• Investigative Magnetic Resonance Imaging
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• v.21 no.2
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• pp.102-105
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• 2017

In adolescents, sleep deprivation problem is getting worse, and increased caffeine consumption is considered to relieve the stress caused by sleep deprivation and academic burden. In this study, immediate neurologic effects of caffeine intake on adolescents were evaluated in three high school students using the ${\gamma}-aminobutyric$ acid (GABA)/creatine ratio on magnetic resonance spectroscopy (MRS). MEGA-PRESS MRS and TE 135 ms single voxel MRS were performed in the anterior cingulate cortex before and after drinking a cup of coffee, which contained 104 mg of caffeine. GABA and creatine were measured on LCModel 6.3, respectively. In all three students, GABA/creatine ratios were decreased after caffeine intake. The GABA/creatine ratios obtained before caffeine intake were decreased after caffeine intake in all the three adolescents. In this preliminary study, caffeine intake caused an immediate decrease in the GABA/creatine ratio in the brain and it may be related to the neurologic effects of caffeine on an adolescent's brain.

• Investigative Magnetic Resonance Imaging
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• v.23 no.4
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• pp.390-394
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• 2019

Hemosiderosis is characterized by the deposition of excess iron in body tissues. The choroid plexus is an important part of the central nervous system that can be the primary site of iron overload. T2*-weighted gradient echo (GRE) sequence provides high sensitivity for demonstrating cerebral microhemorrhagic foci and iron deposition. In the present study, we describe the case of a 15-year-old boy with acute lymphoblastic leukemia, in whom repeated transfusion led to iron accumulation in the brain. GRE sequence effectively demonstrated hemosiderin deposition in the choroid plexus.

• Journal of the Korean Magnetic Resonance Society
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• v.13 no.2
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• pp.64-83
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• 2009

The purpose of this study was to evaluate the usefulness of in vivo 3T $^1H$ MRS with short TE for prescreening various brain diseases. Together with ten normal volunteers, 12 brain tumor patients(2 lymphomas, 5 malignant gliomas) and 5(benign meningiomas) and 10 brain ischemic disease patients(6 acute and 4 subacute infarctions) participated. Lymphomas showed increased intensities of Cho and Lac. Likewise, gliomas showed increased Cho and Lac, but with decreased NAA and ${\beta}\;{\gamma}$-Glx; in higher grade of gliomas, Lac, Cho, mI and Lip predominantly increased with decrease of NAA. Benign meningiomas showed increased Cho, Lac and ${\beta}\;{\gamma}$-Glx; with decreased of NAA. The alanine peak at 1.47 ppm is a neuronal marker for meningiomas. Infarctions showed increased Lac and Lip and decreased NAA, ${\alpha}$-Glx and ${\beta}\;{\gamma}$-Glx where Lac increased with decreased of ${\alpha}$-Glx in acute, and Cho, Lac and Lip increased with decrease of NAA in subacute. Elevated Lac and decreased NAA levels were more aggravated in subacute. Clinical application of the $^1H$ MRS with short TE at 3T is able to povide valuable spectral information for prescreening various brain diseases by monitoring the changes of disease-specific cerebral metabolite concentrations in vivo, and consequently, it can be applicable to assessment of differential diagnosis and malignancy as well.

• Journal of Biomedical Engineering Research
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• v.31 no.5
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• pp.412-416
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• 2010

In this study, we measured the chemical shift change of metabolite peaks in the brain-metabolite phantom according to the temperature variation using nuclear magnetic resonance(NMR). The temperature range in NMR system was controled from 25 to 80 (5 step) by internal temperature controller. Temperature coefficients of each metabolite peaks were also calculated from the measured chemical shift depending on the temperature. The chemical shift changes depending on temperature were validated by linear regression method for each metabolite peaks. The temperature coefficients of $_{tot}Cr$, Cho, Cr, NAA, and Lac were 0.0086, 0.0088, 0.0091, 0.0089, and 0.0088ppm/$^{\circ}C$, respectively. This study shows that chemical shift change of brain metabolite and temperature variation have linear relationship each other. This also makes authors believe that brain temperature measurement is possible using MR spectroscopic imaging technique.

• Dementia and Neurocognitive Disorders
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• v.16 no.2
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• pp.48-53
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• 2017

Background and Purpose Torrance Tests of Creative Thinking (TTCT) is a well-known and commonly used measure of creativity. However, the TTCT-induced creative hemodynamic brain activity is rarely revealed. The purpose of this study is to elucidate the neural correlates of creative thinking in the setting of a modified version of the figural TTCT adapted for an functional magnetic resonance imaging (fMRI) experiment. Methods We designed a blocked fMRI experiment. Twenty-five participants (11 males, 14 females, mean age $19.9{\pm}1.8$) were asked to complete the partially presented line drawing of the figural TTCT (creative drawing imagery; creative). As a control condition, subjects were asked to keep tracking the line on the screen (line tracking; control). Results Compared to the control condition, creative condition revealed greater activation in the distributed and bilateral brain regions including the left anterior cingulate, bilateral frontal, parietal, temporal and occipital regions as shown in the previous creativity studies. Conclusions The present revealed the neural basis underlying the figural TTCT using fMRI, providing an evidence of brain areas encompassing the figural TTCT. Considering the significance of a creativity test for dementia patients, the neural correlates of TTCT elucidated by this study may be valuable to evaluate the brain function of patients in the clinical field.

• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.10-26
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• 2019

Magnetic resonance-guided focused ultrasound (MRgFUS) is an emerging new technology with considerable potential to treat various neurological diseases. With refinement of ultrasound transducer technology and integration with magnetic resonance imaging guidance, transcranial sonication of precise cerebral targets has become a therapeutic option. Intensity is a key determinant of ultrasound effects. High-intensity focused ultrasound can produce targeted lesions via thermal ablation of tissue. MRgFUS-mediated stereotactic ablation is non-invasive, incision-free, and confers immediate therapeutic effects. Since the US Food and Drug Administration approval of MRgFUS in 2016 for unilateral thalamotomy in medication-refractory essential tremor, studies on novel indications such as Parkinson's disease, psychiatric disease, and brain tumors are underway. MRgFUS is also used in the context of blood-brain barrier (BBB) opening at low intensities, in combination with intravenously-administered microbubbles. Preclinical studies show that MRgFUS-mediated BBB opening safely enhances the delivery of targeted chemotherapeutic agents to the brain and improves tumor control as well as survival. In addition, BBB opening has been shown to activate the innate immune system in animal models of Alzheimer's disease. Amyloid plaque clearance and promotion of neurogenesis in these studies suggest that MRgFUS-mediated BBB opening may be a new paradigm for neurodegenerative disease treatment in the future. Here, we review the current status of preclinical and clinical trials of MRgFUS-mediated thermal ablation and BBB opening, described their mechanisms of action, and discuss future prospects.

• Journal of Veterinary Clinics
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• v.38 no.2
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• pp.89-93
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• 2021

2-Month-old, three related Perro de Presa Canario dogs were evaluated for similar neurological symptoms like circling, head pressing, depressed mental status, hypermetria, and vocalization. On magnetic resonance imaging (MRI) of the brain, there were large, bilaterally symmetrical lesions with involvement of thalamus, and brainstem that were T2- and FLAIR-hyperintense and T1-iso/hypointense. There was no inclusion of cerebellum. Single-voxel spectroscopy acquisition was located in the thalamus where abnormalities were found in MR images. The results of magnetic resonance spectroscopy (MRS) showed markedly decreased N-acetylaspartic acid value. Euthanasia was performed and lesions consistent with the canine spongy degeneration. Alteration in metabolites in the brain can be determined by MRS, which helps in diagnosing degeneration/leukodystrophy of the central nervous system in dogs.

• Investigative Magnetic Resonance Imaging
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• v.10 no.1
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• pp.26-31
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• 2006

Purpose : To evaluate the effect of global scaling analysis on brain activation for sensory and motor functional MR imaging study. Materials and methods : Four normal subjects without abnormal neurological history were included. Arm extension-flexion movement was used for motor function and 1KHz pure tone stimulation was used for auditory function. Functional magnetic resonance imaging was performed at 3T MRI (GE, Milwaukee, USA) using BOLD-EPI technique and SPM2 was employed for data analysis. On data analysis, the brain activation images were obtained with and without global scaling by fixing other parameters such as motion correction and realignment. Results : The difference in brain activation between no scaling and global scaling was not large in case of right upper extremity movement (p<0.000001). For auditory test, brain activation with global scaling showed larger activation than that of without global scaling (p<0.05). Conclusion : A caution must be taken into account when analyzing functional imaging data with global scaling especially for functional study of small local BOLD signal change.

• Journal of Veterinary Clinics
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• v.35 no.5
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• pp.178-183
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• 2018

The object of this study was to compare magnetic resonance imaging (MRI) findings and neurological signs in canine brain diseases. Brain diseases can cause severe neurological deficits and may be life-threatening. The antemortem diagnosis of the brain diseases is difficult for the clinician, since definitive diagnosis is based upon histopathological confirmation. Brain diseases are often associated with specific clinical signs, signalment, progression, and location. Accurate lesion localization through neurological examination and MRI findings is helpful for developing a differential diagnosis. A retrospective study was performed to compare the neurological examination of dogs with suspected brain disease to the MRI findings. Based on this study, neurological examination is a reliable way to localize most brain lesions. Postural reaction deficits do not provide sufficient information to localize lesions. Additionally, not all brain lesions present clinical signs and inflammatory lesions may cause no detectable abnormalities on MRI. Therefore, in clinical practice, a combination of neurological examination and MRI findings recommended for accurate brain lesion localization.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2004.11a
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• pp.18-18
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• 2004