• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.203-209
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• 2006

The aim of this study is to investigate the feasibility of ex vivo MR diffusion tensor imaging technique in order to observe the diffusion-contrast characteristics of human gastric tissues. On normal and pathologic gastric tissues, which have been fixed in a polycarbonate plastic tube filled with 10% formalin solution, laboratory made 3D diffusion tensor Turbo FLASH pulse sequence was used to obtain high resolution MR images with voxel size of $0.5{\times}0.5{\times}0.5mm^3\;using\;64{\times}32{\times}32mm^3$ field of view in conjunction with an acquisition matrix of $128{\times}64{\times}64$. Diffusion weighted- gradient pulses were employed with b values of 0 and $600s/mm^2$ in 6 orientations. The sequence was implemented on a clinical 3.0-T MRI scanner(Siemens, Erlangen, Germany) with a home-made quadrature-typed birdcage Tx/Rx rf coil for small specimen. Diffusion tensor values in each pixel were calculated using linear algebra and singular value decomposition(SVD) algorithm. Apparent diffusion coefficient(ADC) and fractional anisotropy(FA) map were also obtained from diffusion tensor data to compare pixel intensities between normal and abnormal gastric tissues. The processing software was developed by authors using Visual C++(Microsoft, WA, U.S.A.) and mathematical/statistical library of GNUwin32(Free Software Foundation). This study shows that 3D diffusion tensor Turbo FLASH sequence is useful to resolve fine micro-structures of gastric tissue and both ADC and FA values in normal gastric tissue are higher than those in abnormal tissue. Authors expect that this study also represents another possibility of gastric carcinoma detection by visualizing diffusion characteristics of proton spins in the gastric tissues.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.85-90
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• 2001

Objective : DREZotomy is effective for the treatment of deafferentation pain as a consequence of root avulsion, postparaplegic pain, posttraumatic syrinx, postherpetic neuralgia, spinal cord injury, and peripheral nerve injury. We performed microsurgical DREZotomy to the patients with deafferentation pain and relieved pain without any serious complication. The purpose of this study is to evaluate the usefulness of the microsurgical DREZotomy for deafferentation pain. Methods : We evaluated 4 patients with deafferntation pain who were intractable to medical therapy. Two of them were brachial plexus injury with root avulsion owing to trauma, one was axillary metastasis of the squamous cell carcinoma of the left forearm, and the last was anesthesia dolorosa after surgical treatment(MVD and rhizotomy) of trigeminal neuralgia. Preoperative evaluation was based on the neurologic examination, radiologic imaging, and electrophysiological study. In the case of anesthesia dolorosa, we produced two parallel lesions in cephalocaudal direction, 2mm in distance, from the C2 dorsal rootlet to the 5mm superior to the obex including nucleus caudalis, after suboccipital craniectomy and C1-2 laminectomy, with use of microelectrode. In the others, we confirmed lesion site with identification of the nerve root after hemilaminectomy. We performed arachnoid dissection along the posterolateral sulcus and made lesion with microsurgical knife and microelectrocoagulation, 2mm in depth, 2mm in distance, to the direction of 30-45 degrees in the medial portion of the Lissauer's tract and the most dorsal layers of the posterior horn at the one root level above and below the lesion. Results : Compared with preoperative state, microsurgical DREZotomy significantly diminished dosage of the drugs and relieved pain meaningfully. One patient showed tansient ipsilateral ataxia, but recovered soon. There was not any serious complication. Conclusion : It may be concluded that microsurgical DREZotomy is very useful and safe therapeutic modality for deafferentation pain, especially segmentally distributed intermittent or evoke pain. Complete preoperative evaluation and proper selection of the patients and lesion making device are needed to improve the result.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.120-123
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• 2001

