• The Journal of the Korea Contents Association
• /
• v.14 no.12
• /
• pp.854-862
• /
• 2014

Attention deficit hyperactivity disorder (ADHD) students' intellctual defects, learning problems, and poor academic achievements seem to be due to significantly lower intelligence compared to the normal students, but rather the characteristic of inability to pay attention at a given time can be seen as the more attributing reason. In this study, a comparison between the ADHD students and the normal students will be performed using a fMRI analysis in order to differentiate the brain function between the two groups during a working memory task performance and to assess the difference in the activated regions of the brain. Clinical survey examinations and fMRI measurements were performed for a group of 26 elementary students from the Incheon area. The stimulus of fMRI was a working memory. Cartography statistically analyzed parameters and the Statistical Package of Social Sciences using single-sample t-test, two-sample t-test, were analyzed by multiple regression analysis, the statistical significance level was p<0.05 in, respectively. The disproportionate developments could be seen in the ADHD students group such as the frontal cortex, parietal cortex, thalamus, and caudate nucleus, among others. In addition, as some students felt the increase in the difficulty of working memory task performance, the orbitofrontal cortex and the hippocampus were activated, which seems to be the result of an effort for looking for an answer. More types of ADHD students needs to be secured as research subjects, and more stimulations for fMRI experiments should be considered as it would be useful in the overall evaluation of brain function.

• Science of Emotion and Sensibility
• /
• v.22 no.1
• /
• pp.35-44
• /
• 2019

Individuals with problematic hypersexual behavior (PHB) evince the inability to control sexual impulses and arousal. Previous studies have identified that these characteristics are related to structural and functional changes in the brain region responsible for inhibitory functions. However, very little research has been conducted on the functional connectivity of these brain areas during the resting state in individuals with PHB. Therefore, this study used functional magnetic resonance imaging devices with the intention of identifying the deficit of the functional connectivity in the executive control network in individuals with PHB during the resting state. Magnetic resonance imaging data were obtained for 16 individuals with PHB and 19 normal controls with similar demographic characteristics. The areas related to the executive control network (LECN, RECN) were selected as the region of interest, and the correlation coefficient with time series signals between these areas was measured to identify the functional connectivity. Between groups analysis was also used. The results revealed a significant difference in the strength of the functional connectivity of the executive control network between the two groups. In other words, decreased functional connectivity was found between the superior/middle frontal gyrus and the caudate, and between the superior/middle frontal gyrus and the superior parietal gyrus/angular gyrus in individuals with PHB. In addition, these functional Connectivities related to the severity of hypersexual behavior. The findings of this study suggest that the inability to control sexual impulses and arousal in individuals with PHB might be related to the reduced functional connectivity of executive control circuits.

• Journal of Biomedical Engineering Research
• /
• v.25 no.1
• /
• pp.43-47
• /
• 2004

Interests in human brain functionality and its connectivity have much frown up. DTI (Diffusion tensor imaging) has been known as a non-invasive MR) technique capable of providing information on water diffusion in tissues and the organization of white matter tract. Thus. It can provide us the information on the direction of brain fiber tract and the connectivity among many important cortical regions which can not be examined by other anatomical or functional MRI techniques. In this study. was used the 24 bit color coding scheme on the IDL platform in the windows environment to visualize the orientation of major fiber tracts of brain such as main association, projection, commissural fibers and corticospinal tracts. We additionally implemented a color coding scheme for each directional component and FA (fractional anisotropy), and used various color tables for them to be visualized more definitely. Consequently we implemented a fancy and basic technique to visualize the directional information of fiber tracts efficiently and we confirmed the feasibility of the 24 bit color coding scheme in DTI by visualizing main fiber tracts.

• Investigative Magnetic Resonance Imaging
• /
• v.3 no.1
• /
• pp.53-59
• /
• 1999

Purpose : To evaluate the usefulness of functional MR imaging (fMRI) for language mapping and determination of language lateralization. Materials and Methods : Functional maps of the language area were obtained during word generation tasks and decision task in ten volunteers (7 right handed, 3 left-handed). MR examinations were performed at 1.5T scanner with EPI BOLD technique. Each task consisted of three resting periods and two activation periods with each period of 30 seconds. Total acquisition time was 162 sec. SPM program was used for the postprocessing of images. Statistical comparisons were performed by using t-statistics on a pixel-by- pixel basis after global normalization by ANCOVA. Activation areas were topographically analyzed (p>0.001) and activated pixels in each hemisphere were compared quantitatively by lateralization index. Results : Significant activation signals were demonstrated in 9 of 10 volunteers. Activation signals were found in the premotor and motor cortices, the inferior frontal, inferior parietal, and mid-temporal lobes during stimulation tasks. In the right handed seven volunteers, activation of language areas was lateralized to the left side. Verb generation task produced stronger activation in the language areas and higher value of lateralization index than noun generation task or decision task. Conclusion : fMRI could be a useful non-invasive method for language mapping and determination of language dominance.

• Progress in Medical Physics
• /
• v.26 no.2
• /
• pp.72-78
• /
• 2015

Organic solvents are known toxic effects like vertigo, behavioral obstacle, distracting, and peripheral neuropathy in neuron areas. However, there have been few studies how neurotoxic solvents-exposed workers are affected by the cognitive load of preceding working memory tasks. Therefore, we used fMRI as to measure the neural correlates of working memory impairment in occupational workers who had from chronic exposure to organic solvent. Twenty-nine solvent-exposed workers were included in this study. Each participant concluded the verbal N-back tasks (1- and 2-back) during the fMRI acquisition. Within-group analyses showed fronto-parietal networks were active in each condition. Direct comparisons between 1- and 2-back showed higher activation during the 2-back than 1-back. We found that increased activation of these regions at lower task demand is associated with increased cost of implementing.

