• 제목/요약/키워드: imaging material

검색결과 579건 처리시간 0.029초

임상적용을 위한 전자선의 선량분포 특성에 대한 고찰 (A Consideration on the Characteristics of Electron Beam Dose Distributions for Clinical Applications)

  • 차동수
    • 대한디지털의료영상학회논문지
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    • 제12권1호
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    • pp.65-69
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    • 2010
  • High energy electron beams were to concentrically dose inside a tumor and more energy is a shape decreased of dose. Therefore, it is useful to radiation therapy of a tumor. Also high energy electron beams ionized into collision with a atom in structure material of tissue and it has big changes to dose distribution by multiple scattering. The study had to establish characteristic of electron beams from interaction of electron beams and materials. Experiment method was to measure dependence of electron beam central axis for depth dose curve, field flatness and symmetry and field size dependence. The results were able to evaluate data for a datum pint of electron beam. Also radiotherapy has to be considered for not only energy pencil of lines but characteristic, electron guide and isodose curves distribution.

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CR장치와 일반 촬영 장치에서 피폭선량 측정과 촬영조건표 작성에 관한 연구

  • 김흥태;권수일;권달관;김화곤
    • 대한디지털의료영상학회논문지
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    • 제3권1호
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    • pp.76-84
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    • 1997
  • We tried to find any factor to reduce the exposure dose with ST-VA type generator which has the higher exposure dose. The guideline recommended by the provisions of IAEA regulation is being used at the time of radiation exposure and almost of those equipments used for this study had less amount of doses than those in the guideline. The FCR may be possible to decrease a certain amount of dose with effective applications of it's automatic image compensation utilities and the verifying function in PACS. Next time, it is required to add a great number of hospitals for wide range of studios and measurements, and make standard exposure Control table which will bing in practice, material decrease of dose volumes when radiation exposure.

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Primary Osteolytic Intraosseous Atypical Meningioma with Soft Tissue and Dural Invasion : Report of a Case and Review of Literatures

  • Yun, Jung-Ho;Lee, Sang-Koo
    • Journal of Korean Neurosurgical Society
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    • 제56권6호
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    • pp.509-512
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    • 2014
  • Primary intraosseous meningioma is a rare tumor, and atypical pathologic components both osteolytic lesion and dura and soft tissue invasion is extremely rare. A 65-year-old woman presented with a 5-month history of a soft mass on the right frontal area. MR imaging revealed a 4 cm sized, multilobulated, strongly-enhancing lesion on the right frontal bone, and CT showed a destructive skull lesion. The mass was adhered tightly to the scalp and dura mater, and it extended to some part of the outer and inner dural layers without brain invasion. The extradural mass and soft tissue mass were totally removed simultaneously and we reconstructed the calvarial defect with artificial bone material. The pathological study revealed an atypical meningioma as World Health Organization grade II. Six months after the operation, brain MR imaging showed that not found recurrence in both cranial and spinal lesion. Here, we report a case of primary osteolytic intraosseous atypical meningioma with soft tissue and dural invasion.

A NEW ALTERNATIVE ELLIPTIC PDE IN EIT IMAGING

  • Kim, Sungwhan
    • 대한수학회보
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    • 제49권6호
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    • pp.1291-1302
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    • 2012
  • In this paper, we introduce a new elliptic PDE: $$\{{\nabla}{\cdot}\(\frac{|{\gamma}^{\omega}(r)|^2}{\sigma}{\nabla}v_{\omega}(r)\)=0,\;r{\in}{\Omega},\\v_{\omega}(r)=f(r),\;r{\in}{\partial}{\Omega},$$ where ${\gamma}^{\omega}={\sigma}+i{\omega}{\epsilon}$ is the admittivity distribution of the conducting material ${\Omega}$ and it is shown that the introduced elliptic PDE can replace the standard elliptic PDE with conductivity coefficient in EIT imaging. Indeed, letting $v_0$ be the solution to the standard elliptic PDE with conductivity coefficient, the solution $v_{\omega}$ is quite close to the solution $v_0$ and can show spectroscopic properties of the conducting object ${\Omega}$ unlike $v_0$. In particular, the potential $v_{\omega}$ can be used in detecting a thin low-conducting anomaly located in ${\Omega}$ since the spectroscopic change of the Neumann data of $v_{\omega}$ is inversely proportional to thickness of the thin anomaly.

