• Title, Summary, Keyword: in-vivo 영상

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Functional Imaging of the Multidrug Resistance In Vivo (기능적 영상술을 이용한 다약제 내성의 체내 진단)

  • Lee, Jea-Tae
    • 대한핵의학회:학술대회논문집
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    • pp.66-75
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    • 2001
  • Although diverse mechanisms are involved in multidrug resistance for chemotherapeutic drugs, the development of cellular P-glycoprotein(Pgp) and multidrug-resistance associated protein (MRP) are important factors in the chemotherapy failure to cancer. Various detection assays provide information about the presence of drug efflux pumps at the mRNA and protein levels. However these methods do not yield information about dynamic function of Pgp and MRP un vivo. Single photon emission tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transport. $^{99m}Tc$-sestaMIBl 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. Results obtained from recent publications are reviewed to confirm the feasibility of using SPECT and PET to study the functionality of MDR transporters in vivo.

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Usefulness of Twinkling Artifacts in Color Doppler Ultrasonography (컬러 도플러 초음파에서 Twinkling artifacts의 유용성)

  • Sim, Hyun-Sun;Kwon, Kyung-Tae
    • The Journal of the Korea Contents Association
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    • v.16 no.10
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    • pp.291-298
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    • 2016
  • The aim of the study was to investigate the diagnostic value of the color Doppler twinkling artifact in disease of urinary system. The intensity of twinkling artifact(TA) with color Doppler was classified into 3 levels, 0(non-TA) to 3(distinct TA). In the in vitro study, acorn jelly with various materials on top was examined using color Doppler at B-mode sonography in a water bath for TA. 31 patients with diagnosis of urinary calculi(renal stones 16, urinary stones 15) based on B-mode sonography were studied in vivo for TA. The materials with rough surfaces such as salt, screw and cubics at B-mode sonography with color Doppler contributed to causing TA. At B-mode sonography without color Doppler 37% of renal stones and 60% of ureter stones were detected. but at B-mode sonography with color Doppler TA was demonstrated for all cases. Superficial roughness of materials affected occurrence of TA at B-mode sonography with color Doppler. Therefore, TA at B-mode sonography without color Doppler could play a role in confident diagnosis of the disease of urinary system.

Background Gradient Correction using Excitation Pulse Profile for Fat and $T_2{^*}$ Quantification in 2D Multi-Slice Liver Imaging (불균일 자장 보정 후처리 기법을 이용한 간 영상에서의 지방 및 $T_2{^*}$ 측정)

  • Nam, Yoon-Ho;Kim, Hahn-Sung;Zho, Sang-Young;Kim, Dong-Hyun
    • Investigative Magnetic Resonance Imaging
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    • v.16 no.1
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    • pp.6-15
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    • 2012
  • Purpose : The objective of this study was to develop background gradient correction method using excitation pulse profile compensation for accurate fat and $T_2{^*}$ quantification in the liver. Materials and Methods: In liver imaging using gradient echo, signal decay induced by linear background gradient is weighted by an excitation pulse profile and therefore hinders accurate quantification of $T_2{^*}$and fat. To correct this, a linear background gradient in the slice-selection direction was estimated from a $B_0$ field map and signal decays were corrected using the excitation pulse profile. Improved estimation of fat fraction and $T_2{^*}$ from the corrected data were demonstrated by phantom and in vivo experiments at 3 Tesla magnetic field. Results: After correction, in the phantom experiments, the estimated $T_2{^*}$ and fat fractions were changed close to that of a well-shimmed condition while, for in vivo experiments, the background gradients were estimated to be up to approximately 120 ${\mu}T/m$ with increased homogeneity in $T_2{^*}$ and fat fractions obtained. Conclusion: The background gradient correction method using excitation pulse profile can reduce the effect of macroscopic field inhomogeneity in signal decay and can be applied for simultaneous fat and iron quantification in 2D gradient echo liver imaging.

