• Title, Summary, Keyword: in-vivo 영상

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In Vivo Visualization of Flow in Xylem Vessels of a Bamboo Using X-ray Micro-imaging Technique (X-ray 미세영상기법을 이용한 식물 목질부 내부 수액 유동의 계측)

  • Kim, Yang-Min;Lee, Sang-Joon
    • Proceedings of the KSME Conference
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    • pp.1693-1696
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    • 2004
  • Synchrotron X-ray micro-imaging technique was employed to monitor non-invasively the refilling process of water inside the xylem vessels in bamboo leaves. The consecutive phase-contrast X-ray images clearly show both plant anatomy and the transport of water inside the xylem vessels. Traces of water-rise, vapor bubbles and variations of contact angle between the water front and the xylem wall were measured in real time. During the refilling process, air bubbles are removed when the rising water front halts at a vessel end for a while. Subsequently, it starts rising again at a higher velocity than the normal refilling speed. Repeated cavitation seems to deteriorate the refilling ability in xylem vessels. In dark environment, the water refilling process in xylem vessels is facilitated more effectively than in bright illuminated conditions. Finally, X-ray micro-imaging was famed to be a powerful, high resolution, real time imaging tool to investigate the water refilling process in xylem vessels.

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Reduction of Seam Line Using an FIR Filter in Spatially Compounded Ultrasonic Diagnostic Images (공간합성된 초음파 의료영상에서 FIR 필터를 이용한 심라인 감소방법)

  • Choi, Myoung Hwan
    • Journal of Industrial Technology
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    • v.28 no.B
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    • pp.129-133
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    • 2008
  • A method to reduce seam line artifact in spatial compounding of ultrasonic images is presented. Spatial compounding is a speckle reducing imaging technique in which a number of ultrasound images of a given target that have been obtained from multiple view angles are combined into a single compounded image by combining the data received from each data point in the compounded image. Since different view angle results in different view area, and the images of different view arms are combined into an image, the compounded image consists of regions with different signal to noise ratio, and the boundary lines between these regions are visible as seam lines in the compounded images. In this paper, we present an algorithm that reduces the visibility of this seam line in the spatially compounded images. Design procedure for a FIH filter is described and the results of applying the filter to in-vivo ultrasonic images are analyzed.

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Frequency-domain Diffuse Optical Tomography System Adopting Lock-in Amplifier (Lock-in 증폭기를 채용한 주파수영역 확산 광단층촬영 시스템)

  • Jun, Young-Sik;Baek, Woon-Sik
    • Korean Journal of Optics and Photonics
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    • v.22 no.3
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    • pp.134-140
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    • 2011
  • In this paper, we developed a frequency-domain diffuse optical tomography(DOT) system for non-invasively imaging in vivo. The system uses near-infrared(NIR) light sources and detectors for which the photon propagation in human tissue is dominated by scattering rather than by absorption. We present the experimental reconstruction images of absorption and scattering coefficients using a liquid tissue phantom, and we obtain the location and shape of an anomaly which has different optical properties than the phantom.

Detection of Intracellular Free Metal Ions with Molecular Two-Photon Sensors (이광자 분자센서를 이용한 생체 내 금속이온 검출)

  • Kim, Hwan-Myung
    • Clean Technology
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    • v.17 no.3
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    • pp.231-237
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    • 2011
  • Two-photon microscopy (TPM) is attracting much attention in biological imaging due to the capability of imaging deep inside the living tissues for a long period of time. For maximum utilization of TPM, it is essential to develop efficient twophoton sensors. Regarding this, many research groups are developing two-photon sensors for specific applications. In this review, we summarize recent results on selected examples of two-photon sensors for intracellular free metal ions in the live cells and tissues to provide a guideline for various imaging applications.

Study in vivo metabolism using nuclear medical examination of the dose rate reduction (체내대사를 이용한 핵의학적 검사의 선량률 저감에 관한 연구)

  • Kang, Yong-Gil;Na, Soo-Kyung;Hong, Jin-Woong;Lee, Gui-Won;Kim, Nak-Sang
    • Korean Journal of Digital Imaging in Medicine
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    • v.14 no.2
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    • pp.75-81
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    • 2012
  • The purpose of this study was administered to the body for examination and treatment, high-energy radioactive isotope(F-18, I-131) in vitro discharge experiments. Increasing exposed dose of radiation to health professionals is caused by the increase of PET/CT use and a radioactive isotope. Therefore, the high-energy isotope F-18 and I-131 after administration about using Metabolite excretion was studied. As a results of this study, patients had plenty of fluids for testing and treatment alone administered radiopharmaceuticals can be more than twice as fast excretion induced emissions. Also was able to get a better image space to reduce the dose rate.

