• Progress in Medical Physics
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• v.14 no.1
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• pp.34-42
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• 2003

In medical imaging, three-dimensional (3D) display using Virtual Reality Modeling Language (VRML) as a portable file format can give intuitive information more efficiently on the World Wide Web (WWW). The web-based 3D visualization of functional images combined with anatomical images has not studied much in systematic ways. The goal of this study was to achieve a simultaneous observation of 3D anatomic and functional models with planar images on the WWW, providing their locational information in 3D space with a measuring implement using VRML. MRI and ictal-interictal SPECT images were obtained from one epileptic patient. Subtraction ictal SPECT co-registered to MRI (SISCOM) was performed to improve identification of a seizure focus. SISCOM image volumes were held by thresholds above one standard deviation (1-SD) and two standard deviations (2-SD). SISCOM foci and boundaries of gray matter, white matter, and cerebrospinal fluid (CSF) in the MRI volume were segmented and rendered to VRML polygonal surfaces by marching cube algorithm. Line profiles of x and y-axis that represent real lengths on an image were acquired and their maximum lengths were the same as 211.67 mm. The real size vs. the rendered VRML surface size was approximately the ratio of 1 to 605.9. A VRML measuring tool was made and merged with previous VRML surfaces. User interface tools were embedded with Java Script routines to display MRI planar images as cross sections of 3D surface models and to set transparencies of 3D surface models. When transparencies of 3D surface models were properly controlled, a fused display of the brain geometry with 3D distributions of focal activated regions provided intuitively spatial correlations among three 3D surface models. The epileptic seizure focus was in the right temporal lobe of the brain. The real position of the seizure focus could be verified by the VRML measuring tool and the anatomy corresponding to the seizure focus could be confirmed by MRI planar images crossing 3D surface models. The VRML application developed in this study may have several advantages. Firstly, 3D fused display and control of anatomic and functional image were achieved on the m. Secondly, the vector analysis of a 3D surface model was defined by the VRML measuring tool based on the real size. Finally, the anatomy corresponding to the seizure focus was intuitively detected by correlations with MRI images. Our web based visualization of 3-D fusion image and its localization will be a help to online research and education in diagnostic radiology, therapeutic radiology, and surgery applications.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.2
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• pp.155-163
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• 2019

Objectives : The aim of this study was to compare severity, neurocognitive functions, and behavioral and psychological symptoms of dementia (BPSD) according to the degree of temporal lobe atrophy (MTA) in Korean patients with dementia due to Alzheimer's disease and mild cognitive impairment due to Alzheimer's disease. Methods : Participants were 114 elderly subjects diagnosed with Alzheimer's disease or mild cognitive impairment in this cross-sectional study. MTA in brain MRI was rated with standardized visual rating scales (Scheltens scale) and the subjects were divided into two groups according to Scheltens scale. Severity was evaluated with Clinical Dementia Rating (CDR) and Global Deterioration Scale (GDS). Neurocognitive functions was evaluated with the Korean version of Short Blessed Test (SBT-K) and the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease assessment packet (CERAD-K). BPSD was evaluated with the Korean version of the Neuropsychiatric Inventory (K-NPI). Independent t-test was performed to compare severity, neurocognitive functions, and BPSD between two groups. Results : The group with high severity of MTA showed significantly lower scores in CDR, SBT-K, MMSE-KC, modified Boston naming test, word list recognition, and word list memory (p<0.05). There were no differences in K-NPI scores between two groups. Conclusions : Severity and neurocognitive functions of dementia had significant positive association with MTA, but BPSD had no association with MTA. Evaluating MTA seems to have potential benefit in diagnosing and treating neurocognitive impairments in the elderly. Further evaluation is needed to confirm the association between certain brain structures and BPSD.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.127-132
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• 2010

The purpose of this study is to measure scattered ray which is occurred except for Z-axis range of the detector in MDCT's iso-center and present the basic data about the standard for reduction of scattered ray. The development of MDCT brings out the enlargement of beam thickness to the patient's Z-axis, which distributes to the increase in exposure dose according to the rise of scattered ray. Also MDCT brings out the increase of scattered ray about 4times more than SDCT. To evaluate scattered ray according to the change of beam thickness on MDCT, we measured scattered ray of MDCT's Z-axis beam thickness by using one 16-slice CTs and two 64-slice CTs. We used the ionization chamber 60ml 2026C as the equipment of measurement. In our results, we found out that the change of scattered ray according to the beam thickness in the same kVp has increase of scattered ray. Secondly we found out the increase of scattered ray according to the increase of kVp. Lastly we found out the decrease of scattered ray according to the increase of the distance from the ionization chamber.

