• Progress in Medical Physics
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• v.23 no.4
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• pp.292-302
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• 2012

The patient dose in advanced radiotherapy techniques is an important issue. These methods should be evaluated to reduce the dose in diagnostic imaging for radiotherapy. Especially, the Computed Tomography in radiotherapy has been used widely; hence the CT was evaluated for dose and image in this study. The evaluations for dose and image were done in equal condition due to compare the dose and image simultaneously. Furthermore, the possibility of dose and image evaluations by using the Monte Carlo simulation MCNPX was confirmed. We made the iterative reconstruction for low dose CT image to elevate image quality with Maximum Likelihood Expectation Maximization; MLEM. The system we developed is expected to be used not only to reduce the patient dose in radiotherapy, also to evaluate the overall factors of image modalities in industrial research.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.23.1-23.8
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• 2017

Background: The aim of this study is to validate a new three-dimensional craniofacial stereophotogrammetry imaging system (3dMDface) through comparison with manual facial surface anthropometry. The null hypothesis was that there is no difference between craniofacial measurements using anthropometry vs. the 3dMDface system. Methods: Facial images using the new 3dMDface system were taken from six randomly selected subjects, sitting in natural head position, on six separate occasions each 1 week apart, repeated twice at each sitting. Exclusion criteria were excess facial hair, facial piercings and undergoing current dentofacial treatment. 3dMDvultus software allowed facial landmarks to be marked and measurements recorded. The same measurements were taken using manual anthropometry, using soluble eyeliner to pinpoint landmarks, and sliding and spreading callipers and measuring tape to measure distances. The setting for the investigation was a dental teaching hospital and regional (secondary and tertiary care) cleft centre. The main outcome measure was comparison of the craniofacial measurements using the two aforementioned techniques. Results: The results showed good agreement between craniofacial measurements using the 3dMDface system compared with manual anthropometry. For all measurements, except chin height and labial fissure width, there was a greater variability with the manual method compared to 3D assessment. Overall, there was a significantly greater variability in manual compared with 3D assessments (p < 0.02). Conclusions: The 3dMDface system is validated for craniofacial measurements.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.1
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• pp.46-51
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• 2004

his paper presents a novel design technique for the TS fuzzy classifier via linear matrix inequalities(LMI). To design the TS fuzzy classifier built by the TS fuzzy model, the consequent parameters are determined to maximize the classifier's performance. Differ from the conventional fuzzy classifier design techniques, convex optimization technique is used to resolve the determination problem. Consequent parameter identification problems are first reformulated to the convex optimization problem. The convex optimization problem is then efficiently solved by converting linear matrix inequality problems. The TS fuzzy classifier has the optimal consequent parameter via the proposed design procedure in sense of the minimum classification error. Simulations are given to evaluate the proposed fuzzy classifier; Iris data classification and Wisconsin Breast Cancer Database data classification. Finally, simulation results show the utility of the integrated linear matrix inequalities approach to design of the TS fuzzy classifier.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3302-3309
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• 2011

This study showed the reduced greenhouse gas(GHG) emission through GHG inventory establishment and process diagnosis for a response to climatic change. Also, it presented a direction for company's response to climatic change. Ulsan from its industrial complex has many energy-intensive companies such as petrochemistry, automobile and shipbuilding, and as we judged that the systematic reduction of GHG emission would make a considerable reduction of GHG emission in national dimension we executed this study from 10 companies. It showed the high rate of direction GHG emissions by its process that 5 of 10 companies calculated GHG emission and built its inventory. Also, in order to reduce energy and GHG, it produced about 227,554 million won of its economic effect and 50,740 ton/yr of its sparing effect.