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Three-dimensional Chemical Shift Imaging with PRESS Excitation and Spiral Readouts (점구분 분광술 여기 방식과 나선형 판독경사를 이용한 삼차원 화학적 변위 영상법의 개발)

  • Kim, Dong-Hyun
    • Investigative Magnetic Resonance Imaging
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    • v.12 no.1
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    • pp.27-32
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    • 2008
  • Purpose : We developed a 3D CSI (chemical shift imaging) sequence that uses the PRESS (point resolved spectroscopy) excitation scheme and spiral-based readout gradients. Materials and Methods : We implemented constant-density spirals ($32{\times}32$ matrix, $24{\times}24\;cm$ FOV) which use analytic equations to enable real-time prescription on the scanner. In-vivo data from the brain were collected and reconstructed using the gridding algorithm. Results : Data illustrate that with our imaging sequence, the benefits of the PRESS technique, which include elimination of lipid artifacts, remain intact while flexible scan time versus resolution tradeoffs can be achieved using the constant-density spirals. Volumetric high resolution 3D CSI covering 5760 cm3 could be obtained in 12.5 minutes. Conclusion : Spiral-based readout gradients offer a flexible tradeoff between scan time versus resolution. By combining this feature with PRESS based excitation, efficient methods of volumetric spectroscopic imaging can be accomplished by obtaining whole brain coverage while eliminating lipid contamination.

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Generation Method of Spatiotemporal Image for Detecting Leukocyte Motions in a Microvessel (미소혈관내 백혈구 운동검출을 위한 시공간 영상 생성법)

  • Kim, Eung Kyeu
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.9
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    • pp.99-109
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    • 2016
  • This paper presents a method for generating spatiotemporal images to detect the leukocyte motions in a microvessel. By using the constraint that the leukocytes move along the contour line of a blood vessel wall, the method detects leukocyte motions and then generates spatiotemporal images. the translational motion by a movement in vivo is removed first by the template matching method. Next, a blood vessel region is detected by the automatic threshold selection method to binarize the temporal variance image, then a blood vessel wall's contour is expressed by B-spline function. With the detected blood vessel wall's contour as an initial curve, the plasma layer of the best accurate position is determined to be the spatial axis by snake. Finally, the spatiotemporal images are generated. The experimental results show the spatiotemporal images are generated effectively through the comparison of each step of three image sequences.

Comparisons of functional brain mappings in sensory and affective aspects following taste stimulation (미각자극에 따른 감각 및 감성적 미각정보 처리과정의 기능적 매핑 비교)

  • Lee, Kyung Hee
    • Science of Emotion and Sensibility
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    • v.15 no.4
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    • pp.585-592
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    • 2012
  • Food is crucial for the nutrition and survival of humans. Taste system is one of the fundamental senses. Taste cells detect and respond to five basic taste modalities (sweet, bitter, salty, sour, and umami). However, the cortical processing of taste sensation is much less understood. Recently, there were many efforts to observe the brain activation in response to taste stimulation using functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and optical imaging. These different techniques do not provide directly comparable data each other, but the complementary investigations with those techniques allowed the description and understanding of the sequence of events with the dynamics of the spatiotemporal pattern of activation in the brain in response to taste stimulation. The purpose of this study is the understanding of the brain activities to taste stimuli in sensory and affective aspects and the reviewing of the recent research of the gustotopic map by functional brain mapping.

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Detection of Multidrug Resistance Using Molecular Nuclear Technique (분자핵의학 기법을 이용한 다약제내성 진단)

  • Lee, Jae-Tae;Ahn, Byeong-Cheol
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.2
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    • pp.180-189
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    • 2004
  • Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. $^{99m}Tc$-MIBI and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of PgP-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and $N-[^{11}C]acetyl-leukotriene$ E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo.

Myelin Water Fraction MRI in a Case of Clinically Probable Amyotrophic Lateral Sclerosis (근위축성측삭경화증 환자에서의 myelin water fraction MRI 1예)

  • Yang, Jiwon;Lee, Jongho;Kim, EungYeop;Shin, Dong Hoon
    • Annals of Clinical Neurophysiology
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    • v.18 no.1
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    • pp.18-20
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    • 2016
  • Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degenerative disease that clinically manifests both upper and lower motor neuron signs. However, it is unknown where and how the motor neuron degeneration begins, and conflicting hypotheses have been suggested. Recent advanced radiological techniques enable us to look into ALS neuropathology in vivo. Herein, we report a case with upper motor neuron-predominant ALS in whom the results of brain magnetic resonance imaging (MRI) and myelin water fraction MRI suggest axonal degeneration.