• Sleep Medicine and Psychophysiology
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• v.3 no.1
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• pp.68-78
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• 1996

Objective : The Mini-Mental State Examination(MMSE) and Brief Cognitive Rating Scale(BCRS) are frequently using screening tests fur evaluating the cognitive function in clinical practice and research. The authors tried to evaluate the clinical usefulness of these tests for the patients with non-traumatic subcortical cerebrovascular disease. Method : We administered the MMSE and BCRS to 85 patients and 195 normal control group. In order to compare the test results according to the lesion site, we divided patients into left sided lesion group(21 patients), right sided lesion group(31 patients) and both sided lesion group(13 patients). Their cognitive function was evaluated by the BNA and daily living functional activity was examined by the IADLs(Instrumental Activities of Daily Living Scale)and GERRI(Geriatric Evaluation by Relative's Rating Instrument). Results : The results are as follows : 1) In the BNA, the patients scored significantly lower than control group at all items(except Right-Left Orientation and Motor Impersistence), but there were no difference in the MMSE(total score and all 5 items), and only 2 items(recent memory and self-care) were significantly different between two groups in the BCRS. 2) In the comparison by lateralization, there were significant differences among three groups at 3 items(Left Tactile Form Perception, Left Finger Localization and Right Finger Localization) in the BNA. But, there were no difference in the MMSE and BCRS. 3) In the correlation between daily living functioning and the MMSE/BCRS, control group showed no relation(except item of cognitive functioning), but patient group was significantly correlated with 3 items(social functioning, instrumental activities of daily living and cognitive functioning). Conclusions : These findings suggest that MMSE and BCRS are not useful as the test for cognitive function and discrimination of lateralization in patients with non-traumatic subcortical cerebrovascular disease. However, scores of these tests may be related with the functional level(such as daily living function) of patients.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.365-373
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• 1999

Background: Despite widespread use of tracheostomy in intensive care unit, it is still controversial to define the best timing from endotracheal intubation to tracheostomy under prolonged mechanical ventilation. Early tracheostomy has an advantage of easy airway maintenance and enhanced patient mobility whereas a disadvantage in view of nosocomial infection and tracheal stenosis. However, there is a controversy about the proper timing of tracheostomy. Methods: We conducted a retrospective study of the 35 medical and 15 surgical ICU patients who had admitted to Ewha Womans University Mokdong Hospital from January 1996 to August 1998 with the observation of APACHE III score, occurrence of nosocomial infections, and clinical outcomes during 28 days from tracheostomy in terms of early (n=25) vs. late (n=25) tracheostomy. We defined the reference day of early and late tracheostomy as 7th day from intubation. Results: The number of patients were 25 each in early and late tracheostomy group. The mean age were $48{\pm}18$ years in early tracheostomy group and $63{\pm}17$ years in late tracheostomy group, showing younger in early tracheostomy group. The median duration of intubation prior to tracheostomy was 3 days and 13 days in early and late tracheostomy groups. Organs that caused primary problem were nervous system in 27 cases(54%), pulmonary 14(28%), cardiovascular 4(8%), gastrointestinal 4(8%) and genitourinary 1(2%) in the decreasing order. Prolonged ventilation was the most common reason for the purpose of tracheostomy in both groups. APACHE m scores at each time of intubation and tracheostomy were slightly higher in late tracheostomy group but not significant statistically. Day to day APACHE III scores were not different between two groups with observation upto 7th day after tracheostomy, Occurrence of nosocomial infections, weaning from mechanical ventilation, and mortality showed no significant difference between two groups with observation of 28 days from tracheostomy. The mortality was increased as the APACHE m score upto 7 days after tracheostomy increased, but there were no increment for the mortality in terms of the time of tracheostomy and the days of ventilator use before tracheostomy, Conclusion: The early tracheostomy seems to have no benefit with respect to severity of illness, nosocomial infection, duration of ventilatory support, and mortality. It suggests that the time of tracheostomy is better to be decided on clinical judgement in each case. And in near future, prospective, randomized case-control study is required to confirm these results.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.428-433
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• 2012

