• Title/Summary/Keyword: x-ray CT

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Defect Detection of Brazing Joint in Heat Exchanger Using X-ray Image (X-선을 이용한 열교환기 브레이징 접합부 결함 검출)

  • Kim, Jin-Young;Seo, Sang-Woo
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.10
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    • pp.1044-1050
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    • 2011
  • The quality of brazing joints is one of the most important factors that have an effect on the performance of the brazing joint-based heat exchangers with the growing use in industry recently. Therefore, it is necessary to inspect the brazing joints in order to guarantee the performance of the heat exchangers. This paper presents a non-destructive method to inspect the brazing joints of the heat exchangers using X-ray. Firstly, X-ray cross-sectional images of the brazing joints are obtained by using CT (Computerized Tomography) technology. Cross-sectional image from CT is more useful to detect the inner defects than the traditional transmitted X-ray image. Secondly, the acquired images are processed by an algorithm proposed for the defect detection of brazing joint. Finally, two types of brazing joint are examined in a series of experiments to detect the defects in brazing joints. The experimental results show that the proposed algorithm is effective for defect detection of the brazing joints in heat exchangers.

Making Human Phantom for X-ray Practice with 3D Printing (3D 프린팅을 활용한 일반 X선 촬영 실습용 인체 팬텀 제작)

  • Choi, Woo Jeon;Kim, Dong Hyun
    • Journal of the Korean Society of Radiology
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    • v.11 no.5
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    • pp.371-377
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    • 2017
  • General phantom for practical X-ray photography Practical phantom is an indispensable textbook for radiology, but it is difficult for existing commercially available phantom to be equipped with various kinds of phantom because it is an expensive import. Using 3D printing technology, I would like to make the general phantom for practical X-ray photography less expensive and easier. We would like to use a skeleton model that was produced based on CT image data using a 3D printer of FDM (Fused Deposition Modeling) method as a phantom for general X-ray imaging. 3D slicer 4.7.0 program is used to convert CT DICOM image data into STL file, convert it to G-code conversion process, output it to 3D printer, and create skeleton model. The phantom of the completed phantom was photographed by X - ray and CT, and compared with actual medical images and phantoms on the market, there was a detailed difference between actual medical images and bone density, but it could be utilized as a practical phantom. 3D phonemes that can be used for general X-ray practice can be manufactured at low cost by utilizing 3D printers which are low cost and distributed and free 3D slicer program for research. According to the future diversification and research of 3D printing technology, it will be possible to apply to various fields such as health education and medical service.

The Study on the Implementation of the X-Ray CT System Using the Cone-Beam for the 3D Dynamic Image Acquisition (3D 동영상획득을 위한 Cone-Beam 형 X-Ray CT 시스템 구현에 관한 연구)

  • Jeong, Chan-Woong;Jun, Kyu-Suk
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.4
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    • pp.370-374
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    • 2009
  • In this paper, we presents a new cone beam computerized tomography (CB CT) system for the reconstruction of 3 dimensional dynamic images. The system using cone beam has less the exposure of radioactivity than fan beam, relatively. In the system, the reconstruction 3-D image is reconstructed with the radiation angle of X-ray in the image processing unit and transmitted to the monitor. And in the image processing unit, the Three Pass Shear Matrices, a kind of Rotation-based method, is applied to reconstruct 3D image because it has less transcendental functions than the one-pass shear matrix to decrease a time of calculations for the reconstruction 3-D image in the processor. The new system is able to get 3~5 3-D images a second, reconstruct the 3-D dynamic images in real time.

