• Journal of the Korean Magnetic Resonance Society
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• v.5 no.1
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• pp.56-65
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• 2001

Localized in vivo proton magnetic resonance spectroscopy (MRS) was performed to evaluate metabolic alterations in the right and left frontal lobe before and after neuroleptic treatment of schizophrenic patients (n=24) and a group of healthy normal subjects (n=20). Proton metabolic ratios obtained from the 8㎤ yokels in the right and left frontal lobe were compared with the clinical assessment of PANSS for each subject. There was no significant difference in the metabolic ratios between the right and the left frontal lobes in either the schizophrenic group or the control group, indicating no laterality. Compared with those of the normal control group, NAA/Cr and (GABA+Glu)/Cr ratios of the schizophrenic patients showed significantly lower (p=0.023) and higher (p=0.005) value, respectively. The (GABA+Glu)/Cr ratio of the schizophrenic patients was generally decreased after neuroleptic treatment, while the NAA/Cr ratio was not changed. Significant correlation between the (GABA+Glu)/Cr ratio and the clinical symptom scores assessed by PANSS was established. The present study supports the “hypofrontality” hypothesis of schizophrenia on the basis of the altered metabolic ratios before and after neuroleptic treatment.

• Investigative Magnetic Resonance Imaging
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• v.19 no.2
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• pp.99-106
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• 2015

Purpose: To investigate factors influencing the evaluation of background parenchymal enhancement (BPE) at follow-up breast magnetic resonance imaging (MRI) after adjuvant endocrine therapy. Materials and Methods: One hundred twelve women with breast cancer and MRI of the contralateral unaffected breast before and after endocrine therapy were identified. Two readers in consensus performed blinded side-by-side comparison of BPE (minimal, mild, moderate, and marked) before and after therapy with categorical scales. Age, body mass index, menopausal status, treatment regimen (selective estrogen receptor modulator or aromatase inhibitor), chemotherapy, follow-up duration, BPE at baseline MRI, MRI field strength before and after therapy, and recurrence were analyzed for their influences on decreased BPE. Results: Younger age, premenopausal status, treatment with selective estrogen receptor modulator, MRI field strength, and moderate or marked baseline BPE were significantly associated with decreased BPE. In multivariate analysis, MRI field strength and baseline BPE showed a significant association. Conclusion: MRI field strength and baseline BPE before and after therapy .were associated with decreased BPE at post-therapy, follow-up MRI.

• Investigative Magnetic Resonance Imaging
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• v.25 no.3
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• pp.197-200
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• 2021

Ramsay Hunt syndrome (RHS) is a disease caused by varicella-zoster virus (VZV) infection that can be diagnosed through clinical symptoms with or without imaging evaluations. The typical features of RHS on imaging evaluation include signal changes and enhancement in the internal auditory canal (IAC) nerves, and the labyrinthine segment of cranial nerve VII (CN VII) and cranial nerve VIII (CN VIII). In some patients, inner ear structure (cochlear and vestibular apparatus) is involved in RHS. Neurologic complications, such as encephalitis and meningitis, are rare in RHS, but are known to occur. Therefore, magnetic resonance imaging (MRI) is necessary to detect both abnormal signal intensity in the IAC, CN VII, CN VIII, inner and ear structure, and CNS complications. We report an RHS patient with CN VII, VIII, and leptomeningeal enhancement within the cerebellar folia on 10-min delayed, contrast-enhanced (CE), three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging.

• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.26-36
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• 2018

Purpose: Children born with single ventricle physiology demonstrate poor growth rate and suffer from malnutrition, which lead to increased morbidity and mortality in this population. We assume that an anabolic steroid, oxandrolone, will promote growth in these infants by improving myocardial energy utilization. The purpose of this paper is to study the efficacy of oxandrolone on myocardial energy consumption in these infants. Materials and Methods: We modeled single ventricle physiology in a lamb by prenatally shunting the aorta to the pulmonary artery and then postnatally, we monitored cardiac energy utilization by quantitatively measuring the first order reaction rate constant, $k_f$ of the creatine-kinase reaction in the heart using magnetization transfer $^{31}P$ magnetic resonance spectroscopy, home built $^1H/^{31}P$ transmit/receive double tuned coil, and transmit/receive switch. We also performed cine MRI to study the structure and dynamic function of the myocardium and the left ventricular chamber. The spectroscopy data were processed using home-developed python software, while cine data were analyzed using Argus software. Results: We quantitatively measured both the first order reaction rate constant and ejection fraction in the control, shunted, and the oxandrolone-treated lambs. Both $k_f$ and ejection fraction were found to be more significantly reduced in the shunted lambs compared to the control lambs, and they are increased in oxandrolone-treated lambs. Conclusion: Some improvement was observed in both the first order reaction rate constant and ejection fraction for the lamb treated with oxandrolone in our preliminary study.