Probiotics and their products, such as yogurt and cheese have been widely consumed in many countries with proven health benefits including anti-microbial activity and anti-diarrheal activity. LHFM (Lactobacillus helveticus - fermented milk) is a processed skim milk powder, fermented by a probiotics, L. helveticus IDCC3801. In the present study, we aimed to investigate the neuroprotective effects and the cognitive improvements of LHFM. LHFM itself did not show any cytotoxicity to the human neuroblastoma cell line, SH-SY5Y; however, it dose-dependently protected against glutamate-induced neuronal cell death. LHFM also attenuated scopolamine-induced memory deficit in Y-maze and Morris-water maze. In the analysis of hippocampus after a behavior test, LHFM significantly increased the acetylcholine level and also inhibited acetylcholine esterase activity. Therefore, the raised acetylcholine release partially contributes to the improvement of learning and memory by a treatment with LHFM. These results suggest that LHFM is an effective material for prevention or improvement of cognitive impairments caused by neuronal cell damage and central cholinergic dysfunction.

• Korean Journal of Biological Psychiatry
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• v.6 no.2
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• pp.153-160
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• 1999

Animal models can provide a useful tool for the study of some aspects of psychiatric disorders and their treatment. The four criteria for the evaluation of animal models of psychiatric disorders are as following : 1) similarity of inducing conditions 2) similarity of behavioral state 3) common underlying neurobiological mechanisms 4) reversal by clinically effective treatment techniques. Several animal models have been proposed for schizophrenia : phenylethylamine model, L-dopa model, hallucinogen model, cocaine model, amphetamine model, phencyclidine model, noradrenergic reward system lesion model, reticular stimulation model, social isolation model, conditioned avoidance reaction, catalepsy test, paw test, self-stimulation paradigms, latent inhibition paradigms, blocking paradigms, prepulse inhibition of the startle reflex, rodent interaction, social behavior in monkeys, hippocampal damage, high ambient pressure, and models using selective breeding. Among them, animals with bilateral lesion of the hippocampus may provide an adequate animal model for several symptoms of schizophrenia, and ketamine model can reproduce negative symptoms and cognitive deficits as well as positive symptoms of schizophrenia. In conclusion, no model of schizophrenia is entirely representative of the disease, and findings gleaned from model systems must be cautiously interpreted. Furthermore, the process of developing and validating animal models must work in concert with the process to identify reliable measures of human phenomenology.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.104-109
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• 2010

Purpose: $[^{18}F]$Fallypride plays an effective radiotracer for the study of dopamine $D_2/D_3$ receptor occupancy, neuropsychiatric disorders and aging in humans. This tracer has the potential for clinical use, but automated labeling efficiency showed low radiochemical yields about 5~20% with relatively long labelling time of fluorine-18. In present study, we describe an improved automatic synthesis of [$^{18}F$]Fallypride using different base concentration for routine clinical use. Materials and Methods: Fully automated synthetic process of [$^{18}F$]Fallypride was perform using the TracerLab $FX_{FN}$ synthesizer under various labeling conditions and tosyl-fallypride was used as a precursor. [$^{18}F$]Fluoride was extracted with various concentration of $K_{2.2.2.}/K_2CO_3$ from $^{18}O$-enriched water trapped on the ion exchange cartridge. After azeotropic drying, the labeling reaction proceeded in $CH_3CN$ at $100^{\circ}C$ for 10 or 30 min. The reaction mixture was purified by reverse phase HPLC and collected organic solution was exchanged by tc-18 Sep-Pak for the clinically available solution. Results: The optimal labeling condition of [$^{18}F$]Fallypride in the automatic production was that 2 mg of tosyl-fallypride in acetonitrile (1 mL) was incubated at $100^{\circ}C$ for 10 min with $K_{2.2.2.}/K_2CO_3$ (11/0.8 mg). [$^{18}F$]Fallypride was obtained with high radiochemical yield about $66{\pm}1.4%$ (decay-corrected, n=28) within $51{\pm}1.2$ min including HPLC purification and solid-phase purification for the final formulation. Conclusion: [$^{18}F$]Fallypride was prepared with a significantly improved radiochemical yield with high specific activity and shorten synthetic time. In addition, this automated procedure provides the high reproducibility with no synthesis failures (n=28).

