• The Korean Journal of Nuclear Medicine
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• v.34 no.3
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• pp.183-198
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• 2000

Purpose: The purpose of this study was to evaluate alterations of regional cerebral blood flow (CBF) and cerebrovascular reserve (CVR), and correlation between these alternations and cognitive dysfunction in patients with chronic traumatic brain injury (TBI) and normal brain MRI findings. Materials and Methods: Thirty TBI patients and 19 healthy volunteers underwent rest/acetazolamide brain SPECT using Tc-99m HMPAO. Korean-Wechsler Adult Intelligence scale test was also performed in the patient group. Statistical analysis was performed with statistical parametric mapping software (SPM'97) Results: CBF was diminished in the left hemisphere including Wernicke's area in all patients with lower verbal scale scores. In addition, a reduction in CBF in the right frontal, temporal and parietal cortices was related with depressed scores in information, digital span, arithmetic and similarities. In patients with lower performance scale scores, CBF was mainly diminished in the right hemisphere including superior temporal and supramarginal gyri, premotor, primary somatomotor and a part of prefrontal cortices, left frontal lobe and supramarginal gyrus. CVR was diminished in sixty-four Brodmann's areas compared to control. A reduction in CVR was demonstrated bilaterally in the frontal and temporal lobes in patients with lower scores in both verbal and performance tests, and in addition, both inferior parietal and occipital lobes in information subset. Conclusion: Alterations of CBF and CVR were demonstrated in the symptomatic TBI patients with normal MRI finding. These alterations were correlated with the change of intelligence, of which the complex functions are subserved by multiple interconnected cortical structures.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.463-468
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• 1996

본 연구는 간질 병소의 국소화에 있어 발작기 및 발작간 뇌스캔의 정확도를 알아보고 발작기 뇌 스캔에서 나타나는 간질 확산이 정확한 간질 병소를 국소화 하는데 어떠한 영향을 미치는가에 대하여 알아보고자 하였다. 15명의 복잡 부분 발작 환자를 대상으로 하였으며, 간질 병소의 최종적인 국소화는 두피 및 발작 뇌파, 피질 뇌파, 자기 공명 영상, 임상양상 및 병리 소견을 종합한 근거로 하였다. 발작기 뇌스캔은 뇌파상 발작 중 또는 환자가 aura를 호소할 때 Tc-99m HMPAO 20mCi(740 MBq)를 정맥주입후 시행하였으며 발작간 뇌스캔은 발작기 뇌스캔 후 3일 이내 임상적으로 발작 증상이 없는 기간에 시행하였다. 간질 병소는 우측 측두엽이 8예, 좌측 측두엽이 6예, 측두엽 이외의 기원이 1예 였다. 발작기 뇌스캔상, 모두 11예(73.3 %)에서 단발성 또는 다발성 섭취 증가가 간질 병소 및 간질확산 부위에서 관찰되었으며, 간질 병소에만 국한된 섭취 증가는 4예(26.7%)에 불과 하였다. 발작간 뇌스캔에는 모두 11예(73.3 %)에서 간질 병소에만 섭취가 감소되었다. 자기 공명 영상에서는 8예(53.3 %)에서 hippocampal sclerosis를 포함한 간질 병소가 확인되었다. 본 연구로 복잡 부분 발작 환자에서, 간질 확산이 발작기 뇌 스캔 중 자주 관찰됨을 알 수 있었으며, 이러한 간질 확산에 따른 다발성 방사능 섭취가 발작기 뇌스캔상, 간질 병소의 국소화에있어 한계가 있음을 결론 내릴 수 있었다.

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.174-179
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• 2000

