• Investigative Magnetic Resonance Imaging
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• v.26 no.1
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• pp.10-19
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• 2022

Purpose: To evaluate whether the added value of contrast leakage information from dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) is a better prognostic imaging biomarker than the cerebral blood volume (CBV) value in distinguishing true progression from pseudoprogression in glioblastoma patients. Materials and Methods: Forty-nine glioblastoma patients who had undergone MRI after concurrent chemoradiotherapy with temozolomide were enrolled in this retrospective study. Twenty features were extracted from the normalized relative CBV (nCBV) and extraction fraction (EF) map of the contrast-enhancing region in each patient. After univariable analysis, we used multivariable stepwise logistic regression analysis to identify significant predictors for differentiating between pseudoprogression and true progression. Receiver operating characteristic (ROC) analysis was employed to determine the best cutoff values for the nCBV and EF features. Finally, leave-one-out cross-validation was used to validate the best predictor in differentiating between true progression and pseudoprogression. Results: Multivariable stepwise logistic regression analysis showed that MGMT (O⁶-methylguanine-DNA methyltransferase) and EF max were independent differentiating variables (P = 0.004 and P = 0.02, respectively). ROC analysis yielded the best cutoff value of 95.75 for the EF max value for differentiating the two groups (sensitivity, 61%; specificity, 84.6%; AUC, 0.681 ± 0.08; 95% CI, 0.524-0.837; P = 0.03). In the leave-one-out cross-validation of the EF max value, the cross-validated values for predicting true progression and pseudoprogression accuracies were 69.4% and 71.4%, respectively. Conclusion: We demonstrated that contrast leakage information parameter from DSC MRI showed significance in differentiating true progression from pseudoprogression in glioblastoma patients.

• The Korean Journal of Nuclear Medicine
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• v.32 no.5
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• pp.397-402
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• 1998

Purpose: The purpose of this study was to evaluate the phenomenon of diaschisis in the cerebellum and cerebral cortex in patients with pure basal ganglia hemorrhage using cerebral blood flow SPECT. Materials and Methods: Twelve patients with pure basal ganglia hemorrhage were studied with Tc-99m ECD brain SPECT. Asymmetric index (AI) was calculated in the cerebellum and cerebral cortical regions as |$C_R-C_L$/$(C_R-C_L){\times}200$, where $C_R$and $C_L$ are the mean reconstructed counts for the right and left ROIs, respectively. Hypoperfusion was considered to be present when AI was greater than mean +2 SD of 20 control subjects. Results: Mean AI of the cerebellum and cerebral cortical regions in patients with pure basal ganglia hemorrhage was significantly higher than normal controls (p<0.05): Cerebellum ($18.68{\pm}8.94$ vs $4.35{\pm}0.94$, $mean{\pm}SD$), thalamus ($31.91{\pm}10.61$ vs $2.57{\pm}1.45$), basal ganglia ($35.94{\pm}16.15$ vs $4.34{\pm}2.08$), parietal ($18.94{\pm}10.69$ vs $3.24{\pm}0.87$), frontal ($13.60{\pm}10.5$ vs $4.02{\pm}2.04$) and temporal cortex ($15.92{\pm}11.95$ vs $5.13{\pm}1.69$). Ten of the 12 patients had significant hypoperfusion in the contralateral cerebellum. Hypoperfusion was also shown in the ipsilateral thalamus (n=12), ipsilateral parietal (n=12), frontal (n=6) and temporal cortex (n=10). Conclusion: Crossed cerebellar diaschisis (CCD) and cortical diaschisis may frequently occur in patients with pure basal ganglia hemorrhage, suggesting that CCD can develop without the interruption of corticopontocerebellar pathway.

• Radiation Oncology Journal
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• v.21 no.1
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• pp.1-9
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• 2003

Purpose : The purpose of this study was to analyze the effect of a Linear accelerator based Photon Knife Radiosurgery System developed by the staff of Keimyung University Dongsan Medical Center for the treatment of cerebral arterlovenous malformation Material and Methods : Between December 1993 and October 2000, 30 patients with cerebral arteriovenous malformation (AVM) were treated with the Linac based Photon knife Radlosurgery System In the Department of Therapeutlc Radiology at Keimyung University Dongsan Medical Center. The median age was 34, ranging from 7 to 63 years, with a 2 : 1 male to female ratio. The locations of the AVM nidi were the frontal lobe (motor cortex), parletal lobe, and the thalamus, In that order. The diameters of the AVM nidi ranged 1.2 to 5.5 cm with a mean on 2.9 cm, and target volumes of between 0.5 and 20.5 cc, with a mean of 5.8 cc. The majority of patients received radiation doses of between 1,500 and 2,500 cGy, w14h a mean of 2,000 cGy, at 80% the isodose line. Twenty-five patients were treated with one isocenter, 4 with two, and 1 with four. The follow-up radiological evaluations were peformed with cranial computed tomogram (CT) or MRI between 6 month and one year interval, and if the AVM nidus had completely disappeared in the CT or MRI, we confirmed thls was a complete obliteration, with a cerebral or magnetic resonance angiogram (MRA). The median iollow-up period was 39 months with a range of 10 to 103 months. Results : Twenty patients were radloiogicaiiy followed up ior over 20 months, with complete obliteration observed in 14 (70%). According to the maximal diameter, all four of the small AVM (<2 cm) completely obliterated, 8 of the 10 patients with a medium AVW (2~3 cm) showed a complete obliteration, and two showed partial obliteration. Among the patients with a large AVM (>3 cm), only one showed complete obliteration, and S showed partial obliteration, but 3 oT these underwent further radiosurgery 3 years later. One who followed up for 20 months fellowing further radiosurgery eventually showed complete obliteration. Ten patients with seizure symptoms had no recurrent seizure due to radiosurgery and medication. One of the eleven patients who suffered intracranlal bleeding developed further bleeding at 9 and 51 months fellowing the radiosurgery although complete obliteration was eventually observed and the patient was managed in hospital then recovered. No patient suffered severe complications fellowing the radiosurgery. Conclusion : The radiosurgery with Linac-based Photon knife radiosurgery system, developed by the staff at our hospital, is a safe and effective treatment for AVM patients having diameters or volumes of less than 3 cm or 10 cm$^{3}$, respectively, located In Inoperable areas or who refused neurosurgery. We suggest that staged AVM radiosurgery may initially be considered, if the AVM target volume is above 10 cm$^{3}$

