• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.423-424
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• 1999

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.172-173
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• 1999

• Investigative Magnetic Resonance Imaging
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• v.25 no.4
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• pp.218-228
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• 2021

Due to their high degree of freedom to transfer and acquire light, fiber optics can be used in the presence of strong magnetic fields. Hence, optical sensing and imaging based on fiber optics can be integrated with magnetic resonance imaging (MRI) diagnostic systems to acquire valuable information on biological tissues and organs based on a magnetic field. In this article, we explored the combination of MRI and optical sensing/imaging techniques by classifying them into the following topics: 1) functional near-infrared spectroscopy with functional MRI for brain studies and brain disease diagnoses, 2) integration of fiber-optic molecular imaging and optogenetic stimulation with MRI, and 3) optical therapeutic applications with an MRI guidance system. Through these investigations, we believe that a combination of MRI and optical sensing/imaging techniques can be employed as both research methods for multidisciplinary studies and clinical diagnostic/therapeutic devices.

• Investigative Magnetic Resonance Imaging
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• v.25 no.2
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• pp.59-75
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• 2021

The fornix is the major white-matter outflow tract from the hippocampus; it has a significant role in cognitive function. It is readily imaged via magnetic resonance imaging; its main parts are the crura, commissure, body, and columns. In this pictorial essay, we describe and illustrate the functional and imaging anatomy of the fornix and limbic system, as well as various disease entities involving the fornix.

• Investigative Magnetic Resonance Imaging
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• v.22 no.3
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• pp.187-193
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• 2018

Sweet's syndrome also known as acute neutrophilic dermatosis is a multisystem inflammatory disorder characterized by fever, malaise, leukocytosis, and skin lesions. Sweet's syndrome affects multiple organs though only rarely does it affect the central nervous system (CNS) when it does it is called Neuro-Sweet disease (NSD). We report on a case study of a biopsy-proven NSD in a 50 year old man. Serial magnetic resonance imaging (MRI) showed repeated CNS involvement of Sweet's syndrome after a respiratory tract infection preceded it. On the MRI, T2 hyperintense lesions occurred at multiple sites and disappeared after steroid therapy.

• Communications of the Korean Mathematical Society
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• v.16 no.3
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• pp.519-541
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• 2001

Magnetic Resonance Electrical Impedance Tomography(MREIT) is a new medical imaging technique for the cross-sectional conductivity distribution of a human body using both EIT(Electrical Impedance Tomography) and MRI(Magnetic Resonance Imaging) system. MREIT system was designed to enhance EIT imaging system which has inherent low sensitivity of boundary measurements to any changes of internal tissue conductivity values. MREIT utilizes a recent CDI (Current Density Imaging) technique of measuring the internal current density by means of MRI technique. In this paper, a mathematical modeling for MREIT and image reconstruction method called the alternating J-substitution algorithm are presented. Computer simulations show that the alternating J-substitution algorithm provides accurate high-resolution conductivity images.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.597-599
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• 1998

The clinical acceptance of magnetic resonance imaging(MRI) system has been more rapid than that of the other medical image diagnosis system(X-ray, CT, etc) with the advantage of nonhazardous nature, high resolution capability, potential for chemically specified imaging. MRI system is composed of super conducting magnet, gradient fields, rf transceiver, system controller and imaging software technology. In this paper, introducing the principle of magnetic resonance imaging, it proposes the implementation of PC-based MRI system.

• Investigative Magnetic Resonance Imaging
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• v.25 no.4
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• pp.229-251
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• 2021

Arteriosclerosis is the leading cause of stroke, with a fatality rate surpassing that of ischemic heart disease. High-resolution vessel wall magnetic resonance imaging is generally recognized as a non-invasive and panoramic method for the evaluation of arterial plaque; however, this method requires improved signal-to-noise ratio and scanning speed. Recent advances in high-density head and neck coil arrays are characterized by broad coverage, multiple channels, and closefitting designs. This review analyzes fast magnetic resonance imaging from the perspective of accelerated algorithms for vessel wall imaging and demonstrates the need for effective algorithms for signal acquisition using advanced radiofrequency system. We summarize different phased-array structures under various experimental objectives and equipment conditions, introduce current research results, and propose prospective research studies in the future.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.32-41
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• 1997

• Investigative Magnetic Resonance Imaging
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• v.24 no.3
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• pp.95-122
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• 2020

In this article, we evaluated the performance of radiofrequency (RF) coils in terms of the signal-to-noise ratio (S/N) and homogeneity of magnetic resonance images when used for ultrahigh-frequency (UHF) 7T magnetic resonance imaging (MRI). High-quality MRI can be obtained when these two basic requirements are met. However, because of the dielectric effect, 7T magnetic resonance imaging still produces essentially a non-uniform magnetic flux (|B₁|) density distribution. In general, heterogeneous and homogeneous RF coils may be designed using electromagnetic (EM) modeling. Heterogeneous coils, which are surface coils, are used in consideration of scalability in the |B₁| region with a high S/N as multichannel loop coils rather than selecting a single loop. Loop coils are considered state of the art for their simplicity yet effective |B₁|-field distribution and intensity. In addition, combining multiple loop coils allows phase arrays (PA). PA coils have gained great interest for use in receiving signals because of parallel imaging (PI) techniques, such as sensitivity encoding (SENSE) and generalized autocalibrating partial parallel acquisition (GRAPPA), which drastically reduce the acquisition time. With the introduction of a parallel transmit coil (pTx) system, a form of transceiver loop arrays has also been proposed. In this article, we discussed the applications and proposed designs of loop coils. RF homogeneous coils for volume imaging include Alderman-Grant resonators, birdcage coils, saddle coils, traveling wave coils, transmission line arrays, composite right-/left-handed arrays, and fusion coils. In this article, we also discussed the basic operation, design, and applications of these coils.