• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.17-23
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• 2004

Purpose : To evaluate changes in total cerebral blood flow (tCBF) with aging, parenchymal volume changes and vascular abnormalities, using 2 dimensional (D) phase-contrast magnetic resonance imaging (PC MRI). Materials and Methods : Routine brain MRI including T2 weighted image, time-of-flight (TOF) MR Angiography (MRA) and 2D PC MRI were performed in 73 individuals, including 12 volunteers. Normal subjects (12 volunteers, and 21 individuals with normal MRI and normal MRA) were classified into groups according to age (18-29, 30-49 and 50-66 years). For the group with abnormalities in brain MRIs, cerebral parenchymal volume changes were scored according to the T2 weighted images, and atherosclerotic changes were scored according to the MRA findings. Abnormal groups were classified into 4 groups: (i) mild reduction in volume, (ii) marked reduction in volume by parenchymal volume and atherosclerotic changes, and (iii) increased volume and (iv) Moya-moya disease. Volumetric flow was measured at the internal carotid artery (ICA) and vertebral artery bilaterally using the velocity-flow diagrams from PC MRI, and combined 4 vessel flows and tCBF were compared among all the groups. Results : The age-specific distribution of tCBFs in normal subjects were as follows: $12.0{\pm}2.1ml/sec$ in 18-29 years group, $11.8{\pm}1.9ml/sec$ in 30-49 years group, $10.9{\pm}2.2ml/sec$ in 50-66 years group. The distribution of tCBFs in the different subsets of the abnormal population were as follows: $9.5{\pm}2.5ml/sec$ in the group with mild reduction in volume, $7.6{\pm}2.0ml/sec$ in the group with marked reduction in volume, and $7.3{\pm}1.2ml/sec$ and $7.0{\pm}1.1ml/sec$ in the increased parenchymal volume and Moya-moya disease groups respectively. Conclusion : Total cerebral blood flow decreases with increasing age with a concomitant reduction in parenchymal volumes and increasing atherosclerotic changes. It is also reduced in the presence of increased parenchymal volume and Moya-moya disease.2D PC MRI can be used as a tool to evaluate tCBF with aging and in the presence of various conditions that can affect parenchymal volume and cerebral vasculature.

• Journal of Acupuncture Research
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• v.18 no.4
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• pp.46-54
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• 2001

Objective : To study correlation of the brain areas with acupoints used in the treatment of cerebrovascular diseases to evaluate the hypothesis that selecting acupoints on the left side to treat disorders on the right side and vice versa is known as the crossing combination of acupoints. Materials and Methods: Rest/acupuncture-stimulation Tc-99m ECD brain SPECT using a same-dose subtraction method was performed on 5 normal male volunteers (age range from 27 to 30 years) using acupuncture at acupoint, LI4 located in the left hand. In the control study, needle location was chosen on a non-meridian focus 1cm posterior to the right fibular head. All images were spatially normalized and the differences between rest and acupuncture stimulation were statistically analyzed using SPM(R) for Windows(R). Results : Acupuncture applied at LI4 located in the left hand increased rCBF in the right hemisphere, that is, the right parietal lobe(angular gyrus) and a part of the right middle posterior temporal gyrus and the right inferior occipital lobe. In the control stimulation, no significant rCBF increase was observed. Conclusion : The results demonstrated a correlation between stimulation at acupoint with increase in rCBF to the controlateral hemisphere.

• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.56-60
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• 2018

Therapeutic hypothermia in cardiac arrest patients is associated with favorable outcomes mediated via neuroprotective mechanisms. We report a rare case of a 32-year-old male who demonstrated complete recovery of signal changes on perfusion-weighted imaging after therapeutic hypothermia due to cardiac arrest. Brain MRI with perfusion-weighted imaging, performed three days after ending the hypothermia therapy, showed a marked decrease in relative cerebral blood flow (rCBF) and delay in mean transit time (MTT) in the bilateral basal ganglia, thalami, brain stem, cerebellum, occipitoparietal cortex, and frontotemporal cortex. However, no cerebral ischemia was not noted on diffusion-weighted imaging (DWI) or fluid-attenuated inversion recovery (FLAIR) sequences. A follow-up brain MRI after one week showed complete resolution of the perfusion deficit and the patient was discharged without any neurologic sequelae. The mechanism and interpretation of the perfusion changes in cardiac arrest patients treated with therapeutic hypothermia are discussed.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.92-94
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• 1997

