$0.18 years) was longer than that of men (6.00$\pm$0.26) (p<0.05). 5. As for the provider factor (such as unlicensed performers, university hospitals, and private clinic), there was no statistically significant difference in longevity of fixed restorations. 6. Defective margin (34.78%). periodontal disease (12.15%), periapical involvement (11.73%), was the most frequent causes of failure and poor esthetics group showed the longest life above all (p<0.05). Actual frequent causes of failure after removing old prosthetics were defective margin, periapical involvement, periodontal disease and uncemented restoration. In 75.67% of the cases, abutment state after removing old prosthetics was good enough for loading another prosthetics. 7. There was found to have statistically significant influence between longevity of single crown (6.35$\pm$0.20 yr) and that of 3 unit fixed restorations (7.60$\pm$0.30 y) (p<0.05). In each case the most frequent cause of failure was defective margin. 8. The number of cantilever pontic, pontic/abutment ratio, oral hygiene status were found to have no statistically significant influence on longevity of fixed restorations in all groups (p>0.05). 9. Longevity of fixed restorations made of non precious metal was longest (9.60$\pm$0.40 yr) semi precious and precious trailing behind(p<0.05). 10. Group function group (37.04%) and partial group function group (44.62%) were predominant in frequency but showed no correlation between them and among different types of occlusal plane and different types of occlusal surface (p>0.05). 11. Longevity of fixed restorations was longest in the centric interference group(9.35$\pm$0.62) (p<0.05) among different types of occlusal interference. Conclusion. We found that longevity of fixed restorations serviced in Korea is affected by age, gender and type of material, and that most frequent cause of failure is defective margin. In order to assess the accurate longevity of axed restorations, unified research design. overcoming inter-observer difference and establishing the objective research items are needed. Furthermore, it is thought that prospective approach through thorough study and regular follow-ups is needed just from the start of research. Nationwide detailed studies on length of service of fixed restorations manufactured in Korea are hoped to be conducted hereafter.

• Sleep Medicine and Psychophysiology
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• v.11 no.1
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• pp.37-43
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• 2004

Objective: The purpose of this paper is to study the possible differences in clinical and polysomnographic findings, depending on the presence or absence of subjective complaints of abnormal sleep behavior, in patients with RWA on polysomnography. Method: We reviewed patient records and polysomnographic data of patients referred to the Sleep Laboratory at Seoul National University Hospital from June 1996 through October 2002. We defined the manifest RBD group (n=32) as patients having both complaints of abnormal sleep behavior and RWA on polysomnography. The latent RBD group (n=20) consisted of patients who exhibited RWA on polysomnography but did not complain of abnormal sleep behavior. The clinical characteristics and polysomnographic findings between the two groups were compared and analyzed. Results: Fifty-two subjects had RWA, as detected by polysomnography (42 males and 10 females, mean age of $55.1{\pm}19.1\;years$). Subjects in the manifest RBD group were significantly older than those in the latent RBD group ($61.59{\pm}13.5$ vs. $44.70{\pm}2.76\;years$, independent t-test, p<0.01). More subjects in the manifest RBD group exhibited abnormal REM behavior on polysomnography than did subjects in the latent RBD group (81.3 vs. 50.0%, Fisher's exact test, p<0.05). No significant differences between the groups were found in the prevalence of brain disorders and primary sleep disorders, gender proportion, and sleep architecture. Conclusion: No difference in sleep architecture was found between the manifest and the latent RBD groups. Only age and the presence of abnormal sleep behavior on polysomnography differentiated the two groups. We suggest that RWA on polysomnography without complaints of abnormal sleep behavior may be early manifestation of manifest RBD. Attention to RWA on polysomnography is necessary to help prevent full-blown RBD from developing.

