• 한국지능시스템학회:학술대회논문집
• /
• 한국지능시스템학회 2007년도 추계학술대회 학술발표 논문집
• /
• pp.7-10
• /
• 2007

많은 과학자들은 인간의 사고를 functional Magnetic Resonance Imaging (fMRI), Time Resolved Spectroscopy(TRS), Electroencephalography(EEG)등을 이용해서 두뇌 활동 영역을 연구하고 있다. 주로 의학 분야와 심리학의 영역에서 두뇌의 활동을 연구하여 간질이나 발작을 알아내고 거짓말 탐지 분야에서도 사용된다. 본 논문에서는 사람의 두뇌활동을 측정하여 인간의 감정을 인식하는 연구에 중점을 두었다. 특히 fMRI와 TRS 그리고 EEG를 이용해서 사람의 두뇌활동을 측정하는 연구를 하였다. 많은 연구자들이 한 가지 측정 장치만을 사용하여서 측정하거나 fMRI와 EEG를 동시에 측정하는 연구를 진행하고 있다. 현재에는 단순히 두뇌의 활동을 측정하거나 측정시 발생하는 잡음들을 제거하는 연구들에 중점을 두고 진행되고 있다. 본 연구에서는 fMRI와 TRS를 동시에 측정하여 얻은 두뇌 활동 데이터를 가지고 감정에 따른 활동영역의 EEG신호를 측정하였다. EEG 신호분석에 있어서 기존의 뇌파만을 가지고 특정을 찾아내는 것을 넘어서 각각의 채널에서 기록되는 뇌파의 파형을 주파수에 따라서 분류하고 정확한 측정을 위해 낮은 주파수를 제거하고 연구자가 필요한 부분의 뇌파를 분석하였다.

• Journal of Korean Neurosurgical Society
• /
• 제52권3호
• /
• pp.273-276
• /
• 2012

Metronidazole-induced encephalopathy is a very rare complication of the long standing use of metronidazole. The encephalopathy is bilateral and symmetric in nature. We report on the magnetic resonance imaging (MRI) and clinical course of metronidazole-induced encephalopathy in a 60-year-old female with a persistent anaerobic brain abscess after draining of the abscess. After 3 months of metronidazole administration, the patient complained of dysarthria, tingling sense of all extremities, and left hemiparesis. MRI revealed symmetric hyperintensity lesions in medulla, pons, dentate nuclei of cerebellum, and splenium of corpus callosum, all of which represent typical findings of metronidazole-induced encephalopathy. In addition, asymmetric lesions in midbrain, thalamus, putamen and cerebral subcortical white matter were noted. The patient recovered after discontinuation of metronidazole and the remaining abscess was successfully treated with meropenem and levofloxacine.

• Journal of Magnetics
• /
• 제21권2호
• /
• pp.281-285
• /
• 2016

The purpose of study was to evaluate SNR and CNR with different contrast agent contents (1.0 mmol/mL gadobutrol and 0.5 mmol/mL gadoterate meglumine) for spin echo (SE) and 3-dimension contrast-enhanced fast field echo (3D CE-FFE) pulse sequences. In this study, we compared the SNR and the CNR between 0.5 mmol/mL gadoterate meglumine and 1.0 mmol/mL gadobutrol according to the concentration of contrast agent in brain MRI. When we compared between SE and 3D CE-FFE pulse sequences, the higher SNR and CNR using 3D CE-FFE pulse sequence can be acquire regardless of contrast agent contents. Also, a statistically significant difference was found for SNR and CNR between all protocols. In conclusion, our results demonstrated that the SNR and CNR have not risen proportionately with contrast agent contents. We hope that these results presented in this paper will contribute to decide contrast agent contents for brain MRI.

• 스마트미디어저널
• /
• 제13권4호
• /
• pp.86-93
• /
• 2024

기능적 자기 공명영상(functional magnetic resonance imaging;fMRI)의 발전은 뇌 기능의 매핑, 휴식 상태에서 뇌 네트워크의 이해에 상당한 기여를 하였다. 본 논문은 알츠하이머의 진행상태를 분류하기 위해 CNN-LSTM 기반의 분류 모델을 제안한다. 첫 번째로 특징 추출 이전 fMRI 데이터에서 잡음을 제거하기 위해 4단계의 전처리를 수행한다. 두 번째, 전처리가 끝나면 U-Net 구조를 활용하여 공간적 특징을 추출한다. 세 번째, 추출된 공간적 특징은 LSTM을 활용하여 시간적 특징을 추출하여 최종적으로 분류하는 과정을 거친다. 실험은 데이터의 시간차원을 조절하여 진행하였다. 5-fold 교차 검증을 사용하여 평균 96.4%의 정확도를 달성하였고 이러한 결과는 제안된 방법이 fMRI 데이터를 분석하여 알츠하이머의 진행을 식별하는데 높은 잠재력을 가지고 있음을 보여준다.

• Annals of Clinical Neurophysiology
• /
• 제16권1호
• /
• pp.1-7
• /
• 2014

Iron is an important element for brain oxygen transport, myelination, DNA synthesis and neurotransmission. However, excessive iron can generate reactive oxygen species and contribute neurotoxicity. Although brain iron deposition is the natural process with normal aging, excessive iron accumulation is also observed in various neurological disorders such as neurodegeneration with brain iron accumulation, Parkinson's disease, Alzheimer's disease, multiple sclerosis, Friedreich ataxia, and others. Magnetic resonance image (MRI) is a useful method for detecting iron deposits in the brain. It can be a powerful tool for diagnosis and monitoring, while furthering our understanding of the role of iron in the pathophysiology of a disease. In this review, we will introduce the mechanism of iron toxicity and the basics of several iron-related MRI techniques. Also, we will summarize the previous results concerning the clinical application of such MR imagings in various neurological disorders.