In Vivo High Resolution NMR Imaging by Using Surface Gradient Coil (평면 경사자계 코일을 사용한 고분해능 NMR 생체 영상법에 관한 연구)

  • Yi, Jeong-Han;Oh, Woo-Jin;Cho, Zang-Hee
    • Proceedings of the KOSOMBE Conference
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    • v.1990 no.11
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    • pp.48-51
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    • 1990
  • A new in vivo high resolution imaging method which is performed with a newly developed three channel surface gradient coil (SGC) is described. The surface gradient coil can produce more than an order of magnitude stronger gradient fields with good linearity within a limited imaging region. To increase the signal to noise ratio (SNR), we have developed an RF coil integrated surface gradient coil set. In this paper, the geometrical structures and characteristics of the proposed surface gradient coil are discussed and experimentally obtained high resolution images ($50\;{\mu}m$ to $100\;{\mu}m$) of a water filled phantom and a human volunteer's knee using the new surface RF coil integrated SGC set are presented for the demonstration of the in vivo high resolution imaging capability of the new imaging method.

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Feasibility of $In$ $vivo$ Proton Magnetic Resonance Spectroscopy for Lung Cancer (폐암의 생체 수소자기공명분광법의 실행가능성)

  • Yoon, Soon-Ho;Park, Chang-Min;Lee, Chang-Hyun;Song, In-Chan;Lee, Hyun-Ju;Goo, Jin-Mo
    • Investigative Magnetic Resonance Imaging
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    • v.16 no.1
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    • pp.40-46
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    • 2012
  • Purpose : To investigate the feasibility of in vivo proton magnetic resonance spectroscopy (MRS) for evaluation of lung cancer. Materials and Methods: This prospective study was approved by the institutional review board of our hospital and informed consent was obtained in all patients. Ten patients (7 men, 3 women; mean age, 64.4) with pathologicallyproven lung cancer (mean, 56.8 mm; range, 44-77 mm) were enrolled to 1.5 T MRS using a single-voxel respiration-triggered point-resolved spectroscopic sequence. Technical success rate and the reason of technical failure, if any, were investigated. Results: Out of 10 lung cancers, analyzable MRS spectra were obtained in 8 tumors (technical success rate, 80%). Two MRS datasets were not able to be analyzed due to serious baseline distortion. Choline and lipid signals were detected as major metabolites in analyzable MRS spectra. Conclusion: In vivo proton MRS method using a single-voxel respiration-triggered point-resolved spectroscopic sequence is feasible in obtaining the MR spectra of lung cancer because these spectra were analyzable and high success rate was shown in our study although there was the limitation of small patient group.

In vivo Dendritic Cell Migration Tracking Using Near-infrared (NIR) Imaging (Near-infrared (NIR) 영상기법을 이용한 생체 내 수지상세포의 이동)

  • Lee, Jun-Ho;Jung, Nam-Chul;Lee, Eun Gae;Lim, Dae-Seog
    • KSBB Journal
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    • v.27 no.5
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    • pp.295-300
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    • 2012
  • Matured dendritic cells (DCs) begin migration with their release from the bone marrow (BM) into the blood and subsequent traffic into peripheral lymphoid and non-lymphoid tissues. Throughout this long movement, migrating DCs must apply specialized skills to reach their target destination. Non-invasive in vivo cell-tracking techniques are necessary to advance immune cell-based therapies. In this study, we used a DiD cell-tracking solution for in vivo dendritic cell tracking in naive mice. We tracked DiD (non-invasive fluorescence dye)-labeled mature dendritic cells using the Near Infrared (NIR) imaging system in normal mice. We examined the immunophenotype of DiD-labeled cells compared with non-labelled mature DCs, and obtained time-serial images of NIR-DC trafficking after mouse footpad injection. In conclusion, we confirmed that DiD-labeled DCs migrated into the popliteal lymph node 24 h after the footpad injection. Here, these data suggested that the cell tracking system with the stable fluorescence dye DiD was useful as a cell tracking tool to advance dendritic cell-based immunotherapy.