Objectives : Cognitive psychological models propose that auditory hallucinations arise from a problem with monitoring one's auditory verbal imagery. Most auditory hallucinations are derogatory in content and accompany negative emotions. If auditory verbal imagery plays an critical role in the pathogenesis of auditory hallucination, it must be influenced by negative emotions. This study was aimed at understanding the influence of negative emotions on the development of hallucinations by investigating the way by which negative emotions have influence on cortical activity induced by auditory verbal imagery. Methods : For both normal subjects and patients with schizophrenia, quantitative electroencephalography(Q-EEG) was applied during the auditory verbal imagery tasks using a two word list. The one word list accompanied negative emotion and the other accompanied neutral emotions. The difference of EEG activity between two tasks was compared by paired t-test. We also compare the difference of the influence of negative emotions between normal subjects and patients with schizophrenia Results : In normal subjects, amplitude of beta wave was increased in temporal area such as TCP1, and, the amplitude of theta frequency wave was decreased in right hemisphere such as FP2, F4, C4, CP2, P4. But, in the schizophrenia group, there were no significant differences. Conclusion : These results may suggest that auditory verbal imagery with negative emotion requires more activation in left temporal area, but, appropriate activation may not achieved in schizophrenia patients. So, the possibility that the resultant disturbance of verbal self monitoring may be related to auditory hallucination is suggested in this study.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.107-111
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• 2009

Purpose: The authors analyzed how the regional cerebral blood flow(rCBF) findings of patients with major depression differ from the normal control, and our results were compared to previous reports. Materials and Methods: Twelve patients fulfilling DSM-IV criteria for major depression who were off all psychotropic medications for > 4weeks(male: 7, female: 5, age range: $19{\sim}52$ years, average age: $29.3{\pm}9.9$ years) and 14 normal volunteers(male: 8, female: 6, age range: $19{\sim}53$ years, average age: $31.4{\pm}9.2$ years) were recruited. Images of brain perfusion SPECT were obtained using Tc-99m ECD and patterns of the rCBF were compared between patients with major depression and the healthy control subjects. Results: The patients with major depression showed increase of the r-CBF in right lingual gyrus, right fusiform gyrus, left lingual gyrus, left precuneus, and left superior temporal gyrus, and showed decrease of r-CBF in right pons, left medial frontal gyrus, cingulate gyrus of left limbic lobe, cingulate gyrus of right frontal lobe, and cingulate gyrus of right limbic lobe compared to the normal control. Conclusion: The Tc-99m ECD brain perfusion SPECT findings in our study did not differ from the previously reported regional cerebral blood flow pattern of patients with major depression. Especially, decreased rCBF pattern typical to major depression patients in the right pons, left medial frontal gyrus, and cingulate regions was clearly demonstrated.

• Pediatric Infection and Vaccine
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• v.25 no.1
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• pp.45-49
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• 2018

Group B streptococcus (GBS) is the leading cause of neonatal morbidity and mortality. Late-onset GBS disease commonly manifests as occult bacteremia or meningitis. Approximately 50% of survivors of late-onset meningitis have long-term neurologic sequelae. Cerebrovascular complications are often associated with unfavorable clinical outcomes of GBS meningitis. There have been a few reports of cerebral infarction accompanied by GBS meningitis. We report a 29-day-old girl with severe, widespread cerebral infarction due to late-onset GBS meningitis. Isolated GBS strain from this patient was serotype III, ST-19. Currently, she has cortical blindness and significant developmental delay.

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.130-138
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• 2011

Purpose : To compare fMRIs of visual and auditory word generation tasks, and to evaluate the difference of its activated areas and lateralization according to the mode of stimuli. Materials and Methods : Eight male normal volunteers were included and all were right handed. Functional maps were obtained during auditory and visual word generation tasks in all. Normalized group analysis were performed in each task and the threshold for significance was set at p<0.05. Activated areas in each task were compared visually and statistically. Results : In both tasks, left dominant activations were demonstrated and were more lateralized in visual task. Both frontal lobes (Broca's area, premotor area, and SMA) and left posterior middle temporal gyrus were activated in both tasks. Extensive bilateral temporal activations were noted in auditory task. Both occipital and parietal activations were demonstrated in visual task. Conclusion : Modality independent areas could be interpreted as a core area of language function. Modality specific areas may be associated with processing of stimuli. Visual task induced more lateralized activation and could be a more useful in language study than auditory task.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.78-83
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• 1999