• Korean journal of food and cookery science
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• v.33 no.2
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• pp.148-154
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• 2017

Purpose: Frozen Korean traditional rice cakes (Sulgitteok and Garaetteok) were evaluated different conditions ($-20^{\circ}C$ and $-10^{\circ}C$) freezing (magnetic resonance quick freezing and air blast freezing) to study differences in quality characteristics. Methods: Experiments analyze Korean rice cakes for water content, water activity, color, textural properties, and sensory characteristics. Results: Moisture content showed high value at $-20^{\circ}C$ freezing regardless of freezing method. Water activity was higher at $-20^{\circ}C$ than $-10^{\circ}C$, and water activity higher magnetic resonance quick freezing than air blast freezing. The lightness values were higher $-20^{\circ}C$ freezing temperature compare to $-10^{\circ}C$ freezing temperature. Hardness and chewiness were the lowest $-20^{\circ}C$ magnetic resonance quick freezing. sensory evaluation both Sulgitteok and Garaetteok showed better overall acceptability at $-20^{\circ}C$ magnetic resonance quick freezing. Conclusion: Therefore, the $-20^{\circ}C$ magnetic resonance quick freezing method resulted in favorable textural properties and sensory characteristics.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.1
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• pp.29-38
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• 2018

In order to evaluate the performance of the floating wave power, which is an axisymmetric oscillating water column type, linearized free surface boundary condition considering the influence of PTO (power takeoff) was derived and a finite element numerical model was established. Numerical experiments were carried out by varying cylinder length, skirt length, and depth of water, which are design parameters that can change the resonance of water column in cylinder and heave resonance of the float, which is considered to affect the power generation efficiency. Finally, the basic data necessary for the optimum design of the power generation system were obtained. As a result, the efficiency of the power generation system is dominated by the heave motion resonance of the float rather than the water column resonance in the cylinder, and the resonance condition for the heave motion can be changed efficiently by attaching the skirt to the outside of the buoy.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.171-190
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• 1996

Quality evaluation of agricultural products has been a subject of interest to many researches for many years. As a results, several nondestructive techniques for quality evaluation of agricultural products have been developed. These methods are based on the detection of various physical properties that correlate well with certain quality factors of the products. This paper presents an overview of various quality evaluation techniques that are based on one of the following properties : density, firmness , vibration characteristic , X-ray and gamma ray transmission, optical reflectance and transmission , electrical properties, aromatic volatile emission, and nuclear magnetic resonance (NMR). The sophistication of nondestructive methods has evolved rapidly with modern technologies. The use of various modern image acquisition techniques, such as solid state TV camera, line-scan camera, X-ray scanning , ultrasonic scanning and NMR imaging, in conjunction with image-processing te hniques has provided new opportunities for researchers to develop many new and improved techniques for nondestructive quality evaluation of agricultural products.

• Korean Journal of Radiology
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• v.22 no.1
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• pp.23-40
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• 2021

In pancreatic cancer, imaging plays an essential role in surveillance, diagnosis, resectability evaluation, and treatment response evaluation. Pancreatic cancer surveillance in high-risk individuals has been attempted using endoscopic ultrasound (EUS) or magnetic resonance imaging (MRI). Imaging diagnosis and resectability evaluation are the most important factors influencing treatment decisions, where computed tomography (CT) is the preferred modality. EUS, MRI, and positron emission tomography play a complementary role to CT. Treatment response evaluation is of increasing clinical importance, especially in patients undergoing neoadjuvant therapy. This review aimed to comprehensively review the role of imaging in relation to the current treatment strategy for pancreatic cancer, including surveillance, diagnosis, evaluation of resectability and treatment response, and prediction of prognosis.

• Proceedings of the KSMRM Conference
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• 2004.09a
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• pp.41-42
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.149-150
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• 2004