• Journal of Haehwa Medicine
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• v.16 no.1
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• pp.199-206
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• 2007

Objective : The purpose of this study is to report treated case about patient with diplopia caused by stroke. Methods : The improvement of diplopia was observed as he was treated with acupuncture therapy and herb medicine named Bo-gan-san(保肝散). Results : Diplopia improved and disappeared gradually with acupuncture therapy and herb medicine named Bo-gan-san(保肝散). The patient was discharged with favorable recovery. Conclusion : In traditional Korean medicine, diplopia is caused by disorder of JungKi(精氣), intrusion of PoongSa(風邪) into Neoi(腦), and hollowness of Gan(肝), Shin(腎). Treating it is by expelling PoongSa(風邪) or strengthening Gan(肝), Shin(腎). The patient was diagnosed as cerebral infarction according to Brain MRI. Diplopia was improved after acupunctural therapy and intaking Bo-gan-san(保肝散), herbal prescription selected from DongYiBoGam(東醫寶鑑).

• 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.

• Journal of Korean Neurosurgical Society
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• v.49 no.6
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• pp.370-372
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• 2011

Dissection of the middle cerebral artery (MCA) is less frequent compared with dissection of the vertebrobasilar system or carotid artery. Recently, high-resolution cross sectional MR imaging (HRMRI) has emerged as a potential technique for atherosclerotic plaque imaging in MCA, We introduce the findings of HRMRI in a 56-year-old woman with traumatic MCA dissection, HRMRI showed an intimal flap and tapered pseudolumen with intra-luminal hemorrhage, We performed stent deployment about MCA dissection after failed medical treatment Three months later, there was no in-stent restenosis and no further neurological deficit were noted.

• Journal of Korean Neurosurgical Society
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• v.44 no.2
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• pp.95-97
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• 2008

The authors report an extremely rare case with intraventricular and subarachnoid fat developed after trauma to spine and soft tissue in a 54-year-old male. The initial computed tomography (CT) showed multiple low attenuation lesions, which were thought to be pneumocephalus. Cerebral magnetic resonance imaging (MRI) showed lesions with high signal intensity on T1-weighted magnetic resonance images and high signal intensity on T2-weighted images, indicating fat globules within the CSF. In this report, the clinical presentation, radiological findings, and a review of the literature are presented.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2006.06a
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• pp.61-65
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• 2006

본 연구는 한국어 어휘중의성 해결과정에 관련된 대뇌활동을 살펴보기 위하여 MEG(magnetoencephalography)를 이용한 실험을 실시하였다. 일차적으로 기존의 중의성 관련 fMRI 실험 결과들이 MEG를 이용한 신호원 국소화 결과와 유사한 패턴을 보이는지 확인하였고, 본 실험의 주요 목적인 중의성 관련 처리과정에 기저하는 하위 처리과정이 어떠한 기능적 처리 요소들로 분해될 수 있는 지에 대해서도 시간 해상도가 높은 MEG의 특성을 이용하여 관찰하였다. 분석 결과, 한국어 중의어 해소과정의 하위처리 과정은 어휘의미 접속이라는 기본적인 과정 비에, 이들의 의미분지를 유발하는 단서의 유무가 그 활성화 영역의 시간적인 패턴과 중의성 해결을 위한 지속시간에 영향을 미치는 것으로 확인되었다.

• Journal of Korean Neurosurgical Society
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• v.53 no.3
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• pp.183-186
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• 2013

Septic internal jugular vein-sigmoid sinus thrombosis (IJV-SST) associated with a malpositioned central venous catheter is a rare condition. It is potentially life-threatening and necessitates early diagnosis and rapid administration of appropriate medications. Unfortunately, it is difficult to diagnose due to vague clinical presentations. Several studies such as CT, MRI, and cerebral angiography should be performed and carefully examined to help make the diagnosis. We report a case of septic IJV-SST due to a malpositioned central venous catheter.

• Proceedings of the KSPS conference
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• 2003.10a
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• pp.75-78
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• 2003

The paper deals with experimental results which was performed to investigate the characteristics of Korean lexical processing and representation of morphemes involved in Korean noun and verb Eojeols. The investigation is also related with the 'English past tense debate' which deals with human mental computation. Experiments using fMRI methods, show that Korean noun Eojeols and both regular and irregular verb Eojeols show a similar activation pattern. Thus, the results indicate that the morphological processing in Korean noun and verb Eojeols are performed quite differently than the Indo-European morphological processing.