• 대한핵의학회:학술대회논문집
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• 대한핵의학회 2001년도 제40차 추계학술대회 및 총회
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• pp.33.2-33.2
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• 2001

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5311-5316
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• 2012

뇌 영상분석 알고리즘 적용에 따른 뇌혈류의 변화를 관찰하기 위해 정상 성인 13명(평균연령 39세)을 대상으로 뇌혈류 단 광자 단층촬영(Single Photon Emission Computed Tomography, SPECT)을 시행하였다. 획득된 영상을 여과후 역투영법(Filtered Back Projection, FBP)과 반복적 방법(Ordered Subset Expectation Maximization, OSEM)으로 영상을 재구성하여 통계학적 파라미터 뇌지도법으로 비교하여 방사성 의약품의 뇌 분포양상을 확인하였으며, 혈류의 변화는 크러스트(Cluster)로 표현시켰다. 이에 대한 결과로는 여과후 역투영법이 반복적 방법보다 섭취가 증가된 부위는 우측 전두엽, 대뇌회전하부, 외핵, 좌측대뇌 변엽과 대상이랑이며, 섭취가 감소된 부위는 좌측전두엽, 중간전두이랑, 하측전두이랑, 중심전이랑, 하측전두이랑, 중심전이랑이었다. 이는 영상재구성시 적용되는 알고리즘에 따라 뇌 혈류분포가 다르게 나타난 것을 크러스트(Cluster)로 표현시켰고, 명확한 시각적 표시가 가능하도록 뇌 확룔 지도로 보여주는데 의의가 있다.

• 한국자기공명학회논문지
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• 제6권1호
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• pp.45-53
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• 2002

Objectives: This study investigated alterations in regional cerebral blood flow (rCBF) in patients with transient global amnesia (TGA) using statistical parametric mapping 99 (SPM99). Methods: Noninvasive rCBF measurements using 99mTc-ethyl cysteinate dimer (ECD) SPECT were performed on 8 patients with TGA who have ongoing symptoms and 17 age matched controls. The relative rCBF maps in patients with TGA and controls were compared. Results: In patients with TGA, significant decreased rCBF was found along the L superior temporal extending to L parietal region of the brain and L thalamus. There were areas of increased rCBF in the R temporal, R frontal region and R thalamus. Conclusion: We could demonstrate decreased perfusion in left cerebral hemisphere and increased perfusion in right cerebral hemisphere in patients with TGA using SPM99. The imbalanced change of rCBF between bilateral cerebral hemisphere in patients with TGA might suggest that imbalanced neuronal activity between the bilateral hemispheres may have strong relationship to the pathogenesis of the TGA. For quantitative SPECT analysis in TGA patients, we recommend SPM99 rather than the ROI method because of its definitive advantages.

• 대한방사선기술학회지:방사선기술과학
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• 제26권2호
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• pp.71-78
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• 2003

SPM99를 이용한 뇌지도 작성 과정에서 각각의 뇌 영상을 SPM99에서 제공하는 template image와 소아의 영상으로 만든 template image로 각각 공간 규격화하였을때 소아 ADHD 환자의 정상인 소아와 환자 그룹간의 비교를 실행하여 뇌혈류의 변화를 분석, 결과를 비교하였다. P-value를 0.05로 하였을 때 SPM99에서 제공하는 template image로 규격화하여 t-test를 한 결과 Inter-hemispheric 부근과 대뇌 후두엽에서 혈류량이 증가하는 것을 볼 수 있으나 12명의 정상 소아의 평균 image로 만든 template image로 규격화한 결과의 경우 좌뇌(Left Cerebrum)의 두정엽(Parietal Lobe)에서 또 다른 혈류량증가의 cluster가 나타났다.

• 생물정신의학
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• 제9권2호
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• pp.152-158
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• 2002

Background & Purpose:Neuropsychological disorders after traumatic brain injury(TBI) are poorly correlated with structural lesions detected by structural neuroimaging techniques such as computed tomography(CT) scan or magnetic resonance imaging(MRI). It is well known that patients with TBI have cognitive and behavioral disorders even in the absence of structural lesions of the brain. This study investigated whether there are abnormalities of regional cerebral blood flow(rCBF) in TBI patients without structural abnormality on MRI, using technetium 99m ethyl cysteinate dimer(Tc-99m-ECD) single photon emission computed tomography(SPECT) scans. Materials and Methods:Twenty-eight TBI patients without structural abnormality on MRI(mild, n=13/moderate, n=9/severe, n=6) and fifteen normal controls were scanned by SPECT. A voxel-based analysis using statistical parametric mapping(SPM) was performed to compare the patients with the normal controls. Results:rCBF was reduced in the right uncus and the right lateral orbitofrontal gyrus in the TBI patients. However, no increase of rCBF was noted in the patients in comparison to the normal controls. Conclusions:These results suggest that the TBI patients, even in the absence of structural lesion of the brain, may have dysfunction of the brain, particularly of the orbitofrontal and anterior pole of the temporal cortex. They also suggest that SPECT can be a useful method to identify brain dysfunctions in combination with structural brain imaging and neuropsychological tests.