By measuring the increase of regional cerebral blood flow (rCBF) during the activation tasks, we can describe the brain regions that participate in certain specific functions. In this study, we composed the functional maps of verbal and nonverbal memory by performing the rCBF positron emission tomography (PET) activation studies and analyzing the differences between control and each activation state. Successive four tasks, which consist of one control state and three different activation tasks, were performed on 6 normal volunteers. All images were spatially normalized on standard atlas and the differences between control and activation states were statistically analyzed. The verbal memory activated predominantly left-sided structures, especially left superior temporal cortex, and the nonverbal short-term memory activated the right frontal cortex. Also, some regions ,where is thought to be related with short-term memory system, such as cingulate gyrus and hippocampus were activated. We conclude that biological validity of the brain regions for verbal and nonverbal memory could be tested using rCBF PET imaging technique and statistical analysis.

• Investigative Magnetic Resonance Imaging
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• v.16 no.2
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• pp.142-151
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• 2012

Purpose : The purpose of this study was to describe arterial spin labeling MR image findings of status epilepticus. Materials and Methods: A retrospective chart review within our institute revealed six patients who had been clinically diagnosed as status epilepticus and had also undergone MR imaging that included ASL in addition to routine sequences. Results: Six patients with status epilepticus were studied by conventional MR and arterial spin labeling imaging. All patients showed increased regional CBF correlating with EEG pathology. Notably, in two patients, conventional MRI and DWI showed no abnormal findings whereas pCASL demonstrated regional increased CBF in both patients. Conclusion: Arterial spin labeling might offer additional diagnostic capabilities in the evaluation of patients with status epilepticus.

• Journal of Acupuncture Research
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• v.21 no.1
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• pp.111-118
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• 2004

Background and purpose: Opposing-needling technique involves selecting acupoints at unaffected limb. The aim of this study was to evaluate the effect of LI4-LI11 electrical acupuncture at unaffected limb on the cerebral blood flow in ischemic stroke patients using SPECT Methods: We selected 9 ischemic stroke patients. Baseline brain SPECT was done with triple head gamma camera(MultiSPECT3, Siemens, USA) after intravenous administration of 925 MBq of Tc-99m ECD). Fifteen-minute electro-acupuncture at Hapgok(LI 4) and Gokji(LI 11) were applied on unaffected upper limb of subjects. The same dose of Tc-99m ECD was injected during the electro-acupuncture, and the second SPECT images were obtained. Using the computer software(ICON 7.1, Siemens, USA), 3 SPECT slices(upper, middle, lower) surrounding the brain lesion were selected and each slice was divided by 10-16 brain regions. Asymmetry indexes were analyzed in each brain region. We regarded$\geq$10% changes of asymmetry index between before and after electro-acupuncture as significance. Results: Seven Patients(77.8%) had significantly increased perfusion and 2(22.2%) didn't show increased perfusion in post-acupuncture scans compared to pre-acupuncture scans(baseline). The regions of CBF improvement were mostly frontal lobes and anterior temporal lobes. Conclusions: This study demonstrated that LI4-LI11 electro-acupuncture at unaffected limb increased regional cerebral blood perfusion to the corresponding brain areas in ischemic stroke patients.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.310-319
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• 1997

This study investigated regional blood flow changes of frontal, temporal, and basal ganglia in eleven schizophrenic patients on DSM-IV criteria to examine the relationship between rCBF and clinical improvement of symptoms. Single-photon emission computed tomography imaging with $^{99m}Tc$-HMPAO was peformed in baseline and sixth weeks after the treatment, and concurrently psychopathology was assessed by PANSS. Antipsychotics wash-out period was more than 2 weeks, and three patient were drug naive. All patients were finally divided into two groups, the improved or not improved. We examined the difference of the amount of rCBF changes between two groups. Finally, frontal activity shows no significant difference between two groups but both groups show decreased frontal blood flow after antipsychotic treatment. However, the change of right temporal rCBF had positive correlation with the change of the total PANSS score, and the change of left temporal lobe activity was greater in the improved group than in the not improved group. Our results suggest that the temporal lobe activity has relation to the underlying schizophrenic symptoms.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.427-428
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• 2009

Optical imaging offers excellent spatio-temporal sensitivity that is unparalleled by any other perfusion based imaging techniques. We used in vivo optical recording of intrinsic signals (ORIS) to map neurovascular hemodynamics of perfusion, oximetry and membrane potential during epileptic events in rat and mouse neocortex. Studies of hemodynamic changes with ORIS alone were also performed in human. Laboratory studies in rodent epilepsy models have demonstrated a persistent increase in deoxygenated hemoglobin (Hbr) and a decrease in tissue oxygenation during interictal spikes and ictal events. This "epileptic dip", like the "initial dip" recorded during normal sensory processing, implies that the enormous rise in cerebral blood flow (CBF) is inadequate to meet the increased metabolic demands associated with synchronized epileptic activity. These findings are critically important to the interpretation of the perfusion-based imaging studies, such as fMRI. In addition, we visualized the effect of direct cortical electrical stimulation, an alterative epilepsy treatment. The optical data following direct cortical electrical stimulation showed that hemodynamic signals are sensitive to different electrical stimulation parameters. Furthermore, our recent data demonstrated that the application of unilateral electrical stimulation is able to elicit bilateral hemodynamic responses in rat neocortex.