• Journal of Chest Surgery
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• v.47 no.3
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• pp.262-268
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• 2014

Background: The development of diagnostic techniques and an awareness of health examinations can bring about an early diagnosis of lung cancer. However, appropriate postoperative management and adjuvant chemotherapy remain under debate in postoperative therapeutic strategy. The present study was conducted to assess the clinicopathologic factors that influence recurrence and prognosis after complete resection of lung cancer. Methods: The present study analyzed 62 patients with lung cancer who underwent complete resection of diagnosed adenocarcinoma between 1994 and 2007. In addition to conventional factors, which include staging factor and histological evaluation, the present study also performed univariate and multivariate analyses to consider claudin, a cell adhesion molecule, as a prognostic factor by immunohistochemical staining. Results: There was no correlation between conventional factors, including lymphatic and vascular invasion, and recurrence. However, there was a significant correlation between high expression of claudin 4 and cancer recurrence. In particular, there was a correlation between high expressions of claudin 1, 4, and 5 and a reduction of disease-free survival. Conclusion: Increased expressions of claudin 4 were negative prognostic factors in adenocarcinoma of the lung and thus could be used to identify high-risk patients for adjuvant chemotherapy, even if they had early-stage lung cancer. The present findings collectively suggest that consideration of claudin as a prognostic factor in the active postoperative treatment in patients at high risk will lead to better therapeutic outcomes with fewer side effects.

• Journal of Trauma and Injury
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• v.21 no.2
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• pp.128-135
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• 2008

Purpose: As the care of surgical patients becomes increasingly complex and catheter-based techniques are more frequently applied, the pattern of iatrogenic vascular injuries may be increasing. Major vascular injuries can jeopardize a patient's life or limb survival. The purpose of this study was to examine the current etiology and prognosis for iatrogenic vascular injuries. Methods: We reviewed medical records of 29 cases of iatrogenic vascular injury that were treated Seoul National University Bundang Hospital between October 2003 and October 2008. We studied clinical variables including demographics, cause of injury, clinical presentations, management and prognosis. Results: The mean age was 60.8 years (range: 25-86), and the male to female ratio was 1.9 : 1. The causes of injuries were operation related complication in 18 cases (62.1%), endovascular intervention and diagnostic angiography in 11 cases (37.9%). The types of vascular injury were partial severance in 14 cases, pseudoaneurysm in 8, arteriovenous fistula (AVF) in 3, thrombosis in 2, complete severance in 2. Especially, device related complication including percutaneous closing device were occurred in 9 and the others came from inadvertent physician's procedure. Primary repair were done in 12 cases, end-to-end anastomosis in 5, interposition graft in 4, ligation in 2, patch angioplasty in 1, peudoaneurysm excision and arteriorrhaphy in 1, hematoma evacuation in 1, and endovascular repair in 3. There were 2 cases of mortality, one of them due to hemorrhagic shock and the other due to septic shock. Conclusion: Proper selection of treatment modalities should be important to have better outcome according to the type of injury as well as anatomical location. Each physician should be familiar to new device as well as patient's topographical feature. Immediate referral to vascular specialist is also essential to reduce morbidity.

• Journal of Biomedical Engineering Research
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• v.19 no.2
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• pp.171-176
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• 1998

The objective of this study was to re-evaluate ultrasound attenuation as an indicator of bone properties. Ultrasound attenuation(BUA), were measured in the three orthogonal directions of trabecular bone cubes, Measurements of bone mineral density(BMD) were made using quantitative computed tomography and apparent density by weighing bone specimens and measuring their volume. Ultrasonic modulus was calculated from the standard equation with apparent density and ultrasound velocity. Ultrasound attenuation at a frequency of 0.5 MHz and BUA were correlated with BMD and ultrasonic modulus in the anterior/posterior, medial/lateral, and superior/inferior directions. Analysis of correlations demonstrated that attenuation at 0.5 MHz was superior to BUA in describing both BMD and elastic modulus of trabecular bone. This result may be used to improve current ultrasound diagnostic techniques for assessing bone status.

