• Journal of Radiation Protection and Research
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• v.33 no.2
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• pp.47-51
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• 2008

Objective: This study analyzed errors due to rotation or tilt of the magnetic resonance (MR) imaging indicator during image acquisition for a stereotactic radiosurgery. The error correction procedure of a commercially available stereotactic neurosurgery treatment planning program has been verified. Materials and Methods: Software virtual phantoms were built with stereotactic images generated by a commercial programming language, Interactive Data Language (version 5.5). The thickness of an image slice was 0.5 mm, pixel size was $0.5{\times}0.5mm$, field of view was 256 mm, and image resolution was $512{\times}512$. The images were generated under the DICOM 3.0 standard in order to be used with Leksell GammaPlan$^{(R)}$. For the verification of the rotation error correction function of Leksell GammaPlan$^{(R)}$, 45 measurement points were arranged in five axial planes. On each axial plane, there were nine measurement points along a square of length 100 mm. The center of the square was located on the z-axis and a measurement point was on the z-axis, too. Five axial planes were placed at z=-50.0, -30.0, 0.0, 30.0, 50.0 mm, respectively. The virtual phantom was rotated by $3^{\circ}$ around one of x, y, and z-axis. It was also rotated by $3^{\circ}$ around two axes of x, y, and z-axis, and rotated by $3^{\circ}$ along all three axes. The errors in the position of rotated measurement points were measured with Leksell GammaPlan$^{(R)}$ and the correction function was verified. Results: The image registration errors of the virtual phantom images was $0.1{\pm}0.1mm$ and it was within the requirement of stereotactic images. The maximum theoretical errors in position of measurement points were 2.6 mm for a rotation around one axis, 3.7 mm for a rotation around two axes, and 4.5 mm for a rotation around three axes. The measured errors in position was $0.1{\pm}0.1mm$ for a rotation around single axis, $0.2{\pm}0.2mm$ for double and triple axes. These small errors verified that the rotation error correction function of Leksell GammaPlan$^{(R)}$ is working fine. Conclusion: A virtual phantom was built to verify software functions of stereotactic neurosurgery treatment planning program. The error correction function of a commercial treatment planning program worked within nominal error range. The virtual phantom of this study can be applied in many other fields to verify various functions of treatment planning programs.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.111-119
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• 1999

Purpose: As mesial temporal lobe epilepsy (TLE) shows hypometabolism of medial and lateral temporal lobe, we investigated whether symmetric uptake of F-18-FDG in medial temporal lobes can differentiate mesial from lateral TLE. Materials and Methods: In 113 patients (83 mesial TLE, 30 lateral TLE) who underwent anterior temporal lobectomy and/or corticectomy with good surgical outcome, we performed F-18-FDG PET and compared F-18-FDG uptake of medial and lateral temporal lobes. All the patients with mesial TLE had hippocampal sclerosis except one congenital abnormal hippocampus. Patients with lateral TLE revealed cerebromalacia, microdysgenesis, arteriovenous malformation, old contusion, and cortical dysplasia. Results: Sensitivity of F-18-FDG PET and MR for mesial TLE was 84% (70/83) and 73% (61/83), respectively. Sensitivity of F-18-FDG PET and MR for lateral TLE was 90% (27/30) and 66% (20/30), respectively. Twelve patients were normal on F-18-FDG PET. 101 patients had hypometabotism of lateral temporal lobe. Among 88 patients who showed hypometabolism of medial temporal lobe as well as lateral temporal lobe, 70 were mesial TLE patients and 18 were lateral TLE on pathologic examination. Positive predictive value of medial temporal hypometabolism for mesial TLE was 80%. Among 13 patients who showed hypometabolism of only lateral temporal lobe, 4 were mesial TLE and 9 were lateral TLE. Positive predictive value of hypometabolism of lateral temporal lobe for the diagnosis of lateral TLE was 69% (9/13). Normal MR findings stood against medial TLE, whose negative predictive value was 66%. Conclusion: Lateral temporal lobe epilepsy should be suspected when there is decreased F-18-FDG uptake in lateral temporal lobe with normal uptake in medial temporal lobe.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.180-188
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• 2009

