• Nuclear Medicine and Molecular Imaging
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• 제43권3호
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• pp.179-195
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• 2009

Scince $^{201}$TI was introduced as a myocardial perfusion imaging agent in the early 1970s, scintigraphic evaluation of myocardial perfusion for the diagnosis of coronary artery disease is a valuable noninvasive diagnostic imaging modality. Stress radionuclide myocardial perfusion imaging is widely accepted to have high diagnostic and prognostic use in the assessment of patients with known or suspected coronary artery disease. With wise use of this nonivasive imaging technique, more patients are referred for stress perfusion imaging. Until now various protocols for stress testing and myocardial imaging were developed and used in worldwide. This article presented various protocols of stress testing and myocardial imaging for clinical use.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.100-100
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• 2003

In brain MR imaging, contrast-enhanced study is important in the detection and characterization of lesions. As a postcontrast brain MR imaging, conventional T1 weighted imaging has been usually used. Magnetization transfer imaging has been used to increase conspicuity of enhancing lesions. In addition, fat-suppression imaging can be used as in other parts of the body. Recently, FLAIR sequence has been reported to be useful in detecting subarachnoid, meningeal, and subdural abnormalities. In this exhibit, we demonstrate basic principles and typical appearances of various pulse sequences that can be used as a postcontrast brain MR imaging in children. Furthermore, we discuss imaging strategies to increase clinical usefulness of postcontrast brain MR imaging for specific abnormalities. The advantages and disadvantages of each pulse sequence are also discussed.

• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2009년도 추계학술대회
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• pp.240-240
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• 2009

• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2009년도 추계학술대회
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• pp.239-239
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• 2009

• 대한의용생체공학회:의공학회지
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• 제17권1호
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• pp.93-98
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• 1996

The purpose of this paper is to propose a new localized imaging method of reduced imaging time luting a locally-linear gradient. Since most fast MR(Magnetic Resonance) imaging methods need the whole $\kappa$-space(Spatial frequency space) data corresponding to the whole imaging area, there are limitstions in reducing the minimum imaging time. The imaging method proposed in this paper uses a specially-made gradient coil generating a local ramp-shape field and uniform field outside of the imaging areal Conventional imaging sequences can be used without any RF/gradient pulse sequence modifiestions except the change in the number of encoding steps and the field of view.

• Nuclear Medicine and Molecular Imaging
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• 제40권2호
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• pp.96-105
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• 2006

Molecular imaging has its root in nuclear medicine and gene therapy monitoring. Therefore, recent progress in the development of non-invasive imaging technologies, particularly nuclear medicine, should allow molecular imaging to play a major role in the field of gene therapy. These tools have recently been validated in gene therapy models for continuous quantitative monitoring of the location, magnitude, and time-variation of gene delivery and/or expression. This article reviews the use of radionuclide imaging technologies as they have been used in imaging gene delivery and gene expression for gene therapy applications. The studios published to date lend support that noninvasive imaging tools will help to accelerate pre-clinical model validation as well as allow for clinical monitoring of human gene therapy.

• Investigative Magnetic Resonance Imaging
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• 제23권1호
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• pp.1-16
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• 2019

Dynamic contrast enhanced (DCE) magnetic resonance (MR) imaging plays an important role in non-invasive detection and characterization of primary and metastatic lesions in the liver. Recently, efforts have been made to improve spatial and temporal resolution of DCE liver MRI for arterial phase imaging. Review of recent publications related to arterial phase imaging of the liver indicates that there exist primarily two approaches: breath-hold and free-breathing. For breath-hold imaging, acquiring multiple arterial phase images in a breath-hold is the preferred approach over conventional single-phase imaging. For free-breathing imaging, a combination of three-dimensional (3D) stack-of-stars golden-angle sampling and compressed sensing parallel imaging reconstruction is one of emerging techniques. Self-gating can be used to decrease respiratory motion artifact. This article introduces recent MRI technologies relevant to hepatic arterial phase imaging, including differential subsampling with Cartesian ordering (DISCO), golden-angle radial sparse parallel (GRASP), and X-D GRASP. This article also describes techniques related to dynamic 3D image reconstruction of the liver from golden-angle stack-of-stars data.

• Current Optics and Photonics
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• 제7권5호
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• pp.537-544
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• 2023

Differential phase contrast (DPC) microscopy, a central quantitative phase imaging (QPI) technique in cell biology, facilitates label-free, real-time monitoring of intrinsic optical phase variations in biological samples. The existing DPC imaging theory, while important for QPI, is grounded in paraxial diffraction theory. However, this theory lacks accuracy when applied to high numerical aperture (NA) systems that are vital for high-resolution cellular studies. To tackle this limitation, we have, for the first time, formulated a nonparaxial DPC imaging equation with a transmission cross-coefficient (TCC) for high NA DPC microscopy. Our theoretical framework incorporates the apodization of the high NA objective lens, nonparaxial light propagation, and the angular distribution of source intensity or detector sensitivity. Thus, our TCC model deviates significantly from traditional paraxial TCCs, influenced by both NA and the angular variation of illumination or detection. Our nonparaxial imaging theory could enhance phase retrieval accuracy in QPI based on high NA DPC imaging.

• IMMUNE NETWORK
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• 제12권6호
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• pp.223-229
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• 2012

Clinical and preclinical in vivo immune cell imaging approaches have been used to study immune cell proliferation, apoptosis and interaction at the microscopic (intra-vital imaging) and macroscopic (whole-body imaging) level by use of ex vivo or in vivo labeling method. A series of imaging techniques ranging from non-radiation based techniques such as optical imaging, MRI, and ultrasound to radiation based CT/nuclear imaging can be used for in vivo immune cell tracking. These imaging modalities highlight the intrinsic behavior of different immune cell populations in physiological context. Fluorescent, radioactive or paramagnetic probes can be used in direct labeling protocols to monitor the specific cell population. Reporter genes can also be used for genetic, indirect labeling protocols to track the fate of a given cell subpopulation in vivo. In this review, we summarized several methods dealing with dendritic cell, macrophage, and T lymphocyte specifically labeled for different macroscopic whole-body imaging techniques both for the study of their physiological function and in the context of immunotherapy to exploit imaging-derived information and immune-based treatments.

• 한국방사선학회논문지
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• 제6권5호
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• pp.409-414
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• 2012

본 연구는 나노 조영제를 이용하여 분자영상을 획득하고 이와 동일한 조건의 일반영상을 획득하여 두 영상을 DWT(Discrete Wavelet Transform)로 변환하여 분자영상과 일반영상간의 차이를 분석하였다. 현재까지의 분자영상 기술은 나노 조영제를 이용한 MR 영상과, PET를 이용한 분자영상 연구가 주류를 이루고 있다. MRI를 이용한 동일병변의 일반영상과 분자영상을 DWT로 분석한 결과 병변이 존재하는 블록에서는 병변이 있음을 예시하여 주는 고주파 특징값이 일반영상과 분자영상 모두 더 높게 나타나는 것을 알 수 있었다. 특히 고주파 영역의 특징추출값은 분자영상이 더 높게 나타남을 알 수 있었다.