• The Korean Journal of Nuclear Medicine
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• v.37 no.2
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• pp.94-102
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• 2003

Purpose : Cerebral blood flow (CBF) reactivity to acetazolamide (ACZ) is useful to select patients with hemodynamic failure. However, it is still a matter of speculation that varying degrees of regional CBF increases after ACZ administration represent the severity or stage of regional hemodynamic failure as assessed by positron emission tomography (PET). We studied to elucidate whether ACZ challenge $^{123}I-IMP$ brain single photon emission tomography (SPECT) can accurately grade the seventy of regional hemodynamic failure. Materials and Methods: Eighteen patients (M: 16, F: 2, average age: 61 years) with unilateral occlusive disease of the internal carotid artery or the trunk of the middle cerebral artery (MCA). Patients undewent $^{123}I-IMP$ brain SPECT study with acetazolamide challenge and PET study was carried out within 2 weeks before and after SPECT study. Five healthy volunteers with a mean age of 48 years (range: 28-73 yr, M: 3, F: 2) underwent PET studies to determine normal values. In SPECT study, an asymmetry index (Al)-the percentage of radioactivity of region of interest (ROI) in the occlusive cerebrovascular lesion to the contralateral homologous ROI-was used for numerical evaluation of relative $^{123}I-IMP$ distribution. In PET study, regional CBF, oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen ($CMRO_2$) and cerebral blood volume (CBV) values were measured with $^{15}O-labeled$ gas inhalation method and the values were used for comparison with Al (Al during acetazolamide challenge-Al of basal study) on the SPECT study. ROls were classified by severity into three groups (normal, stage I and stage II). Results: Mean values of Al in areas with normal, stage I and stage II hemodynamic failure were $6.25{\pm}7.77%\;(n=107),\;-10.38{\pm}10.41%\:(n=117)\;and\;13.30{\pm}10.51%\;(n=140)$, respectively. Al significantly differed with each groups (p<0.05). Correlation between Al and CBF, OEF and CBV/CBF in hemisphere with occlusive cerebrovascular lesion was 0.20 (p<0.01), -0.28 (p<0.01) and -0.28 (p<0.01), respectively. Conclusion: We concluded that $^{123}I-IMP$ brain SPECT with acetazolamide challenge could determine the severity ad stage of regional hemodynamic failure as assessed by PET.

• Dementia and Neurocognitive Disorders
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• v.16 no.3
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• pp.72-77
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• 2017

Background and Purpose Although sleep disturbances are common and considered a major burden for patients with Alzheimer's disease (AD), the fundamental mechanisms underlying the development and maintenance of sleep disturbance in AD patients have yet to be elucidated. The aim of this study was to examine the correlation between regional cerebral blood flow (rCBF) and sleep disturbance in AD patients using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT). Methods A total of 140 AD patients were included in this cross-sectional study. Seventy patients were assigned to the AD with sleep loss (SL) group and the rest were assigned to the AD without SL group. SL was measured using the sleep subscale of the Neuropsychiatric Inventory. A whole-brain voxel-wise analysis of brain SPECT data was conducted to compare the rCBF between the two groups. Results The two groups did not differ in demographic characteristics, severity of dementia, general cognitive function, and neuropsychiatric symptoms, with the exception of sleep disturbances. The SPECT imaging analysis displayed decreased perfusion in the bilateral inferior frontal gyrus, bilateral temporal pole, and right precentral gyrus in the AD patients with SL group compared with the AD patients without SL group. It also revealed increased perfusion in the right precuneus, right occipital pole, and left middle occipital gyrus in the AD with SL group compared with the AD without SL group. Conclusions The AD patients who experienced sleep disturbance had notably decreased perfusion in the frontal and temporal lobes and increased rCBF in the parietal and occipital regions. The findings of this study suggest that functional alterations in these brain areas may be the underlying neural correlates of sleep disturbance in AD patients.