Application of X-ray Computer Tomography (CT) in Cattle Production

  • Hollo, G.;Szucs, E.;Tozser, J.;Hollo, I.;Repa, I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.12
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    • pp.1901-1908
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    • 2007
  • The aim of this series of experiments was to examine the opportunity for application of X-ray computer tomography (CT) in cattle production. Firstly, tissue composition of M. longissimus dorsi (LD) cuts between the $11-13^{th}$ ribs (in Exp 1. between the $9-11^{th}$ ribs), was determined by CT and correlated with tissue composition of intact half carcasses prior to dissection and tissue separation. Altogether, 207 animals of different breeds and genders were used in the study. In Exp. 2 and 3, samples were taken from LD cuts, dissected and chemical composition of muscle homogenates was analysed by conventional procedures. Correlation coefficients were calculated among slaughter records, tissues in whole carcasses and tissue composition of rib samples. Results indicated that tissue composition of rib samples determined by CT closely correlated with tissue composition results by dissection of whole carcasses. The findings revealed that figures obtained by CT correlate well with the dissection results of entire carcasses (meat, bone, fat). Close three-way coefficients of correlation (r = 0.80-0.97) were calculated among rib eye area, volume of cut, pixel-sum of adipose tissue determined by CT and intramuscular fat or adipose tissue in entire carcasses. Estimation of tissue composition of carcasses using equations including only CT-data as independent variables proved to be less reliable in prediction of lean meat and bone in carcass ($R^2 = 0.51-0.86$) than for fat (($R^2 = 0.83-0.89$). However, when cold half carcass weight was also included in the equation, the coefficient of determination exceeded $R^2 = 0.90$. In Exp. 3 tissue composition of rib samples by CT were compared to the results of EUROP carcass classification. Findings revealed that CT analysis has higher predictive value in estimation of actual tissue composition of cattle carcasses than EUROP carcass classification.

Identification and Three-Dimensional Characterization of Micropore Networks Developed in Granite using Micro-Focus X-ray CT

  • Choo, Chang-Oh;Takahashi, Manabu;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.24 no.2
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    • pp.179-189
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    • 2014
  • We analyzed the three-dimensional distribution of micropores and internal structures in both fresh and weathered granite using micro-focus X-ray computed tomography (micro-CT). Results show that the pore radius in fresh granite is mostly in the range of $17-50{\mu}m$, the throat radius is in the range of $5-25{\mu}m$, and the coordination number (CN) of pores is less than 10. In contrast, the pore radius in weathered granite is mostly in the range of $20-80{\mu}m$, the throat radius is in the range of $8-30{\mu}m$, and the CN is less than 12. In general, a positive linear relationship exists between pore radius and CN. In addition, both the size and the density of pores increase with an increasing degree of rock weathering. The size of the throats that connect the pores also increases with an increasing degree of weathering, which induces fracture propagation in rocks. Micro-CT is a powerful and versatile approach for investigating the three-dimensional distributions of pores and fracture structures in rocks, and for quantitatively assessing the degree of pore connectivity.

The Retrospective Study of Essential X-ray in Emergency Multiple Trauma Patients (응급 다발성 외상환자의 기본적 방사선 촬영부위에 관한 조사연구)

  • Yoo, Beong-Gyu
    • Journal of radiological science and technology
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    • v.19 no.2
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    • pp.51-57
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    • 1996
  • Radiography should be used judiciously and should not delay patients resuscitation. In the patient with emergency multiple trauma, three radiography should be obtained-cervical spine, anteroposterior(AP) chest, and AP pelvis. These examinations can be done in the resuscitation area, usually with a portable X-ray unit, but should not interrupt the resuscitation process. A retrospective study was carried on 157 emergency multiple trauma patients who were admitted to Yong Dong Severance Hospital from January, to December in 1995. I analyzed the types of X-ray examinations in emergency multiple trauma patients, and classified the patients by disoriented group of mentality. The results were as follows: 1. The subjects were 7.1%(157patients) of 2,208 trauma patients(7.3%) in total 30,085 emergency patients. 2. Male to female ratio was 2.57 : 1. The age distribution was highest from 31 years to 40 years(28.0% ). 3. The peak time of patient's entrance in emergency center was between 8 : 00 pm and 2 : 00 am(36.9%), and second peak time was between 2 : 00 pm and 8 : 00 pm (29.3%). 4. According to the injury type, traffic accident, motorcycle accident and falling down were 71.3%, 8.3% and 20.4% respectively. 5. According to the exposure rate of Computed Tomography, chest CT, cervical CT pelvis CT and brain CT were 39.5%, 24.2%, 69.4% and 51.6% respectively.

