• The Korean Journal of Nuclear Medicine
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• v.28 no.3
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• pp.307-312
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• 1994

Interictal single photon emission computed tomography of regional cerebral blood flow (rCBF SPECT) in 18 intractable temporal lobe epilepsy patients(8 male and 10 female patients: average 23.5 years old) were compared with 2.0 T magnetic resonance imaging (MRI). And surgical outcome was analysed with the findings, symptom duration and lateralization of temporal lobe. Preoperatively rCBF SPECT was done in all 18 patients with intravenous injection of 740 MBq 99mTc-HMPAO. MRI was also done preoperatively in 13 patients. Surgical outcome was classified by Engel's outcome classification(four-part classification recommended at the first Palm Desert conference). rCBF SPECT detected correctly lateralising abnormality of temporal lobe hypoperfusion in 13/18(72.2%), contralateral temporal lobe hypoperfusion in 2/18(11.1%) and showed no def-inite abnormality in 3/18(16.7%). The positive predictive value of unilateral temporal lobe hypoperfusion was 87%. MRI detected correct localising abnormality in 8/13(61.5%), such as hippocampal atrophy(7/13), asymmetric temporal horn(6/13), anterior temporal lobe atrophy(1/13), increased signal intensity from hippocampus(1/13) and calcific density(1/13), and no abnormal finding was noted in 5/13(38.5%). There was no false positive findings and the positive predictive value of MRI was 100%. Only 2 cases showed same lateralization findings in rCBF SPECT and MRI. There was no significant correlation between symptom duration and no abnormal findings on SPECT or MRI. Surgical outcome showed class I in 15/18(83.3%), and class II in 2/18(11.1%). One case of no abnormal finding in both SPECT and MRI showed class III surgical outcome. No class IV surgical outcome was noted. Surgical outcome, lateralization of epileptic focus in temporal lobe and abnormal findings in rCBR SPECT or MRI were not significantly correlated.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.443-450
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• 2009

Purpose: Conventional image reconstruction uses simplified physical models of projection. However, real physics, for example 3D reconstruction, takes too long time to process all the data in clinic and is unable in a common reconstruction machine because of the large memory for complex physical models. We suggest the realistic distributed memory model of fast-reconstruction using parallel processing on personal computers to enable large-scale technologies. Materials and Methods: The preliminary tests for the possibility on virtual manchines and various performance test on commercial super computer, Tachyon were performed. Expectation maximization algorithm with common 2D projection and realistic 3D line of response were tested. Since the process time was getting slower (max 6 times) after a certain iteration, optimization for compiler was performed to maximize the efficiency of parallelization. Results: Parallel processing of a program on multiple computers was available on Linux with MPICH and NFS. We verified that differences between parallel processed image and single processed image at the same iterations were under the significant digits of floating point number, about 6 bit. Double processors showed good efficiency (1.96 times) of parallel computing. Delay phenomenon was solved by vectorization method using SSE. Conclusion: Through the study, realistic parallel computing system in clinic was established to be able to reconstruct by plenty of memory using the realistic physical models which was impossible to simplify.

• Journal of Chest Surgery
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• v.53 no.2
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• pp.64-72
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• 2020

Background: It is generally agreed that using a bilateral internal thoracic artery (BITA) composite graft improves long-term survival after coronary artery bypass grafting (CABG). Although the left internal thoracic artery (LITA)-based Y-composite graft is widely adopted, technical or anatomical difficulties necessitate complex configurations. We aimed to investigate whether BITA configuration impacts survival or patency in patients undergoing coronary revascularization. Methods: Between January 2006 and June 2017, 1,161 patients underwent CABG at Seoul National University Bundang Hospital, where the standard technique is a LITA-based Y-composite graft with the right internal thoracic artery (RITA) sequentially anastomosed to non-left anterior descending (LAD) targets. Total of 160 patients underwent CABG using BITA with modifications. Their medical records and imaging data were reviewed retrospectively to investigate technical details, clinical outcomes, and graft patency. Results: Modifications of the typical Y-graft (group 1, n=90), LITA-based I-graft (group 2, n=39), and RITA-based composite graft (group 3, n=31) were used due to insufficient RITA length (47%), problems using LITA (28%), and target vessel anatomy (25%). The overall 30-day mortality rate was 1.9%. Among 116 patients who underwent computed tomography or conventional angiography at a mean interval of 29.9±33.1 months postoperatively, the graft patency rates were 98.7%, 95.3%, and 83.6% for the LAD, left circumflex artery, and right coronary artery territories, respectively. Patency rates for the inflow, secondary, and tertiary grafts were 98.2%, 90.5%, and 80.4%, respectively. The RITA-based graft (group 3) had the lowest patency rate of the various configurations (p<0.011). Conclusion: LITA-based Y composite graft, showed satisfactory clinical outcomes and patency whereas modifications of RITA- based composite graft had the lowest patency and 5-year survival rates. Therefore, when using RITA-based composite graft, other options should be considered before proceeding atypical configurations.

• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.135-140
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• 2013

We report a case of recurrent shoulder dislocation and combined proximal humerus fracture in neurofibromatosis type I. A twenty-year-old male patient with known neurofibromatosis type I presented with right shoulder dislocation and proximal humerus fracture following a minor trauma. His injured arm also had large plexiform neurofibromas on the elbow, and the dislocation of the shoulder joint was proven to be recurrent. Bony deformation of the humerus and scapula were revealed on X-ray and computed tomography, as well as multiple neurofibromatic changes of the deltoid and periscapular muscles were noted on magnetic resonance imaging. Open reduction and capsular reconstruction were performed and humeral fracture was stabilized with a reconstruction plate. Satisfactory union and functional result were achieved and the dislocation did not recur until the 7-month followup after the procedure. Recurrent shoulder dislocation and combined proximal humerus fracture in neurofibromatosis type I are rare complications. However, it should still be considered in the orthopaedic evaluation process of the diseases.

• Advances in pediatric surgery
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• v.11 no.2
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• pp.150-156
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• 2005

Failure of the urachus to regress completely results in anomalies that may be classified as patent urachus, urachal sinus, urachal cyst and bladder diverticula. The presenting symptoms of children with urachal anomalies are variable and uniform guidelines for diagnosis and treatment are lacking. The purpose of this study was to analyze our experience and develop conclusions regarding the presentation, diagnosis and treatment of urachal anomalies. We retrospectively analyzed the records of 32 patients who were admitted for urachal anomalies from March 1995 to February 2005. The age distribution of these patients at presentation ranged from 1 day to 14 years old (median age 1 month). There were 20 boys and 12 girls. The 32 cases comprised 13 cases of urachal sinus (40.6 %), 10 urachal cyst (31.3 %), and 9 patent urchus (28.1 %). In 30 patients ultrasonography was used for diagnosis and 2 patients with patent urachus were explored without using a diagnostic method. Twenty-three patients were confirmed by ultrasonography alone and 7 patients were examined using additional modalities, namely, computed tomography for 2 patients with an urachal cyst, magnetic resonance imaging for 1 patient with an urachal cyst, and fistulography for 3 patients with an urachal sinus. The presenting symptoms were umbilical discharge (14 patients), umbilical granuloma (8), abdominal pain and fever (3), fever (3), abdominal pain (2), and a low abdominal mass (2). Excision was performed in 29 patients, and 3 patients were conservatively managed. Urachal anomalies in children most frequently presented in neonates, and the most common complaint was umbilical discharge with infection. Urachal anomalies can be diagnosed by a physical examination and an appropriate radiographic test. Ultrasound was the most useful diagnostic method. Complete surgical excision of an urachal anomaly is recommended to avoid recurrence, and the rare development of carcinoma.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.1
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• pp.61-71
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• 2009

Anchorage control is important in orthodontic treatment. Recently miniscrew is widly used as maximum anchorage in orthodontic treatment, and then it is important to install miniscrew safely without damaging adjacent anatomic structure. In a view of Miniscrew's stability, maxilla is unfavorable than mandible, and moreover maxillary soft buccal bone has disadvantage on stability. so palatal area comes into notice for installation area. We measured distance between palatal roots and bone thickness at midpalatal area using 3D computed tomography, and have found following results. 1. On the comparison of distance between palatal roots, the distance between 2nd premolar and 1st molar was significantly longest and the distance between premolars was significantly shortest. 2. Going toward lateral area from midpalatal suture and posterior area from zero point, bone thickness significantly became shorter and shorter. And 5.0mm palatal sagittal plane has more significance decrease of bone thickness than 2.5mm palatal sagittal plane. According to these results, we can conclude that the palatal installation of miniscrew between 2nd premolar and 1st molar is safest. And it is more safe that comes closer to midpalatal suture and to anterior area in regard to incisive canal.