• The Korean Journal of Nuclear Medicine
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• v.33 no.6
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• pp.527-536
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• 1999

Purpose: Radiotracers that bind to the central benzodiazepine receptor are useful for the investigation of various neurological and psychiatric diseases. [C-11]Flumazenil, a benzodiazepine antagonist, is the most widely used radioligand for central benzodiazepine receptor imaging by PET. We synthesized 3-(2-[F-18]fluoro)flumazenil, a new fluorine-18 ($t_{1/2}$= 110 min) labeled analogue of benzodiazepine receptor imaging agent, and evaluated in vivo for biodistribution in mice. Materials and Methods: Flumazenil (Ro 15-1788) was synthesized by a modification of the reported method. Precursor of 3-(2-[F-18]fluoro)flumazenil, the tosylated flumazenil derivative was prepared by the tosylation of the ethyl ester by ditosylethane. [F-18] labeling of tosyl substitued flumazenil precursor was performed by adding F-18 ion at $85^{\circ}C$ in the hot ceil for 20 min. The reaction mixture was trapped by C18 cartridge, washed with 10% ethanol, and eluted by 40% ethanol. Bidistribution in mice was determined after intravenous injection. Results: The total chemical yield of tosylated flumazenil derivative was ${\sim}40%$. The efficiency of labeling 3-(2-[F-18]fluoro)flumazenil was 66% with a total synthesis time of 50 min. Brain uptakes of 3-(2-[F-18]fluoro)flumazenil at 10, 30, 60 min after injection, were $2.5{\pm}0.37,\;2.2{\pm}0.26,\;2.1{\pm}0.11$ and blood activities were $3.7{\pm}0.43,\;3.3{\pm}0.07,\;3.3{\pm}0.09%ID/g$, respectively. Conclusion: We synthesized a tosylated flumazenil derivative which was successfully labeled with no-carrier-added F-18 by nucleophilic substitution.

• Korean Journal of Cognitive Science
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• v.27 no.2
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• pp.159-219
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• 2016

Mathematical ability is important for academic achievement and technological renovations in the STEM disciplines. This study concentrated on the relationship between neural basis of mathematical cognition and its mechanisms. These cognitive functions include domain specific abilities such as numerical skills and visuospatial abilities, as well as domain general abilities which include language, long term memory, and working memory capacity. Individuals can perform higher cognitive functions such as abstract thinking and reasoning based on these basic cognitive functions. The next topic covered in this study is about individual differences in mathematical abilities. Neural efficiency theory was incorporated in this study to view mathematical talent. According to the theory, a person with mathematical talent uses his or her brain more efficiently than the effortful endeavour of the average human being. Mathematically gifted students show different brain activities when compared to average students. Interhemispheric and intrahemispheric connectivities are enhanced in those students, particularly in the right brain along fronto-parietal longitudinal fasciculus. The third topic deals with growth and development in mathematical capacity. As individuals mature, practice mathematical skills, and gain knowledge, such changes are reflected in cortical activation, which include changes in the activation level, redistribution, and reorganization in the supporting cortex. Among these, reorganization can be related to neural plasticity. Neural plasticity was observed in professional mathematicians and children with mathematical learning disabilities. Last topic is about mathematical creativity viewed from Neural Darwinism. When the brain is faced with a novel problem, it needs to collect all of the necessary concepts(knowledge) from long term memory, make multitudes of connections, and test which ones have the highest probability in helping solve the unusual problem. Having followed the above brain modifying steps, once the brain finally finds the correct response to the novel problem, the final response comes as a form of inspiration. For a novice, the first step of acquisition of knowledge structure is the most important. However, as expertise increases, the latter two stages of making connections and selection become more important.