Purpose: We evaluate the short-term clinical outcome of arthroscopic rotator cuff tendon repair with suture-bridge technique in patients with full thickness rotator cuff tear. Materials and Methods: 29 (male:17, female:12) consecutive shoulders treated with this index procedure and early rehabilitation were enrolled. Mean age was 56.4 years (range, 34~73 years) and mean follow-up period was 13 months (range, 12-15 months). Clinical outcomes were evaluated by using the University of California Los Angeles (UCLA) score, the Korean Shoulder Scoring System (KSS) and Visual Analogue Scale (VAS). Postoperative cuff integrity was evaluated through magnetic resonance imaging (MRI) and categorized by Sugaya classification. Results: Postoperative UCLA scores improved from 16.4 to 31.6 (p< 0.05) and KSS scores showed 88 at 6 months and 92 at last follow up. Preoperative VAS score was 8.6, which was decreased to 2.1 at 3 months and 1.4 at 6 months postoperatively. 28 patients (96.5%) had increase in range of motion. The follow up MRI was taken in 15 shoulders and the cuff integrity was type I in 6 cases, type II in 7, type III in 1 and type V in 1 by Sugaya classification. Conclusion: Arthroscopic suture-bridge technique resulted in good or excellent clinical outcome in 96.5% of the cases, so we think this technique is one of the reliable procedure for full-thicknes rotator cuff tear.

• Journal of radiological science and technology
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• v.28 no.3
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• pp.219-226
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• 2005

By analyzing the severally clinical characteristics such as the prevalence by gender and age, and the developmental region, and the developmental factor in terms of vertebral compression fracture, which was diagnosed by MRI(Magnetic Resonance Imaging), the following conclusions were obtained. 1. The general characteristics in 183 research subjects, were 70 men (38.0%) and 113 women (62.0%), and aged from the minimum 16 years old to the maximum 84 years old. 2. Among 183 persons with abnormal findings in vertebral compression fracture, the single compression fracture was included 111 persons (60.7%) with 38 men (34.0%) and 73 women (66.0%), and women in their 60s were largest with 32 persons. 3. As the multiple compression fracture was included 72 persons (39.3%) among 183 research subjects, and as the incidence had 182 cases, this is what classified the case in which one person with abnormal findings has the compression fracture at the levels with more than one, and there were 70 cases (38.0%) in men and 112 cases (62.0%) in women, and it is being indicated the large frequency in women in their 60s and in their 70s. 4. The developmental regions in the single compression fracture and the multiple compression fracture, were generated about 70% of the whole at $T11{\sim}L2$. 5. In terms of the prevalence by cause for compression fracture in 183 whole subjects, it was largest with 41.4% in the fracture caused by trauma in case of men, and with 70.0% in what was caused by the osteoporosis in case of women, and as for a case that combined men and women, it was largest with 56.8% in the vertebral compression fracture caused by osteoporosis.

• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.154-163
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• 2015

Purpose: Osteoarticular infections in children and adolescents are important because it can cause functional compromise if appropriate treatment is delayed. Therefore, this study was designed to describe the clinical presentations and causative organisms of osteoarticular infections in children and adolescents in order to propose early diagnosis method and an appropriate empiric antimicrobial therapy. Methods: Forty-two medical records were reviewed retrospectively, which were confirmed as osteomyelitis (OM) or septic arthritis (SA) at Department of Pediatrics or Orthopedic Surgery in patients under 18 years old of Ewha Womans University Mokdong Hospital from March 2008 to March 2015. Results: We identified 21 cases of OM, 13 cases of SA and 8 cases of OM with SA. There were 31 males and 11 females and mean age was 7.1 years old. The most common symptoms were pain and tenderness of involved site. Major involved bones were femur (10 cases, 34.5%), tibia (7 cases, 24.1%) and major involved joints were hip (9 cases, 42.9%), and knee (5 cases, 23.8%). Increased serum C-reactive protein and erythrocyte sedimentation rate were observed in 37 cases (88.1%) respectively. Magnetic resonance imaging was performed in 40 cases among 42 cases and was used to demonstrate osteoarticular infections and other adjacent infections. Nine cases (23.7%) among 38 cases and 20 cases (50.0%) among 40 cases were positive in blood culture and infected site culture respectively. The most common causative organism was Staphylococcus aureus, which was represented in 22 cases (75.9%), of which nine cases (40.9%) were resistant to methicillin. Conclusions: S. aureus was the most common causative organism of osteoarticular infections in children and adolescents and the proportion of MRSA was high in this study. Therefore, we recommend vancomycin as the first empiric antimicrobial therapy and suggest that further study is necessary to elucidate an appropriate guideline for treatment which takes into account MRSA proportion.