Purpose : To evaluate the language areas activated by fMRI during different reading tasks and to assess the difference of activated areas according to each reading task. Materials and Methods : Functional maps of the language area were obtained during three reading tasks(Korean consonant letter, pseudoword, and word) in nine right-handed volunteers(7 males 2 females). MR examinations were performed at 1.5T scanner with EPI BOLD technique(gradient echo shot EPI, TR/TE 3000/60, flip angle $90^{\circ}$, matrix $64{\times}64$, 5mm thickness, no slice gap). Each task consisted of three resting periods and two activation periods and each period lasted 30 seconds. We used SPM program for the postprocessing of images and signification level was set at p<0.01. Activated areas were topographically analyzed in each stimulus. Results : Significant activated signals were demonstrated in all volunteers. Activated signals were seen in the frontal, temporal, parietal and occipital lobes during reading tasks and they were lateralized to the left hemisphere except occipital lobe. Letter and pseudoword produced stronger activated signals than word, and the activated signals were more lateralized to the left hemisphere in pseudoword reading than in letter reading. Conclusion : Activated signals were induced in the language areas by reading task of letter or wordform. Greater activation of language areas was induced when letter or pseudowords were presented than familiar words.

• The Korean Journal of Applied Statistics
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• v.37 no.2
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• pp.139-155
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• 2024

This study performed a multi-classification task to classify mesial temporal lobe epilepsy with left hippocampal sclerosis patients (left mTLE), mesial temporal lobe epilepsy with right hippocampal sclerosis (right mTLE), and healthy controls (HC) using magnetoencephalography (MEG) data. We applied various artificial neural networks and compared the results. As a result of modeling with convolutional neural networks (CNN), recurrent neural networks (RNN), and graph neural networks (GNN), the average k-fold accuracy was excellent in the order of CNN-based model, GNN-based model, and RNN-based model. The wall time was excellent in the order of RNN-based model, GNN-based model, and CNN-based model. The graph neural network, which shows good figures in accuracy, performance, and time, and has excellent scalability of network data, is the most suitable model for brain research in the future.

• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.123-130
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• 2001

Objective : Asymmetries in evoked potential P300 topography of schizophrenia and bipolar disorder are still controversial. The purpose of this study was to examine the difference in P300 topography between schizophrenia and bipolar disorder. Method : P300 was recorded from 16 schizophrenic, 15 bipolar manic, and 16 control subjects. All were right-handed. Subjects silently counted target stimuli(2.0kHz) among trains of standard stimuli(1.0kHz). Averages were constructed from brain responses to target stimuli. Results : 1) Schizophrenics displayed significantly smaller peak amplitude of P300 over Cz, Pz, T3 than controls. 2) Schizophrenics displayed significantly smaller peak amplitude of P300 over T3 than bipolar manics. 3) Schizophrenics displayed significantly smaller peak amplitude of P300 over T3 than their T4. 4) Schizophrenics displayed significantly delayed latency of P300 over T3 than bipolar manics. 5) Schizophrenics displayed significantly delayed latency of P300 over T3 than their T4. Conclusions : Left-sided P300 abnormality, especially left superior temporal gyrus, in schizophrenics relative to bipolar manics and controls suggests that psychophysiological cause of schizophrenia and bipolar disorder is different and P300 asymmetry is specific to the psychophysiological cause of schizophrenia.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.10-21
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• 2000

Purpose: Episodic memory is described as an 'autobiographical' memory responsible for storing a record of the events in our lives. We performed functional brain activation study using ${H_2}^{15}O$ PET to reveal the neural basis of the encoding and the retrieval of episodic memory in human normal volunteers. Materials and Methods: Four repeated ${H_2}^{15}O$ PET scans with two reference and two activation tasks were performed on 6 normal volunteers to activate brain areas engaged in encoding and retrieval with verbal materials. Images from the same subject were spatially registered and normalized using linear and nonlinear transformation. Using the means and variances for every condition which were adjusted with analysis of covariance, t-statistic analysis were performed voxel-wise. Results: Encoding of episodic memory activated the opercular and triangular parts of left inferior frontal gyrus, right prefrontal cortex, medial frontal area, cingulate gyrus, posterior middle and inferior temporal gyri, and cerebellum, and both primary visual and visual association areas. Retrieval of episodic memory activated the triangular part of left inferior frontal gyrus and inferior temporal gyrus, right prefrontal cortex and medial temporal area, and both cerebellum and primary visual and visual association areas. The activations in the opercular part of left inferior frontal gyrus and the right prefrontal cortex meant the essential role of these areas in the encoding and retrieval of episodic memory. Conclusion: We could localize the neural basis of the encoding and retrieval of episodic memory using ${H_2}^{15}O$ PET, which was partly consistent with the hypothesis of hemispheric encoding/retrieval asymmetry.