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Nondestructive Evaluation of Microstructure of SiCf/SiC Composites by X-Ray Computed Microtomography

  • Kim, Weon-Ju;Kim, Daejong;Jung, Choong Hwan;Park, Ji Yeon;Snead, Lance L.
    • Journal of the Korean Ceramic Society
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    • v.50 no.6
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    • pp.378-383
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    • 2013
  • Continuous fiber-reinforced ceramic matrix composites (CFCCs) have a complex distribution of porosity, consisting of interfiber micro pores and interbundle/interply macro pores. Owing to the complex geometry of the pores and fiber architecture, it is difficult to obtain representative microstructural features throughout the specimen volume with conventional, destructive ceramographic approaches. In this study, we introduce X-ray computed microtomography (X-ray ${\mu}CT$) to nondestructively analyze the microstructures of disk shaped and tubular $SiC_f$/SiC composites fabricated by the chemical vapor infiltration (CVI) method. The disk specimen made by stacking plain-woven SiC fabrics exhibited periodic, large fluctuation of porosity in the stacking direction but much less variation of porosity perpendicular to the fabric planes. The X-ray ${\mu}CT$ evaluation of the microstructure was also effectively utilized to improve the fabrication process of the triple-layered tubular SiC composite.

Development of Dicom Image Saving and Retrieval Module in Remote Oriental Medicine Examination System (한방 원격 검진 시스템에서의 DICOM에 의거한 이미지데이터의 저장 및 검색모듈 개발)

  • 김인태;이혜정;정성태
    • Proceedings of the Korea Multimedia Society Conference
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    • 1998.10a
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    • pp.321-326
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    • 1998
  • 본 연구에서는 환자와 한의사, 방사선 전문의 간에 초고속 통신망을 이용하여 원격으로 환자의 질환 상태를 파악하고 이에 따른 처방전을 내릴 수 있도록 하는 한방 원격 검진 시스템에서 환자의 X-ray 사진, CT 사진 등의 방사선 이미지들을 DICOM 프로토콜에 의거하여 저장하고 검색할 수 있도록 해주는 시스템을 구현하였다. 본 연구에서는 이미지 처리 및 관리 모듈을 Java 언어를 이용하여 구현함으로써 방사선 전문의와 한의사들이 컴퓨터의 기종에 관계없이 웹브러우저를 사용하여 환자의 X-ray나 CT 등의 방사선 사진을 살펴볼 수 있도록 하였다.

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A Study Transform Coding of Medical Image Using Adaptive Quantization Method (적응 양자화를 위한 의료 영상 정보의 변환 부호화에 관한 연구)

  • 한영오;박장춘
    • Journal of Biomedical Engineering Research
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    • v.10 no.3
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    • pp.243-252
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    • 1989
  • In this study, medical images, which are X-ray image and CT image, are compressed by the adam live coding technique. The medical images may be treated as special ones, because they are different from general images in many respects. The statistical characteristics that medical images only have in transform domain are analyzed, and then the improved quantization method is proposed for medical images. For chest X-ray image and CT head image, the better results are obtained by the improved adaptive coding technique.

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A study on segmentation of medical image using fuzzy set theory (퍼지 이론을 이용한 의료 영상 특징 추출에 관한 연구)

  • 김형석;한영오;박상희
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.741-745
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    • 1991
  • This paper describes a feature extraction in digitized chest X-ray image and CT head Image. There are Extraction, Thresholding, Region G rowing, Split-Merge and Relaxation in feature extraction technique. In this study, Region Growing System was realized and Fuzzy Set Theory was applied in order to extract the vague region which the conventional method has difficulties in extracting. The performance of proposed algorithm was proved by being applied to chest X-ray image and CT head image.

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