Objectives : The present study was performed to analyze results of hydroxyurea treatment for unresectable and recurrent meningiomas as adjuvant chemotherapeutic agent. Material and Methods : Among 87 cases of meningioma patients who treated surgically between Jauary 1988 and December 1997 in our department, unresectable and recurrent cases were 4 cases. Histologically, 3 cases were meningothelial type, 1 case was angiomatous type. Tumor orgin was cerebellopontine angle(CPA) in 3 cases, cavernous sinus in 1 case. Three of 4 cases received radiation treatment. All patients received a daily dosage of 20mg/kg/day of hydroxyurea. Hematological monitorning was performed monthly and tumor measurement was assessed by MR imaging before treatment and every 6 months. Mean follow-up period was 34 months. Rerults : All cases showed no enlargement of tumor mass without any shrinkage. Trigeminal neuralgia in 1 case was improved and external herniation of brain on craniectomy site in 1 case was shrunken. None of the patients had any serious side effects. White blood cell count fell below $3000/{\mu}l$ in 1 case, but recovered 2 weeks later with cessation of medication. Conclusion : Hydroxyurea stopped cell growth by triggering the apoptotic cascade. Our preliminary data indicate that hydroxyurea provides adjuvant medical treatment in patients of unresectable and recurrent meningiomas

• Journal of Korean Neurosurgical Society
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• v.60 no.5
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• pp.577-583
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• 2017

Objective : Laminoplasty is an effective surgical method for treating cervical degenerative disease. However, postoperative complications such as kyphosis, restriction of neck motion, and instability are often reported. Despite sufficient preoperative lordosis, this procedure often aggravates the lordotic curve of the cervical spine and straightens cervical alignment. Hence, it is important to examine preoperative risk factors associated with postoperative kyphotic alignment changes. Our study aimed to investigate preoperative radiologic parameters associated with kyphotic deformity post laminoplasty. Methods : We retrospectively reviewed the medical records of 49 patients who underwent open door laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL) at Pusan National University Yangsan Hospital between January 2011 and December 2015. Inclusion criteria were as follows : 1) preoperative diagnosis of OPLL or CSM, 2) no previous history of cervical spinal surgery, cervical trauma, tumor, or infection, 3) minimum of one-year follow-up post laminoplasty with proper radiologic examinations performed in outpatient clinics, and 4) cases showing C7 and T1 vertebral body in the preoperative cervical sagittal plane. The radiologic parameters examined included C2-C7 Cobb angles, T1 slope, C2-C7 sagittal vertical axis (SVA), range of motion (ROM) from C2-C7, segmental instability, and T2 signal change observed on magnetic resonance imaging (MRI). Clinical factors examined included preoperative modified Japanese Orthopedic Association scores, disease classification, duration of symptoms, and the range of operation levels. Results : Mean preoperative sagittal alignment was $13.01^{\circ}$ lordotic; $6.94^{\circ}$ lordotic postoperatively. Percentage of postoperative kyphosis was 80%. Patients were subdivided into two groups according to postoperative Cobb angle change; a control group (n=22) and kyphotic group (n=27). The kyphotic group consisted of patients with more than $5^{\circ}$ kyphotic angle change postoperatively. There were no differences in age, sex, C2-C7 Cobb angle, T1 slope, C2-C7 SVA, ROM from C2-C7, segmental instability, or T2 signal change. Multiple regression analysis revealed T1 slope had a strong relationship with postoperative cervical kyphosis. Likewise, correlation analysis revealed there was a statistical significance between T1 slope and postoperative Cobb angle change (p=0.035), and that there was a statistically significant relationship between T1 slope and C2-C7 SVA (p=0.001). Patients with higher preoperative T1 slope demonstrated loss of lordotic curvature postoperatively. Conclusion : Laminoplasty has a high probability of aggravating sagittal balance of the cervical spine. T1 slope is a good predictor of postoperative kyphotic changes of the cervical spine. Similarly, T1 slope is strongly correlated with C2-C7 SVA.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.373-383
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• 2021

Our society is aging rapidly. In this super-aged society, the increase in healthcare costs are considered a national problem that undermines the sustainability of social security. Various services for healthcare for the elderly have been promoted to address this. However, most of them have focused on healthcare after the outbreak of chronic diseases and lack preventive healthcare. Most of the preventive healthcare projects are only pilots. In this paper, the current status of health care services for senior citizens at home and abroad was analyzed and based on this, the limitations and improvements were analyzed to propose the establishment of IoT-based Total Silver Care Center. IoT-based Total Silver Care Center may be conveniently monitored the health status of the elderly through various sensors, medical devices, and smart bands. And based on this, it can improve the quality of nursing services through time-saving and work efficiency of nursing providers. In addition, health care interventions may be provided in a timely manner if there is a change in the health status of users. And real-time imaging systems can help overcome mental difficulties.