• Annals of Clinical Neurophysiology
• /
• 제18권1호
• /
• pp.18-20
• /
• 2016

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degenerative disease that clinically manifests both upper and lower motor neuron signs. However, it is unknown where and how the motor neuron degeneration begins, and conflicting hypotheses have been suggested. Recent advanced radiological techniques enable us to look into ALS neuropathology in vivo. Herein, we report a case with upper motor neuron-predominant ALS in whom the results of brain magnetic resonance imaging (MRI) and myelin water fraction MRI suggest axonal degeneration.

• Investigative Magnetic Resonance Imaging
• /
• 제18권2호
• /
• pp.167-170
• /
• 2014

내측세로다발은 조화로운 눈운동의 핵심적인 역할을 하는 유수 합성로이며 수도관주위회색질의 배쪽의 중간선 근처에 놓여있다. 내측세로다발의 병변은 신경핵사이 눈근육마비로 불리는 동측의 내전 결손과 반대측 외전 안진을 야기한다. 중뇌와 교뇌에서 인접한 백질과 섞여있는 신경로는 전산화단층촬영술과 자기공명영상과 같은 뇌영상에서 구별하기 어렵다. 지금까지 우리가 알기로는 내측세로다발은 실제 자기공명영상에서 구체적으로 묘사되지 않았다. 우리는 염증성 탈수초성 질환에서 자기공명영상에 내측세로다발의 전체 연결 과정을 보이는 증례를 보고한다.

• Investigative Magnetic Resonance Imaging
• /
• 제21권4호
• /
• pp.199-209
• /
• 2017

Purpose: Caffeine is the most widely consumed psychostimulant. It is often adopted as a tool to modulate brain activations in fMRI studies. However, its pharmaceutical effect on task-induced deactivation has not been fully examined in fMRI. Therefore, the purpose of this study was to examine the effect of caffeine on both activation and deactivation under sustained attention. Materials and Methods: Task fMRI was acquired from 26 caffeine naive healthy volunteers before and after taking caffeine pill (200 mg). Results: Statistical analysis showed an increase in cognition-load dependent task activation but a decrease in load dependent de-activation after caffeine ingestion. Increase of attention and memory task activation and its load-dependence suggest a beneficial effect of caffeine on the brain even though it has no overt behavior improvement. The reduction of deactivation by caffeine and its load-dependence indicate reduced facilitation from task-negative networks. Conclusion: Caffeine affects brain activity in a load-dependent manner accompanied by a disassociation between task-positive network and task-negative network.

• Investigative Magnetic Resonance Imaging
• /
• 제26권2호
• /
• pp.96-103
• /
• 2022

Purpose: The survival of organisms critically depends on avoidance responses to life-threatening stimuli. Information about dangerous situations needs to be remembered to produce defensive behavior. To investigate underlying brain regions to process information of danger, manganese-enhanced MRI (MEMRI) was used in olfactory fear-conditioned rats. Materials and Methods: Fear conditioning was conducted in male Sprague-Dawley rats. The animals received nasal injections of manganese chloride solution to monitor brain activation for olfactory information processing. Twenty-four hours after manganese injection, rats were exposed to electric foot shocks with odor cue for one hour. Control rats were exposed to the same odor cue without foot shocks. Forty-eight hours after the conditioning, rats were anesthetized and their brains were scanned with 9.4T MRI. Acquired images were processed and statistical analyses were performed using AFNI. Results: Manganese injection enhanced brain areas involved in olfactory information pathways in T1 weighted images. Rats that received foot shocks showed higher brain activation in the central nucleus of the amygdala, septum, primary motor cortex, and preoptic area. In contrast, control rats displayed greater signals in the orbital cortex and nucleus accumbens. Conclusion: Nasal delivery of manganese solution enhanced olfactory signal pathways in rats. Odor cue paired with foot shocks activated amygdala, the central brain region in fear, and related brain circuits. Use of MEMRI in fear conditioning provides a reliable monitoring technique of brain activation for fear learning.

• Journal of Korean Neurosurgical Society
• /
• 제51권5호
• /
• pp.312-315
• /
• 2012

We report magnetic resonance image (MRI) and magnetic resonance spectroscopy (MRS) findings in a patient of cerebral fat embolism (CFE) occurred in a 26-year-old woman after an autologous fat injection into the face. After initial neurologic symptom onset, MRI and MRS data were obtained two times to investigate repeated CFE. We obtained the MRS data in the two different time intervals and two different echo times to compare the lesions with normal brain parenchyma. The results of MRS data showed that a decrease in N-acetyl-aspartate, an increase in lactate and a very high early peak of free lipids between 0.9 and 1.4 ppm were obtained at the acute infarcted lesion as compared with normal brain parenchyma. In addition, these findings were more clearly detected on short echo time spectrum rather than long spectrum. A close relationship between the clinical manifestations and MRI and MRS findings of the brain can helpful to distinguish CFE with other conditions and to evaluate the cause materials of infarctions rather than conventional MRI or diffusion-weighted imaging.