Medial Longitudinal Fasciculus on MRI in a Patient with Internuclear Ophthalmoparesis: A Case Report (신경핵사이 눈근육마비환자에서 자기공명영상에서의 내측세로다발: 증례 보고)

  • Kim, Sung Min;Kim, Ho Kyun;Lee, Hui Joong
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.2
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    • pp.167-170
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    • 2014
  • The medial longitudinal fasciculus (MLF) is myelinated composite tract, lying near the midline, ventral to periaqueductal grey matter that plays a key role in coordinating eye movements. A lesion of the MLF results in an ipsilateral adduction deficit and a contralateral abducting nystagmus, referred to as an internuclear ophthalmoparesis. The blended tract with adjacent white matter in pons and midbrain is indistinguishable on brain imaging such as CT and MRI. Until now, to the best of our knowledge, MLF is not delineated on in vivo MRI. We present a case showing the whole connecting courses of MLF lesion on MRI in a patient with inflammatory demyelinating disorder.

Implementation of a backend system for real-time intravascular ultrasound imaging (실시간 혈관내초음파 영상을 위한 후단부 시스템 구현)

  • Park, Jun-Won;Moon, Ju-Young;Lee, Junsu;Chang, Jin Ho
    • The Journal of the Acoustical Society of Korea
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    • v.37 no.4
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    • pp.215-222
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    • 2018
  • This paper reports the development and performance evaluation of a backend system for real-time IVUS (Intravascular Ultrasound) imaging. The developed backend system was designed to minimize the amount of logic and memory usage by means of efficient LUTs (Look-up Tables), and it was implemented in a single FPGA (Field Programmable Gate Array) without using external memory. This makes it possible to implement the backend system that is less expensive, smaller, and lighter. The accuracy of the backend system implemented was evaluated by comparing the output of the FPGA with the result computed using a MATLAB program implemented in the same way as the VHDL (VHSIC Hardware Description Language) code. Based on the result of ex-vivo experiment using rabbit artery, the developed backend system was found to be suitable for real-time intravascular ultrasound imaging.

In Vivo Nuclear Imaging of Apoptosis (세포고사의 핵의학영상)

  • Lee, Tae-Sup;Cheon, Gi-Jeong
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.2
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    • pp.190-197
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    • 2004
  • Apoptosis plays a role in the pathophysiology of many kinds of diseases and in the response of treatment. Compared to the necrosis, the apoptosis is a genetically controlled and energy-dependent process which removes the unwanted cells from the body; programmed cell death or cell suicide. During the apoptosis, phosphatidylserine is expressed in the cytoplasmic outer membrane in the early phase. Annexin V, an endogenous human protein (MW=35 kD), has an affinity of about $10^{-9}\;M$ for the phosphatidylserine exposed on the outer membrane of apoptotic cells. Annexin V can be radiolabeled with $^{99m}Tc$ by HYNIC or EC chelators, which can be used as an radiotracer for the in vivo imaging of apoptosis. In this article, we reviewed the apoptosis, radiolabeling of annexin V, and the experimental and clinical data using annexin V imaging.

MR Contrast Agents and Molecular Imaging (MR조영제와 분자영상)

  • Moon, Woo-Kyung
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.2
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    • pp.205-208
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    • 2004
  • The two major classes of magnetic resonance (MR) contrast agents are paramagnetic contrast agents, usually based on chelates of gadolinium generating T1 positive signal enhancement, and super-paramagnetic contrast agents that use mono- or polycrystalline iron oxide to generate strong T2 negative contrast in MR images. These paramagnetic or super-paramagnetic complexes are used to develop new contrast agents that can target the specific molecular marker of the cells or tan be activated to report on the physiological status or metabolic activity of biological systems. In molecular imaging science, MR imaging has emerged as a leading technique because it provides high-resolution three-dimension maps of the living subject. The future of molecular MR imaging is promising as advancements in hardware, contrast agents, and image acquisition methods coalesce to bring high resolution in vivo imaging to the biochemical sciences and to patient care.