• Journal of Genetic Medicine
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• v.4 no.1
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• pp.38-44
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• 2007

Purpose : Menkes disease is an X-linked recessively inherited disorder caused by the mutation of the ATP7A gene encoding copper-transporting P-type AT Pase. The phenotypic features are progressive neurological degeneration, mental retardation, loose skin, and vascular complications. Early diagnosis and treatment are very important for the prognosis of Menkes disease. Here, we describe nov el mutations of the ATP7A gene and prenatal diagnosis by mutation analysis. Methods : Five unrelated Korean Menkes patients were included in this study. They presented with depigmented wool-like hair, progressive neurologic deterioration, and hypotonia in infancy. Serum copper and ceruloplasmin levels w ere decreased. Brain magnetic resonance imaging revealed tortuous intracranial vessels. Mutation analysis has been carried out using cDNA from cultured skin fibroblasts or genomic DNA from peripheral leukocytes. Prenatal diagnosis was performed in two cases using chorionic villi samples or amniocytes. Results : Four novel mutations have been identified from four different families; c.3511+1G>A (p.E1099_N1171delinsMfsX 18), c.4005+5 G>A (p.V1268_R1335del), c.1870_2172del (p.S624_Q724del), and c.3352 G>A (p.G1118S). T he remaining one was previously reported (c.1933 C>T (p.V 1268_R1335del)). On prenatal DNA analysis, one w as diagnosed as normal, while the other turned out to be a female heterozygote with p.S624_Q724del mutation of the ATP7A gene. Conclusion : We identified 4 novel mutations of the ATP7A gene. Prenatal diagnosis in families at risk is critical in order to choose preventiv e options including an early treatment with copper-histidine therapy or therapeutic termination. Most mutations of the ATP7A gene were frame-shift mutations and prenatal diagnosis has been successfully carried out.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.178-186
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• 2009

The quality control is needed to ensure the accuracy of medical information and achieved by evaluating the performance of and maintaining the system and practicing various measurements and evaluations. The Korean Institute for Accreditation of Medical Image, therefore, have held educational program for quality control of special medical equipments. The major of programs participants, however, are radiology specialists with only small number of radiological technologists from some hospitals, furthermore, the follow-up education and the share of information between participants and non-participants are insufficient in general, thus, the knowledge level of radiological technologists, regardless of their participation, is relatively low. This study carried out the questionnaire research for the 500 radiological technologists registered in Korean Society of MRI Technology, on the basis of 2008, and performed analysis for five months from May to Oct., 2008. The questionnaires were delivered by post to each radiological technologists and the response rate was 36%(n=180). The results of this revealed that the 86.7% of respondents felt the necessity of inspection on quality management, while only the 27.8% completed the educational program for manager of special medical equipment. and only the half(53.9%) had the knowledge about inspection on quality management. The completion of educational program had no correlations with sex, age, size of occupying hospital, the number of radiological technologists in occupying site and MRI laboratory, career year of general radiologist and in MRI laboratory, and the presence of biomedical engineering department in occupying hospital. The 78.0% of participants at the educational program for quality management held by the Korean Institute for Accreditation of Medical Image had the knowledge about inspection on quality management(p<.05) whereas the 43.9% of the hospitals held such program and the 54.4% of radiological technologists from those hospitals had related knowledge, which indicated that such programs held by hospitals had not effects on the knowledge level of radiological technologists. This indicates also that the contents, methods, and other conditional factors of educational programs are important for the outcome of them.