• Journal of KIISE
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• v.42 no.7
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• pp.910-918
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• 2015

This paper presents a parameter visualization technique to overcome the limitation of the naked eye in contrast-enhanced ultrasonography. A method is also proposed to compensate for the distortion and noise in ultrasound image sequences. Meaningful parameters for diagnosing liver disease can be extracted from the dynamic patterns of the contrast enhancement in ultrasound images. The visualization technique can provide more accurate information by generating a parametric image from the dynamic data. Respiratory motions and noise from micro-bubble in ultrasound data may cause a degradation of the reliability of the diagnostic parameters. A multi-stage algorithm for respiratory motion tracking and an image enhancement technique based on the Markov Random Field are proposed. The usefulness of the proposed methods is empirically discussed through experiments by using a set of clinical data.

• Journal of Korean Neurosurgical Society
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• v.41 no.6
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• pp.371-376
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• 2007

Objective : The aim of this study was to investigate the usefulness of diffusion-weighted imaging [DWI] and apparent diffusion coefficiency [ADC] in distinguishing brain abscesses from cystic or necrotic brain tumors, which are difficult to be differentiated by conventional magnetic resonance imaging techniques. Methods : Seven patients with brain abscesses and ten patients with cystic brain tumors were studied from September 2003 to October 2005. Abscess, subdural empyema and ventriculitis were categorized to the abscess group and cystic or necrotic brain gliomas or metastatic brain tumors into the tumor group. Preoperative magnetic resonance images were performed in all patients and diffusion-weighted images and apparent diffusion coefficiency values of lesions were calculated directly from software of 1.5 tesla MRI [General Electrics, USA]. The ratio of the ADC of the lesion to contralateral regional ADC was also measured [relative ADC, rADC]. Results : The average ADC value of pyogenic abscesses group was $0.82+/-0.14{\times}10^{-3}\;[mean+/-S.D.]\;mm^2/s$ and mean rADC was 0.75. Cystic or necrotic areas had high ADC values [$2.49+/-0.79{\times}10^{-3}\;mm^2/s$, mean rADC=2.14]. ADC and rADC values of abscesses group showed about three times lower values than those of cystic or necrotic tumor group. Conclusion : This study results based on numerical comparison of signal intensities and quantitative analysis to distinguish between brain abscess and cystic or necrotic tumor, DWI and ADC mapping are thought to be very useful diagnostic tools.

• The Korean Journal of Urological Oncology
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• v.16 no.3
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• pp.89-96
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• 2018

Upper tract urothelial carcinoma (UTUC) has a relatively low prevalence rate of about 1.8 per 100,000 people. According to the recent literature, the development of diagnostic techniques has gradually increased the prevalence and diagnosis rate. In the past, when UTUC was diagnosed, more than 60% of the patients were diagnosed as locally advanced or metastatic cancer. However, since 2010, approximately 70% of the patients have been diagnosed as operable stage. Although radical nephroureterectomy is known as the basis of treatment for UTUC, overall survival is poor in patients with lymph node invasion. Especially, the finding that a localized UTUC is associated with a high risk of cancer metastasis in approximately 50% of patients suggests that these patients may not have sufficient treatment through surgery alone. The European Association of Urology and the National Comprehensive Cancer Network guideline 2017 suggested that postoperative adjuvant chemotherapy may be considered in patients with advanced UTUC beyond pT2. Also, recent meta-analyses have reported that cisplatin-based adjuvant chemotherapy can be expected to have a synergistic effect of overall survival and disease-free survival. However, many patients with UTUC undergo postoperative renal failure, which may result in failure to perform cisplatin-based adjuvant chemotherapy with adequate dose. For this reason, several researchers have suggested that it is beneficial to apply neoadjuvant chemotherapy when the preoperative renal function is maintained to a certain extent. But, neoadjuvant chemotherapy has not been used by many clinicians because of the lack of studies and the rarity of the disease. We are currently discussing the outcomes and prospects of perioperative chemotherapy.