• 대한영상의학회지
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• 제84권5호
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• pp.1080-1090
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• 2023

목적 이 연구의 목적은 한국 인구에서 NeuroQuant (이하 NQ)와 DeepBrain (이하 DB)에서 측정된 뇌 용적과 정상규준 백분위수를 비교하고, 두개골 형태와의 연관성을 확인하는 것이다. 대상과 방법 이 연구는 구조적 뇌 이상이 없는 163명의 한국인을 대상으로 NQ와 DB에서 측정된 뇌 용적과 정상규준 백분위수를 비교하고, 두개골 형태와의 연관성을 확인한 후향적 연구이다. 급내상관계수분석과 선형분석의 통계학적 분석을 시행하였다. 결과 정상규준 백분위수는 시상(90.8 vs. 63.3 percentile), 피각(90.0 vs. 60.0 percentile), 그리고 두정엽(80.1 vs. 74.1 percentile)에서 NQ가 DB보다 더 큰 것으로 나타났고, 후두엽(18.4 vs. 68.5 percentile)은 DB가 NQ보다 큰 것으로 나타났으며, 특히 후두엽의 경우 두개골 형태와의 비교 연구에서 유의미한 연관성을 보였고, 두개골의 전후 방향의 길이와 비례하고 상하방향의 길이와는 반비례했다. 결론 NQ와 DB에서 얻은 정상규준 백분위는 각 뇌 영역마다 유의미한 차이를 보였고, 그 차이는 한국 인구의 두개골 형태와 유의미한 관계가 있었다.

• Journal of information and communication convergence engineering
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• 제8권2호
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• pp.205-211
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• 2010

In this study, a Magnetic stimulation Pulse Train control technique is introduced and applied to Flyback converter operating in discontinuous conduction mode. In contrast to the conventional pulse width modulation control scheme, the principal idea of a Magnetic stimulation Pulse Train is to achieve output voltage regulation using high and low power pulses. The proposed technique is applicable to any converter operating in discontinuous conduction. However, this work mainly focuses on Flyback topology. In this paper, the main mathematical concept of the new control algorithm is introduced and simulations as well as experimental results are presented.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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• pp.155-161
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• 2001

Anisotropic DWI - Mapping of the Proton Diffusion "tensor". In neural ordered tissue, it is thought that water diffusion is mainly influenced by the presence of myelin sheaths and intracellular structures. Perpendicular to the fiber tracts, the cholesterol-laden myelin lipid bilayers might restrict or hinder the spins from diffusing through the normally highly permeable cytomembrane. Diffusion along the fiber is more or less determined by subcellular structures, such as the endoplasmatic reticulum, mitochondria, neuro-filaments and macromolecules. In addition to that, the entire complex of axons and stabilizing tissue (i.e., glia cells, astrocytes) is also assumed to influence diffusion due to the tortuosity of proton translation, but the uniform distribution of such cells throughout the brain might render this notion less important as initially anticipated.

• Journal of Korean Neurosurgical Society
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• 제51권1호
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• pp.62-65
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• 2012

Despite the remarkable developments in neurosurgical and neuro-interventional procedures, the optimal treatment for large or giant partially thrombosed aneurysms with a mass effect remains controversial. The authors report a case of a partially thrombosed aneurysm with a mass effect, which was successfully treated by stent-assisted coil embolization. A 41-year-old man presented with headache. Brain computed tomography depicted an $18{\times}18$ mm sized thrombosed aneurysm in the interpeducular cistern. More than 80% of the aneurysm volume was filled with thrombus and the canalized portion beyond its neck measured $6.8{\times}5.6$ mm by diagnostic cerebral angiography. Stent-assisted endovascular coiling was performed on the canalized sac and the aneurysm was completely obliterated. Furthermore, most of the thrombosed aneurysm disappeared in the interpeduncular cistern was clearly visualized follow-up brain magnetic resonance imaging conducted at 21 months. The authors report a case of selective coiling of a large, partially thrombosed basilar tip aneurysm.

• 대한수의학회지
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• 제59권2호
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• pp.113-117
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• 2019

A 6-year-old intact male Maltese dog presented with a history of blindness and ataxia. Neuro-ophthalmic examination revealed dilated pupils with absent pupillary light reflexes and menace response in both eyes. Mild peripapillary edema was noted in the fundus of the right eye. After magnetic resonance imaging, the dog was provisionally diagnosed with meningoencephalitis of unknown etiology. Follow-up funduscopy was performed to monitor the condition of the optic discs for three years. Despite of the treatment with prednisolone, the optic nerve progressed to atrophy and the dog couldn't restore vision.

• Journal of Korean Neurosurgical Society
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• 제59권4호
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• pp.346-351
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• 2016

Objective : Early progressive infarction (EPI) is frequently observed and related to poor functional outcome in patients with middle cerebral artery (MCA) infarction caused by MCA occlusion. We evaluated the perfusion parameters of magnetic resonance imaging (MRI) as a predictor of EPI. Methods : We retrospectively analyzed patients with acute MCA territory infarction caused by MCA occlusion. EPI was defined as a National Institutes of Health Stroke Scale increment ${\geq}2$ points during 24 hours despite receiving standard treatment. Regional parameter ratios, such as cerebral blood flow and volume (rCBV) ratio (ipsilateral value/contralateral value) on perfusion MRI were analyzed to investigate the association with EPI. Results : Sixty-four patients were enrolled in total. EPI was present in 18 (28%) subjects and all EPI occurred within 3 days after hospitalization. Diabetes mellitus, rCBV ratio and regional time to peak (rTTP) ratio showed statically significant differences in both groups. Multi-variate analysis indicated that history of diabetes mellitus [odds ratio (OR), 6.13; 95% confidence interval (CI), 1.55-24.24] and a low rCBV ratio (rCBV, <0.85; OR, 6.57; 95% CI, 1.4-30.27) was significantly correlated with EPI. Conclusion : The incidence of EPI is considerable in patients with acute MCA territory infarction caused by MCA occlusion. We suggest that rCBV ratio is a useful neuro-imaging parameter to predict EPI.