• Journal of the Korean Child Neurology Society
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• v.26 no.4
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• pp.197-204
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• 2018

Purpose: West syndrome is a severe form of age-specific epilepsy that typically affects infants younger than 2 years of age with mitochondrial disease. We aimed to examine age-specific characteristics of the syndrome in these patients. Methods: We retrospectively analyzed 54 patients with West syndrome diagnosed with mitochondrial disease between March 2006 and March 2016. We compared treatment strategies and diagnostic and clinical variables between patients with early-onset (<6 months of age) and late-onset (${\geq}6$ months of age) seizures. Results: Seizure was the first symptom in 30 (90.9%) and 13 (65%) patients of the early-onset and late-onset groups, respectively (P=0.046). Delayed development was observed in 3 (9.1%) and 7 (35%) patients of the early-onset and late-onset groups, respectively (P=0.023). Lactate levels were normal in 17 patients (55%) of the early-onset group and 5 (25%) of the late-onset group (P=0.036), while initial brain magnetic resonance imaging (MRI) findings were normal in 23 (67.6%) and 8 (40%) patients of the early-onset and late-onset groups, respectively. Final MRI findings were abnormal in 32 patients (94.1%) of the early-onset group and 18 (90%) of the late-onset group (P=0.036). Although ketogenic diets reduced seizure frequency in both groups, the difference was not significant. Conclusion: There is no significant difference in epilepsy-related variables when patients are divided based on a cut-off age of 6 months. However, differences in the first symptom at onset and MRI findings were observed. Although lactate levels were not of significant diagnostic value in the early-onset group, they may be in the late-onset group.

• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.160-168
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• 2018

Study Design: Retrospective study of prospectively-collected data. Objectives: To determine the factors associated with conversion from conservative to surgical treatment in single-level lumbar spinal stenosis patients. Summary of Literature Review: Various reports have presented clinical outcomes after the surgical and nonsurgical treatment of spinal stenosis. However, few reports have investigated factors predicting conversion to surgery during the course of conservative treatment. Materials and Methods: We analyzed 40 patients who visited our hospital from May 2010 to May 2015 and were traceable for at least 3 years after being advised to undergo surgery following 3 months of conservative treatment. Of these patients, 20 underwent surgery and 20 did not. We then investigated the factors associated with conversion to surgical treatment. Clinical assessments were conducted using a questionnaire, and the overall area of the spinal canal and the muscle area within the spinal canal were measured using magnetic resonance imaging. Results: The average area of the spinal canal was $81.40{\pm}53.61mm^2$ in the surgical group, compared to $127.75{\pm}82.55mm^2$ in the nonsurgical group (p=0.042). The muscle area in the spinal canal was $5.17{\pm}1.30cm^2$ in the surgical group, whereas it was $6.40{\pm}1.56cm^2$ in the nonsurgical group (p=0.010). The patients in the surgical group were more likely to have experienced repetitive strain and to have frequently visited health clubs (p=0.047, p=0.037, respectively). However, regular stretching was more common in the nonsurgical group (p=0.028). Conclusions: The factors associated with conversion to surgical treatment were a narrow spinal canal, a small muscle area within the spinal canal, visiting health clubs, repetitive sprain, and not stretching. A small muscle area within the spinal canal can be considered as a key factor related to surgical conversion.

• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.147-153
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• 2018

Study Design: Retrospective case series. Objectives: We retrospectively evaluated the clinical efficacy of postganglionic nerve block in symptomatic Schmorl nodules (SNs). Summary of Literature Review: SNs are common lesions that are often asymptomatic. In certain cases, SNs have been reported to cause severe axial back pain, thereby considerably impacting patients' quality of life. No consensus currently exists on the treatment of symptomatic SNs. Materials and Methods: From October 2015 to October 2017, a total of 21 patients with symptomatic SNs diagnosed by magnetic resonance imaging (MRI) that did not respond to conservative treatment after 4 weeks were included in the study. All patients received postganglionic nerve block. We evaluated effective pain relief (improvement of back pain of more than 50% compared with before the intervention) and functional improvements, assessed by visual analogue scale (VAS) and Oswestry Disability Index scores obtained at 4 hours, 4 weeks, 8 weeks, 3 months, and 6 months after the procedure. Results: Symptomatic SNs were more common at the L2-3 level, and the lower end plate was more commonly involved than the upper end plate. Eighteen of the 21 patients (85.7%) showed effective pain relief, and no deterioration was observed within the followup period. Throughout the follow-up period, the VAS remained significantly improved compared to before the procedure (p<0.05). Complications were not reported in any cases. Conclusions: Postganglionic nerve block for symptomatic SNs that do not respond to conservative treatment is a non-invasive modality for pain relief.