• Journal of agricultural medicine and community health
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• v.38 no.2
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• pp.130-141
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• 2013

Objectives: The purpose of this study was to reconsider the necessity of stroke-related educational programs by investigating early symptoms of stroke that emergency medical technicians (EMTs) may experience. Methods: An interview survey was carried out, targeting all EMTs 298 people who were working at 119 fire safety centers and local units in Jeollabuk-do province, from April 1 to 30, 2011. An interviewer administered questionnaire was used to obtain data on ETMs' demographic characteristics, educational level on stroke, and awareness level about early symptoms of stroke and treatment-related characteristics of stroke patients. Results: The results showed that 63.2% of those surveyed had completed the required educational programs on stroke during the past year. The level of awareness about early symptoms of stroke and assessment of stroke patients' condition was relatively high for women, those who were 30 years under, low position people, emergency service practitioners, emergency medical technicians, and people who have completed education, respectively. It was also turned out that 82.8% of those surveyed took stroke patients to the nearest hospitals first so that they could receive appropriate treatment. The level of awareness about early symptoms of stroke and assessment of stroke patients' condition in people who have completed education were higher than non-complete. The level of awareness about early symptoms of stroke was positively correlated with confidence, satisfaction and appropriateness in treatment of stroke patients. Conclusions: These results strongly suggest that it is necessary to operate specialized educational programs to enhance EMTs' appropriate awareness of the early symptoms of stroke and assessment of stroke patient's condition.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.583-591
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• 1997

The functional derangement of skeletal muscles which may be attributed to chronic hypoxia has been accepted as a possible mechanism of exercise impairment in patients with chronic obstructive pulmonary disease (COPD). The metabolic changes in skeletal muscle in patients with COPD are characterized by impaired oxidative phosphorylation, early activation of anaerobic glycolysis and excessive lactate and hydrogen ion production with exercise. But the cause of exercise limitation in patients with chronic lung disease without hypoxia has not been known. In order to evaluate the change in the skeletal muscle metabolism as a possible cause of the exercise limitation in chronic lung disease patients without hypoxia, we compared the muscular metabolic data of seven male patients which had been derived from noninvasive $^{31}P$ magnetic resonance spectroscopy(MRS) with those of five age-matched normal male control persons. $^{31}P$ MRS was studied during the sustained isometric contraction of the dominant forearm flexor muscles up to the exhaustion state and the recovery period. Maximal voluntary contraction(MVC) force of the muscle was measured before the isometric exercise, and the 30% of MVC force was constantly loaded to each patient during the isometric exercise. There were no differences of intracellular pH (pHi) and inorganic phosphate/phosphocreatine(Pi/PCr) at baseline, exhaustion state and recovery period between two groups. But pHi during the exercise was lower in patients group than the control group (p < 0.05). Pi/PCr during the exercise did not show significant difference between two groups. These results suggest that the exercise limitation in chronic lung disease patients without hypoxia also could be attributed to the abnormalities in the skeletal muscle metabolism.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1234-1244
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• 1997

Background : Nowadays drug resistant tuberculosis is making problems in the treatment of pulmonary tuberculosis and its number is increasing. Several reasons for this are considered including irregular medication, poor drug compliance and wrong regimens. But there are treatment failure cases in spite of regular medication with short-term standard regimens. We reviewed clinical data of 50 patients to find out possible causes of this. Method : Subject of this study was 50 patients who failed in the primary treatment of pulmonary tuberculosis in spite of regular medication with short-term standard regimens. All of them were under treatment with secondary regimens in National Masan Tuberculosis Hospital on Oct 1996. The patient's records were analyzed retrospectively and direct interviews with patients were done. Results : There were relatively more patients in the age of 20th. Male overwhelmed in number. There were smoking in 22 patients and drinking in 24 patients during medication. 17(34%) patients had family history of tuberculosis. Public health center was the most common site for the initial diagnosis among medical institutes. 42 patients had subjective symptoms for pulmonary tuberculosis. 38 patients got sufficient explanation from medical institute about tuberculosis and medication courses. 24 patients had bilateral lesions on chest X-ray film and 43 patients had cavitary lesions. 29 patients had past history for pulmonary tuberculosis with regular medication. The results of drug sensitivity test showed resistance in 41 patients of whom we could get the results. Conclusion : Main cause of treatment failure of pulmonary tuberculosis in spite of regular medication with short-term standard regimens was drug resistance. Several factors were considered to be related to high prevalence of drug resistance, including age of 20th, male, family history for tuberculosis, bilateral lesions or remaining cavitary lesion on chest X-ray film.