• Journal of Acupuncture Research
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• 제20권5호
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• pp.172-186
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• 2003

Acupuncture therapy has demonstrated efficacy in several clinical areas, and of these areas the understanding of pain has progressed immensely in the last two decades. The underlying mechanisms of acupuncture in general and the analgesic effect in particular are still not clearly delineated. The leading hypothesis include the effects of local stimulation, neuronal gating, release of endogenous opiates, and the placebo effect. Accumulating evidence suggests that the central nervous system(CNS) is essential for the processing of these effects, via its modulation of the autonomic nervous system, neuro-immune system, and hormonal regulation. These processes tap into basic survival mechanisms. As such, understanding the effects of acupuncture within a neuroscience-based framework becomes vital. We propose a model which incorporates the stress-induced hypothalamus-pituitary-adrenal axis(HPA-axis) model of Akil et al., the cholinergic anti-inflamatory observations of Tracey et al., and Petrovic et al.

• Journal of Korean Neurosurgical Society
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• 제52권3호
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• pp.193-199
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• 2012

Objective : The objective of study is to evaluate the incidence of leptomeningeal carcinomatosis (LMC) in breast cancer patients with parenchymal brain metastases (PBM) and clinical risk factors for the development of LMC. Methods : We retrospectively analyzed 27 patients who had undergone surgical resection (SR) and 156 patients with whole brain radiation therapy (WBRT) as an initial treatment for their PBM from breast cancer in our institution and compared the difference of incidence of LMC according to clinical factors. The diagnosis of LMC was made by cerebrospinal fluid cytology and/or magnetic resonance imaging. Results : A total of 27 patients (14%) in the study population developed LMC at a median of 6.0 months (range, 1.0-50). Ten of 27 patients (37%) developed LMC after SR, whereas 17 of 156 (11%) patients who received WBRT were diagnosed with LMC after the index procedure. The incidence of LMC was significantly higher in the SR group compared with the WBRT group and the hazard ratio was 2.95 (95% confidence interval; 1.33-6.54, p<0.01). Three additional factors were identified in the multivariable analysis : the younger age group (<40 years old), the progressing systemic disease showed significantly increased incidence of LMC, whereas the adjuvant chemotherapy reduce the incidence. Conclusion : There is an increased risk of LMC after SR for PBM from breast cancer compared with WBRT. The young age (<40) and systemic burden of cancer in terms of progressing systemic disease without adjuvant chemotherapy could be additional risk factors for the development of LMC.

• Journal of Korean Neurosurgical Society
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• 제55권1호
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• pp.5-11
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• 2014

Objective : We evaluated pseudoprogression (PsPD) following radiation therapy combined with concurrent temozolomide (TMZ), and we assessed pseudoresponse following anti-angiogenic therapy for patients with recurrent disease using the Response Assessment of the Neuro-Oncology Working Group. Methods : Patients who were pathologically confirmed as having high-grade glioma received radiotherapy with concurrent TMZ followed by adjuvant TMZ. Bevacizumab (Avastin) with CPT-11 were used as a salvage option for cases of radiologic progression. Magnetic resonance imaging (MRI) was routinely performed 1 month after concurrent radiochemotherapy (CRT) and every 3 months thereafter. For cases treated with the bevacizumab-containing regimen for progressive disease, MRI was performed every 2 months. Results : Of 55 patients, 21 (38%) showed radiologic progression within 4 weeks after CRT. Of these patients, 16 (29%) showed progression at second post-CRT MRI (etPD) and five (9%) showed improvement (PsPD). Seven of thirty-four initially non-progressed patients showed progression at the second post-CRT MRI (ltPD). No difference in survival was observed between the etPD and ltPD groups (p=0.595). Five (50%) of ten patients showed a radiological response after salvage bevacizumab therapy. Four of those patients exhibited rapid progression immediately after discontinuation of the drug (drug holiday). Conclusion : Twelve weeks following treatment could be the optimal timing to determine PsPD or true progression. MRI with gadolinium enhancement alone is not sufficient to characterize tumor response or growth. Clinical correlation with adequate follow-up duration and histopathologic validation may be helpful in discriminating PsPD from true progression.

• 대한두경부종양학회지
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• 제12권2호
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• pp.212-216
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• 1996

Four cases of sphenoid sinus carcinoma have been observed for last 10 years and we reviewed English literatures about sphenoid sinus carcinoma. The sphenoid sinus carcinoma is rare and the diagnosis is difficult. In the early stage, the non-specific deep constant headache is the only symptom but if the sinus wall is penetrated, the neuro-ophthalmologic symptoms and signs may appear. The extension of lesion is identified by radiologic imaging and the diagnosis requires direct biopsy. In case of deep constant headache combined with neuro-ophthalmologic symptoms and signs the sphenoid sinus carcinoma should be considered. Our small data reveals that the radiation treatment offers a possibility of relatively good outcome, although most of the cases are advanced already on initial diagnosis.