• Annals of Surgical Treatment and Research
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• v.95 no.5
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• pp.286-296
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• 2018

Purpose: Sentinel lymph node (SLN) biopsy (SLNB) is widely accepted for staging of melanoma patients. It has been shown that clinico-pathological features such as Breslow thickness, ulceration, age, and sex are better predictors of relapse and survival than SLN status alone. The aims of this study were to evaluate the long-term (10-year) prognostic impact of SLNB and to determine predictive factors associated with SLN metastasis, relapse, and melanoma specific mortality (MSM). Methods: This was a prospective observational study on 289 consecutive patients with primary cutaneous melanoma who underwent SLNB from January 2000 to December 2007, and followed until January 2014, at an Italian academic hospital. Results: SLN was positive in 64 patients (22.1%). The median follow-up was 116 months (79-147 months). Tenyear disease-free survival and melanoma specific survival were poor in patients with positive SLN (58.7% and 66.4%, respectively). Only the increasing Breslow thickness resulted independently associated to an increased risk of SLN metastasis. Cox regression analysis showed that a Breslow thickness >2 mm was an independent predictor of relapse, and male sex and Breslow thickness >2 mm was a predictor of MSM. At 10 years, SLN metastasis was not significantly associated to either relapse or MSM. Conclusion: After the fifth year of follow-up, SLN metastasis is not an independent predictive factor of relapse or mortality which are mainly influenced by the characteristics of the primary tumor and of the patient. Patients with a Breslow thickness >2 mm regardless of the SLN status should be considered at high risk for 10-year relapse and mortality.

• Pediatric Infection and Vaccine
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• v.25 no.3
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• pp.113-122
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• 2018

Purpose: The aim of this study was to evaluate the clinical characteristics of children diagnosed as cryopyrin-associated periodic syndrome (CAPS) in Korea. Methods: Diagnosis was made based on clinical features and confirmed by a mutation in the cold-induced autoinflammatory syndrome 1 (CIAS1) gene. Especially, osteocartilaginous overgrowth in the patella or distal femur was so characteristic that its presence warranted a diagnosis of chronic infantile neurologic cutaneous and articular/NOMID. Results: We observed the clinical features of 9 Korean CAPS patients. All the patients suffered from an urticarial rash with recurrent fever. Among the 9 patients, 6 presented with rash and 4 with fever on the 1st or 2nd days of birth. Eight patients showed myalgia, and 7 patients showed arthralgia in the joints, and 6 patients showed radiologic findings of arthropathy including cupping of the metaphysis, excessive growth of the epiphysis, osteopenia or overgrowth of the cartilage. Four patients showed brain atrophy, enlarged ventricles or leptomeningeal enhancement on magnetic resonance imaging. Intellectual disability was observed in 1 patient. Five patients had eye involvement as conjunctivitis, uveitis, chorioretinitis, avascular area or papillary edema, and 3 patients showed progressive hearing loss. All 9 patients showed increased C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Conclusions: All the patients carried a mutation on exon 3 of the CIAS1 gene. After the anakinra (interleukin-1 receptor antagonist) therapy, the fever and rash immediately disappeared, and CRP and ESR were improved.

• Sleep Medicine and Psychophysiology
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• v.25 no.2
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• pp.82-91
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• 2018

Objectives: Synchronous electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) has been used to explore sleep stage dependent functional brain networks. Despite a growing number of sleep studies using EEG-fMRI, few studies have conducted network analysis on whole night sleep due to difficulty in data acquisition, artifacts, and sleep management within the MRI scanner. Methods: In order to perform network analysis for whole night sleep, we proposed experimental procedures and data processing techniques for EEG-fMRI. We acquired 6-7 hours of EEG-fMRI data per participant and conducted signal processing to reduce artifacts in both EEG and fMRI. We then generated a functional brain atlas with 68 brain regions using independent component analysis of sleep fMRI data. Using this functional atlas, we constructed sleep level dependent functional brain networks. Results: When we evaluated functional connectivity distribution, sleep showed significantly reduced functional connectivity for the whole brain compared to that during wakefulness. REM sleep showed statistically different connectivity patterns compared to non-REM sleep in sleep-related subcortical brain circuits. Conclusion: This study suggests the feasibility of exploring functional brain networks using sleep EEG-fMRI for whole night sleep via appropriate experimental procedures and signal processing techniques for fMRI and EEG.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.325-332
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• 2018