온라인 방사선 치료 조사야 영상 시스템의 제작과 선형성 조사 (Development of On-line Portal Imaging System and its Linearity)

  • 김성환;김재철;박인규
    • 한국의학물리학회지:의학물리
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    • 제8권2호
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    • pp.77-85
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    • 1997
  • 방사선치료에 있어서 치료시 방사선영상을 획득하여 치료조사야를 확인하는 것은 매우 중요하다. 따라서 본 연구에서는 액체유전체를 이용하여 portal 영상을 획득할 수 있는 1차원 형태의 액체전리함을 제작하고 그 선형성을 조사하였다. 액체 유전체로는 isooetane (2,2,4-TetraMethyl Pentane)을 사용하였고, 측정기의 구조는 치료용방사선발생장치의 기하학적인 구조를 고려하여 설계하였으며 위치분해능이 2mm, 측정범위가 20 cm가 되도록 설계, 제작하였다. 이렇게 완성된 이온전리함을 사용하여 실제 방사선 조사야에 측정한 결과 4.7%의 미분선형성을 나타내었다.

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Monte Carlo Studies on Mammography System

  • Ho, Dong-Su;Lee, Hyoung-Koo;Suh, Tae-Suk;Choe, Bo-Young;Kim, Song-Hyun;Kim, Do-Il
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.485-488
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    • 2002
  • In order to understand and quantitatively analyze the physical phenomena and behavior of each component of mammography system during the breast imaging, we simulated mammography imaging using Monte Carlo simulation codes. MCNP4B code was used for our simulation purpose, and we investigated the effect of target material, anode angle, filtration, peak voltage and exposure on the image quality of mammograms. From the simulation results we expect that optimized operation condition of mammography system can be found.

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종양 표적 유전자 치료 (Tumor targeted gene therapy)

  • 강주현
    • Nuclear Medicine and Molecular Imaging
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    • 제40권5호
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    • pp.237-242
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    • 2006
  • Knowledge of molecular mechanisms governing malignant transformation brings new opportunities for therapeutic intervention against cancer using novel approaches. One of them is gene therapy based on the transfer of genetic material to an organism with the aim of correcting a disease. The application of gene therapy to the cancer treatment has led to the development of new experimental approaches such as suicidal gene therapy, inhibition of oncogenes and restoration of tumor-suppressor genes. Suicidal gene therapy is based on the expression in tumor cells of a gene encoding an enzyme that converts a prodrug into a toxic product. Representative suicidal genes are Herpes simplex virus type 1 thymidine kinase (HSV1-tk) and cytosine deaminase (CD). Especially, physicians and scientists of nuclear medicine field take an interest In suicidal gene therapy because they can monitor the location and magnitude, and duration of expression of HSV1-tk and CD by PET scanner.

반절연 갈륨비소의 적외선 영상에 의한 웨이퍼성장조건 및 온도종속 퀀칭율 증명 (Evidence of Material-dependent and Temperature- dependent Quenching Rates by Infrared Imaging in S.I. GaAs)

  • 강성준
    • 대한전자공학회논문지SD
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    • 제40권7호
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    • pp.469-473
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    • 2003
  • 적외선 영상기법을 이용해 반절연 GaAs 기판 내의 EL2 영상에 대한 Photoquenching의 영향을 성장원상태(as-grown)의 샘플과 열처리 샘플을 중심으로 분석하였다. 본 논문에서 Quenching 메커니즘은 샘플에 의존적이고 또한 Quenching율은 샘플의 성장조건과 Quenching 온도에 따라 다르다는 것을 영상적으로 정확히 증명하고 있는데 이 기존의 연구내용과는 다소 상충된 새로운 내용이다.

Microwave and RF Heating for Medical Application under Noninvasive Temperature Measurement Using Magnetic Resonance

  • Nikawa, Yoshio;Ishikawa, Akira
    • Journal of electromagnetic engineering and science
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    • 제10권4호
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    • pp.244-249
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    • 2010
  • Recent development of magnetic resonance imaging (MRI) equipment enables interventional radiology (IVR) as diagnosis and treatment under MRI usage. In this paper, a new methodology for magnetic resonance (MR) scanner to apply not only diagnostic equipment but for treatment one is discussed. The temperature measuring procedure under MR is to measure phase shift of $T_1$, which is the longitudinal relaxation time of proton, for the position inside a sample material with the application of pulsed RF for heating inside the sample as artificial dielectrics. The result shows the possibility to apply MR as temperature measuring equipment and as a heating equipment for applying such as hyperthermia heating modality.

Micro-Structure Measurement and Imaging Based on Digital Holography

  • Kim, Kyeong-Suk;Jung, Hyun-Chul;Chang, Ho-Seob;Kee, Chang-Doo;Akhter, Naseem
    • 비파괴검사학회지
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    • 제30권3호
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    • pp.257-260
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    • 2010
  • Advancements in the imaging and computing technology have opened the path to digital holography for non-destructive investigations of technical samples, material property measurement, vibration analysis, flow visualization and stress analysis in aerospace industry which has widened the application of digital holography in the above fields. In this paper, we demonstrate the non-destructive investigation and micro-structure measurement application of digital holography to the small particles and a biological sample. This paper gives a brief description of the digital holograms recorded with this system and illustratively demonstrated.