• The Journal of the Korean bone and joint tumor society
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• v.8 no.3
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• pp.83-89
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• 2002

Purpose: To analyze the postoperative functional and radiographic follow-up results in patients who underwent percutaneous radiofrequency ablation therapy after the diagnosis of osteoid osteoma. Materials and Methods: Seven patients, who were clinically and radiographically diagnosed with osteoid osteoma from July 1999 to January 2001, and received percutaneous radiofrequency ablation therapy. The average follow-up period was 15.5 months(range, 8~25 months). For the diagnosis and accurate localization of the lesion, simple radiography, computed tomography and magnetic resonance imaging(MRI) were performed preoperatively. Simple radiographs and MRI were taken periodically for the follow-up studies. Results: In all 7 patients, symptoms completely disappeared within 3 days after the operation. The average period of hospitalization was 2.4 days, excluding 1 patient who needed an additional burn treatment. The average postoperative night and day pain scores were 1.8 and 1.3, respectively. The average vocational and recreational activity scores were 1 and 0.6, respectively. Conclusions: Satisfactory functional results were obtained with percutaneous radiofrequency ablation therapy for the elimination of osteoid osteoma. Compared to conventional treatment, the advantages of this therapy were short hospitalization period, no internal fixation and bone graft for preventing fracture, and no limitation of joint motion by long fixation period.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.224-230
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• 2010

Purpose: We designed the aft-multiple-slit (AMS) system to reduce scatter in cone-beam computed tomography (CBCT). As a preliminary study, we performed a Monte Carlo N-Particle Transport Code (MCNP) simulation to verify the effectiveness of this system. Materials and Methods: The MCNPX code was used to build the AMS geometry. An AMS is an equi-angled arc to consider beam divergence. The scatter-reduced projection images were compared with the primary images only and the primary plus scatter radiation images with and without AMS to evaluate the effectiveness of scatter reduction. To obtain the full 2 dimensional (2D) projection image, the whole AMS system was moved to obtain closed septa of the AMS after the first image acquisition. Results: The primary radiation with and without AMS is identical to all the slit widths, but the profiles of the primary plus scattered radiation varied according to the slit widths in the 2D projection image. The average scatter reduction factors were 29%, 15%, 9%, and 8% when the slit widths were 5 mm, 10 mm, 15 mm, and 20 mm, respectively. Conclusion: We have evaluated the scatter reduction effect of the AMS in CBCT imaging using the Monte Carlo (MC) simulations. A preliminary study based on the MCNP simulations showed a mount of scatter reduction with the proposed system.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.221-225
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• 2000

Purpose : This study was designed to examine the reliability of the new version of the AJCC staging system (1997) of nasopharyngeal carcinoma in comparison with the AJCC staging system of 1992. Materials and Methods :Between 1983 and 1996, 185 patients with histologically proven nasopnaryngeal carcinoma were treated with radiation therapy at the Department of Therapeutic Radiology Seoul National University Hospital. For these patients, AJCC staging system of 1992 was compared with the 1997 version by reviewing hospital records, computed tomography (CT) and/or magnetic resonance imaging (MRI). Results :5-year overall suwival rates according to the 1992 and 1997 AJCC staging systems were 100$\%$, and 100$\%$ at stage 1: 100$\%$, and 68.8$\%$ at stage 11; 61.4$\%$, and 63.8$\%$ at stage 111; 61.1$\%$, and 63.2$\%$ at stage IV. S-year overall survival rates of each classification showed significant differences between stages (p=0.0049 for the old version, p=0.01 for the new), but no significant difference was found between the staging systems except at stage 11. Conclusion : The new AJCC staging system allows staging as reliably as the 1992 version, but the adequacy of the newly modified staging classification should be confirmed by further clinical examination.

• Journal of Acupuncture Research
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• v.17 no.3
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• pp.265-276
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• 2000

Objectives : The purpose of this study is to observe the clinical characteristics of 6 patients who were not improved after admitted conservative treatment in this 311 patients. Methods : We retrospectivety reviewed 311 patients of Herniated Lumbar Intervertebral Disc which undenvent admitted conservative treatment from November 1997 to June 2000. 311 patients were diagnosed by computed tomography or magnetic resonance imaging in addition to physical examination. Other complications were not detected in 311 patients with Hemiated Lumbar Intervertebral Disc. In case that the scoliosis appeared to caused by severe pain, we included this scoliosis patient with the object of survey. Results : 1. In 6 patients who were not improved, 4 patients were large herniation and 2 patients were medium herniation. 2. In all of 6 patients, the angle of straight leg raising test was low and was not imporved unril discharge. 3. X-ray findings showed straightening in all of 6 patients, disc space narrowing in 3 of 6 patients. 4. X-ray findings showed scoliosis in 3 of 4 patients who were severe pain. 5. The onset was relarively long from 30 days to 7 years. 6. The age was relatively young from 10's to 30's. 7. The adimission date was ralatively long from 32 days to 105 days. Conclusions : In 6 patients, there were observed much volume of disc herniation, low angle of straight leg raising test, young people in an age group, straightening of x-ray finding.