Carotid angiography covering the aortic arch includes contrast-enhanced magnetic resonance angiography (CEA), which is applied to a large region and usually employs contrast media. However, the use of contrast media can be dangerous in infants, pregnant women, and patients with chronic renal failure (CRF). Follow-up patients informed of a lesion may also want to avoid constant exposure to contrast media. We aimed to apply time-of-flight (TOF) angiography to a large region and compare its usefulness with that of CEA. Ten patients (mean age, 58 years; range, 45~75 years) who visited our hospital for magnetic resonance angiography (MRA) participated in this study. A 3.0 Tesla Achieva magnetic resonance imaging (MRI) system (Philips, Netherland) and the SENSE NeuroVascular 16-channel coil were employed for both methods. Both methods were applied simultaneously to the same patient. Three TOF stacks were connected to cover the aortic arch through the circle of Willis, and CEA was applied in the same manner. For the quantitative assessment, the acquired images were used to set the regions of interest (ROIs) in the common carotid artery (CCA) bifurcation, internal carotid artery, external carotid artery, middle cerebral artery, and vertebral artery, and to obtain the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) for the soft tissues. Three radiologists and one radiological resident performed the qualitative assessment on a 5-point scale - 1 point, "very bad"; 2 points, "bad"; 3 points, "average"; 4 points, "good"; and 5 points, "very good" - with regard to 4 items: (1) sharpness, (2) distortion, (3) vein contamination, and (4) expression of peripheral vessels. For the quantitative assessment, we estimated the mean SNR and CNR in each of the 5 ROIs. In general, the mean SNR was higher in TOF angiography (166.1, 205.2, 154.39, 172.23, and 161.95) than in CEA(92.05, 95.43, 84.76, 73.69, and 88.3). Both methods had a similar mean CNR: 67.62, 106.71, 55.9, 73.74, and 63.46 for TOF angiography, and 67.82, 71.19, 60.52, 49.45, and 64.07 for CEA. In all ROIs, the mean SNR was statistically significant (p<0.05), whereas the mean CNR was insignificant (p>0.05). The mean values of TOF angiography and CEA for each item in the qualitative assessment were 4.2 and 4.28, respectively for item 1; 2.93 and 4.55, respectively, for item 2; 4.6 and 3.13, respectively, for item 3; and 2.88 and 4.65, respectively, for item 4. Therefore, TOF angiography had a higher mean for item 3, and CEA had a higher mean for items 2 and 4; there was no significant difference between the two methods for item 1. The results for item 1 were statistically insignificant (p>0.05), whereas the results for items 2~4 were statistically significant (p<0.05). Both methods have advantages and disadvantages and they complement each other. However, CEA is usually applied to a large region covering the aortic arch. Time-of-flight angiography may be useful for people such as infants, pregnant women, CRF patients, and followup patients for whom the use of contrast media can be dangerous or unnecessary, depending on the circumstance.

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.713-718
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• 2018

In many previous studies, monte carlo simulation is used to produce lead-free shielding sheet, and the possibility of radiation shielding capability and weight reduction is presented. But it is difficult to simulation for binder and micro-pores because of In fact it does not provide sufficient information necessary for the commercialization process. Therefore, in this paper, the results of radiation shielding capability corresponding to filling factor was presented by using the screen printing method to provide information on gel-paste required for the commercialization process. In this study, the geometric setup for evaluate of radiation shielding ability was designed to comply with IEC 61331-1:2014 and KS A 4025. In addition, radiation irradiation conditions were 100 kVp filtered with 2.0 mmAl total filtration was applied according to KS A 4021 standard. In this study, Pb $1270{\mu}m$, $BaSO_4$ $3035{\mu}m$, $Bi_2O_3$ $1849{\mu}m$ and $WO_3$ $2631{\mu}m$ were analyzed based on ten value layer. Additionally, the filling factor was analyzed as $BaSO_4$ 38.6%, $Bi_2O_3$ 27.1%, $WO_3$ 30.15%. However, in the case of applying low-temperature high-pressure molding in the future, it is expected that the radiation shielding capability can be sufficiently improved by reducing the porosity while increasing the filling factor.