• Investigative Magnetic Resonance Imaging
• /
• v.12 no.1
• /
• pp.33-39
• /
• 2008

Purpose : There is debate concerning the observation of metabolite changes on MRS at the designated cortex during some tasks. The purpose of this study is to assess the change of the lactate content at the motor cortex during hand-grasping tasks with performing real-time fMRI-guided fMRS. Materials and Methods : Seven healthy volunteers (23-28 years old) underwent realtime fMRI during right hand grasping tasks with using a 1.5 T system. After confirming the activating area, single voxel MRS was preformed at 1) the baseline, 2) during the task and 3) after the task on the activating cortex. The three consecutive spectra were compared for observing the changes of the lactate content by the tasks. The Cho/Cr, NAA/Cr and Lac/Cr ratios were calculated manually from those spectra. Results : MRS during the tasks revealed the lactate peaks at the 1.33 ppm resonance frequency with great conspicuity at the activated area, which was identified on the real-time fMRI. After the task scan, the lactate peaks completely disappeared and the spectra recovered to the values of the baseline scan in all volunteers. At baseline, during the task and after the task, the Cho/Cr ratios were 0.81, 0.76 and 0.77, respectively, and the NAA/Cr ratios were 1.68, 1.65 and 1.72, respectively, and the Lac/Cr ratios were 0.28, 0.41 and 0.30, respectively. During the task, Lac was significantly increased by 46%. Conclusion : We observed prominent lactate peaks on MRS during hand-grasping tasks at the activated area, as was shown on the real-time fMRI. We suggest that fMRS can be used as a sensitive tool for observing the metabolite changes of the functioning brain.

• Journal of Biomedical Engineering Research
• /
• v.21 no.2
• /
• pp.157-163
• /
• 2000

최근 MR영상을 허혈성 뇌졸중의 초급성기에 뇌조직의 관류 이상을 조기에 진단하려는 연구들이 진행되고 있으나 아직 일반적인 진단용 소프트웨어만 있을 뿐 영상 자료를 후처리하여 뇌조직의 구조 및 기능적인 정보를 제공하는 mapping 영상을 특수 소프트웨어는 실용화되어 있지 않다. 본 논문에서는 Gamma-variate 곡선 정합을 이용한 뇌관류 파라미터 영상 mapping의 알고리즘 구현에 관해 연구하였다. 관류 MR영상의 각 화소마다 측정된 시간에 따른 신호강도의 변화 곡선은 비선형적이어서 뇌관류에 관한 여러 가지 혈역학적 변수들을 보다 정확하게 계산할 수 없었다. 그래서 수렴속도가 빠르고 안정성이 높은 비선형 최적화 알고리즘인 Levenberg-Marquardt 알고리즘(LMA)을 활용하였다. 즉 시간에 따른 신호강도의 변화 곡선을 Gamma-variate 함수를 이용하여 곡선 정합한 후, CBV, MTT, CBF, TTP, BAT, MS의 여러 가지 혈역학적 변수를 LMA에 의해 계산하였다. 그 결과로 관류 MR영상으로부터 얻은 mapping 영상은 초급성 허혈성 뇌졸중에서 관류에 관한 혈역학적 변화를 평가함으로써 나중에 생길 뇌경색의 범위를 예견하는 데에 유용하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2001.12a
• /
• pp.251-254
• /
• 2001

본 논문에서는 Self Organizing Map을 이용하여 fMRI data를 분석해 보았다. fMRl (functional Magnetic Resonance Imaging)는 인간의 뇌에 대한 비 침투적 연구 방법 중 최근에 각광받고 있는 것이다. Motor task를 수행하고 있는 피험자로부터 image data를 얻어내어 SOM을 적용하여 clustering한 결과 motor cortex 영역이 뚜렷하게 clustering 되었음을 알 수 있었다.

• Journal of the Korean Society of Radiology
• /
• v.14 no.7
• /
• pp.947-956
• /
• 2020

The human body becomes vulnerable to various diseases due to deterioration in structure and function as it ages. In particular, changes in brain structure weaken the immune system against diseases such as vascular and metabolic neuropsychiatric diseases. In this study, we used a magnetic resonance imaging technique that allows non-invasive observation of brain structures and measurement of how the volumes of the brain, gray matter, white matter, and subcortical regions changes with aging in women aged 65 to 85 years. As a result of our investigation, we observed a significant linear decrease in subcortical regions with age. These results suggest that the changes due to aging in the brain structure area are closely related to neuropsychiatric diseases in old age, and can provide information in understanding the vulnerability of the brain in old age.

• Smart Media Journal
• /
• v.13 no.4
• /
• pp.86-93
• /
• 2024

The development of functional magnetic resonance imaging (fMRI) has significantly contributed to mapping brain functions and understanding brain networks during rest. This paper proposes a CNN-LSTM-based classification model to classify the progression stages of Alzheimer's disease. Firstly, four preprocessing steps are performed to remove noise from the fMRI data before feature extraction. Secondly, the U-Net architecture is utilized to extract spatial features once preprocessing is completed. Thirdly, the extracted spatial features undergo LSTM processing to extract temporal features, ultimately leading to classification. Experiments were conducted by adjusting the temporal dimension of the data. Using 5-fold cross-validation, an average accuracy of 96.4% was achieved, indicating that the proposed method has high potential for identifying the progression of Alzheimer's disease by analyzing fMRI data.