• 대한한의학회지
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• 제29권4호
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• pp.205-212
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• 2008

Background and purpose: So far it was reported that acupuncture increased cerebral blood supply and stimulated the functional activity of brain nerve cells. A previous study demonstrated a correlation between LI4-11 electro-acupuncture (EA) and rCBF increase in frontal lobe. However, there remained a need to study further using various controls in acupuncture research. Transcutaneous electrical nerve stimulation (TENS) has been used as a non-invasive control in acupuncture study. This study was to evaluate the effect of LI4-LI11 TENS on regional cerebral blood flow (rCBF) in normal volunteers using single photon emission computed tomography (SPECT) and statistical parametric mapping (SPM). Methods: In the resting state, $^{99m}Tc-ECD$ brain SPECT scans were performed on 10 normal volunteers (9 males, 1 female, mean age 26.6$\pm$0.5 years; age range from 26 to 27 years). On the other day, 7 days after the resting examination, 15 minute TENS were applied at LI 4 and LI 11 on the right side of the subjects. Immediately after LI4-LI11 TENS, the second SPECT images were obtained in the same manner as the resting state. Significant increases and decreases of regional cerebral blood flow after LI4-LI11 TENS were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by statistical parametric mapping with a threshold of p = 0.001, uncorrected (extent threshold: k=100 voxels). Results: TENS applied at right LI4-LI11 increased rCBF in the left somatosensory association cortex (Brodmann area 5, 7). However there was no area where LI4-11 TENS decreased rCBF. Conclusion and suggestions: These results demonstrate that right LI4-LI11 TENS increased rCBF only in corresponding somatosensory association cortex, which was different from the previous results using LI4-11 EA. It is suggested that there be a different mechanism between TENS and EA.

• Nuclear Medicine and Molecular Imaging
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• 제41권2호
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• pp.71-77
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• 2007

Advance of neuroimaging technique has greatly influenced recent brain research field. Among various neuroimaging modalities, positron emission tomography has played a key role in molecular neuroimaging though functional MRI has taken over its role in the cognitive neuroscience. As the analysis technique for PET data is more sophisticated, the complexity of the method is more increasing. Despite the wide usage of the neuroimaging techniques, the assumption and limitation of procedures have not often been dealt with for the clinician and researchers, which might be critical for reliability and interpretation of the results. In the current paper, steps of voxel-based statistical analysis of PET including preprocessing, intensity normalization, spatial normalization, and partial volume correction will be revisited in terms of the principles and limitations. Additionally, new image analysis techniques such as surface-based PET analysis, correlational analysis and multimodal imaging by combining PET and DTI, PET and TMS or EEG will also be discussed.

• 생물정신의학
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• 제10권2호
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• pp.168-176
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• 2003

Objectives:We investigated the characteristics of P300 generators in obsessive-compulsive disorder(OCD) patients by using voxel-based statistical parametric mapping of current density images. Methods:P300 generators, produced by a rare target tone of 1500Hz under a frequent non-target tone of 1,000Hz, were measured in 15 right-handed OCD patients and 15 controls. Low Resolution Electromagnetic Tomography(LORETA), using a realistic head model of the boundary element method based on individual MRI, was applied to the 128-channel EEG. Statistical parametric mapping(SPM) was applied for the statistical analysis. Results:We found that both groups had the mean current density of P300 in the parietal, temporal and prefrontal lobe. There was a trend for decreased current density in the prefrontal area in OCD patients. The statistical comparison showed current density increase in the supraparietal area, a statistically significant longer P300 latency and a trend for reduced P300 amplitude in OCD patients. Conclusion:It suggests that P300 source of both groups exists in multiple brain regions at the same time. And both groups had no statistically significant differences in the current density of P300 except for increased current density in the supraparietal area in OCD patients. But, considering the statistically significant longer P300 latency, a trend for reduced P300 amplitude and relative mean current density reduction in the prefrontal area in OCD patients, this study suggests that the frontal lobe may have a reduced normal inhibitory process in OCD patients.

• 한국인지과학회:학술대회논문집
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• 한국인지과학회 2005년도 춘계학술대회
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• pp.151-153
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• 2005

We investigated the brain substrate of repetition priming on the implicit memory taskusing low-resolution electromagnetic tomography (LORETA) with high-density 128 channel EEG and individual MRI as a realistic head model. Thirteen right-handed, healthy subjects performed a word/nonword discrimination task, in which the words and nonwords were presented visually,and some of the words appeared twice with a lag of one or five items. All of the subjects exhibited repetition priming with respect to the behavioral data, in which a faster reaction time was observed to the repeated word (old word) than to the first presentation of the word (new word). The old words elicited more positive-going potentials than the new words, beginning at 200 ms and lasting until 500 ms post-stimulus. We conducted source reconstruction using LORETA at a latency of 400 ms with the peak mean global field potentials and used statistical parametric mapping for the statistical analysis. We found that the source elicited by the old words exhibited a statistically significant current density reduction in the left inferior frontal gyrus. This is the first study to investigate the generators of repetition priming using voxel-by-voxel statistical mapping of the current density with individual MRI and high-density EEG.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제19권1호
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• pp.13-18
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• 2008

Objectives : Internet addiction or pathologic internet use is one of the major mental health problems in children and adolescents in Korea. Internet addiction is defined as uncontrollable, markedly time-consuming internet use, which lasts for a period of at least six months. Internet addiction results in poor academic performance and negative parent-child relationships. By using $^{18}F$-fluorodeoxyglucose-positron emission tomography (FDG-PET), we investigated the effects of internet addiction on functional changes occurring in the adolescent brain. Methods : Adolescent patients with an internet addiction (4 boys and 2 girls; $15.6{\pm}1.2$ years) participated in this study. Eight healthy young adults (5 males and 3 females; 18-30 years old) with no previous history of psychiatric illness also participated as normal controls. Brain FDG-PET data was obtained with the participants in the resting condition and with no addictive stimuli. Results : Statistic parametric mapping analysis of the brain FDG-PET data revealed hypometabolic changes in the visual information processing circuits and hypermetabolic changes in the prefrontal areas in the adolescents with internet addiction, as compared with normal controls (p<.001). Conclusion : These results suggest a neuronal adaptation to excessive visual stimulation and synaptic plasticity due to internet addiction.