• 한국임상수의학회지
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• 제16권1호
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• pp.75-79
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• 1999

Magnetic resonance imaging (MRI) is an imaging technique used to produce high quality images of the inside of the animal body. MRI is based on the principles of nuclear magnetic resonance (NMR) and started out as a tomographic imaging technique, that is it produced an image of the NMR signal in a thin slice through the animal body. The animal body is primarily fat and water, Fat and water have many hydrogen atoms. Hydrogen nuclei have an NMR signal. For these reasons magnetic resonance imaging primarily images the NMR signal from the hydrogen nuclei. Hydrogen protons, within the body align with the magnetic field. By applying short radio frequency (RF) pulses to a specific anatomical slice, the protons in the slice absorb energy at this resonant frequency causing them to spin perpendicular to the magnetic field. As the protons relax back into alignment with the magnetic field, a signal is received by an RF coil that acts as an antennae. This signal is processed by a computer to produce diagnostic images of the anatomical area of interest.

• 동의생리병리학회지
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• 제19권3호
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• pp.830-833
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• 2005

Intracranial lipomas are rare lesions, which are believed to be congenital malformations. They are usually asymptomatic incidental findings and localized in the midline. However, they may occasionally produce neurological symptoms such as seizure, headache, mental changes, paresis. Currently, diagnosis of intracranial lipomas is made on based of imaging modalities, particularly Magnetic resonance imaging(MRI). Because Lipomas are strongly adherent to the surroundings and typically enclose both vessels and nerves, Surgical approach is rarely indicated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.235-237
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• 1998

Gradient coil offers the spatial informations of sample or patient in Nuclear Magnetic Resonance Imaging(NMRI) and its gradient field linearity over the field of view(FOV) has many influence on the MR imaging. Accurate and good quality MR imaging can be acquired by the high gradient field linearity over the FOV. So it is an important part to design of gradient coil with good linearity in the wide imaging range. Usually, Z-directional gradient field is generated by using the Helmholtz type coil which is consisted of one-pair loop with anti-current path. It gets less about 40% linearity of the diameter spherical volume(DSV). In this study, we calculated optimized geometrical parameters of two-pair loop system to cancel odd terms up to $B_7$ included effectively. we also analyzed and compared the gradient field distribution and linearity of the common Helmholtz coil with them of the two-pair loop system.

• 대한방사선기술학회지:방사선기술과학
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• 제44권4호
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• pp.315-325
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• 2021

The purpose of this study is to investigate the changes in lipid proton (LP) composition according to the induced obese fatty liver and to use it as basic data for treatment and diagnosis of fatty liver in the future. The phantom study was conducted to identify differences between STEAM and PRESS Pulse sequences in LP concentration. A high-fat diet (60%) was administered to eight Sprague-Dawley rats to induce obesity and fatty liver disease. Baseline magnetic resonance imaging /spectroscopy data were obtained prior to the introduction of high-fat diet, and data acquisition experiments were performed after eight weeks using procedures identical to those used for baseline studies. The six lipid proton metabolites were calculated using LCModel software. The correlation between the fat percentage and each LP, revealed that the methylene protons at 1.3 ppm showed the highest positive correlation. The α-methylene protons to carboxyl and diallylic protons showed negative correlation with fat percentage. The methylene proton showed the highest increase in the LP; however, it constituted only 71.86% of the total LP concentration. The methylene proton plays a leading role in fat accumulation in liver parenchyma.

• 한국콘텐츠학회논문지
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• 제11권6호
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• pp.289-301
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• 2011

본 연구는 음악요법이 자기공명영상(MRI) 검사로 인한 불안정도와 검사시 불편감에 미치는 음악요법의 효과를 파악하고자 시도된 비동등성 대조군 사전-사후 실험설계의 유사실험이다. "음악요법을 받은 군은 음악요법을 받지 않는 군보다 검사 중 불안 점수가 낮을 것이다"는 음악요법 실시 후 실험군의 불안점수가 대조군의 불안점수와 비교하여 유의한 차이가 있어 채택되었다. "음악요법을 받은 군은 음악요법을 받지 않는 군보다 검사 후 활력징후가 낮을 것이다"는 수축기 혈압, 이완기혈압에 대한 가설은 기각되었지만, 맥박에서는 유의 한 차이가 나타나 부분적으로 채택 되었다. "음악요법을 받은군은 음악요법을 받지 않는 군보다 주간적 불편감이 낮을 것이다"는 두 집단간의 유의한 차이를 보였다. 한편 주관적인 불편감의 하부요인 중 긴장감 에서만 유의한 차이가 있었으며, 동통, 어지러움, 공포감에서는 유의한 차이가 없었다. 이상의 연구결과로 볼 때 음악요법은 자기공명영상(MRI) 검사중 환자의 상태불안을 감소시킬 수 있는 유용한 대체검사법이 될 수 있을 것이라고 생각된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제15권3호
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• pp.189-197
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• 1993

Tempormandibular Joint pain and dysfunction is a common and important clinical problem. With the recent advances in imaging technology, radiologists have made major contribution to the understanding of TMJ disease. The MRI has several advantages over the conventional imaging methods. It is possible to obtain surprisingly precise images of internal hard and soft tissues with MRI. It is not invasive without ionizing radiation. The abnormal disk position has been thought as the cause of TMJ internal derangement. But there are few methods to relate disk position to TMJ internal derangement quantatively. The object of our study is to determine the amount of anterior displacement fo articular disk in symptomatic patients related each symptoms. Using the method of Dr. Drace, we studied the 38 joints of 22 persons with susceptable TMJ internal derangement. 1. In determining the anterior displacement of TMJ articular disk, the junction between the posterior band and bilaminar zone was useful. 2. The mean anterior displacement of disk in reduction group and without reduction group were $51.0^{\circ}C$ and $81.1^{\circ}C$ respectively. The difference was significant. 3. In the mean anterior displacement of disk, the pain without clicking group showed $84.8^{\circ}C$ and the clicking and pain group $70.8^{\circ}C$, the clicking group respectively.