범용 소프트웨어를 사용한 산업용 3차원 X-ray Computed Tomography의 툴 개발

최형석,양윤기 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.3

With the deployment of 4-th generation industrial revolution, the computer based manufacturing technologiesemploying advanced IT technology are much more popular than any other past years. In this research, some novel S/Wtechnologies related to the industrial X-ray CT (computed tomography) for the inspection of the industrial parts areintroduced. First, newly constructed industrial X-ray CT is presented in this paper, where some basic principles andfunctions of the CT are described. Then some research platforms are developed to generate more advanced functionalitiesof the industrial CT. Especially, the data transform from CT to general S/W such as Matlab is conducted. And based onthis techniques, some supplementary S/W platform such as GUI (graphical user interface) of the CT S/W and some 3Dvoxel based image processing technologies can be developed in this paper. The industrial CT is one of the rare research items and it’s values can be much more enhanced when it is used withadvanced IT technologies. 4차 산업 혁명 시대를 맞이하여, 최근 기계, 전자 부품의 설계, 제조, 검사에 첨단 IT 기술을 융합하는 사례가 늘고 있다. 본 연구에서는 최근에 구축된 산업용 X-ray CT (computed tomography)를 사용한 산업용 부품의 검사에 대한 최신기술에대해서 다룬다. 먼저 구축된 첨단의 최신 산업용 CT의 구조와 원리에 대해서 설명하며, 이러한 장비의 역할과 성능에 대해서설명하고, 본 장비의 분석기법을 보완하기 위한 새로운 연구기반의 구축에 대해서 다룬다. 특히 장비의 출력데이터를 Matlab과 같은 범용 연구 툴로 전송하여 연구를 진행할 수 있는 기반을 구축하며, 이를 토대로 기존의 운용 소프트웨어가 제공하지못했던 보조적인 3D user interface 와 3차원 영상처리를 위한 플랫폼을 구축하는 연구를 진행 하였다. 산업용 3차원 X-ray는 아직 소개 된지 얼마 되지 않은 첨단의 고가의 장비로서 이를 활용할 연구의 종류와 내용이 매우 풍부한 주제로, 이러한기초적인 연구기반은 추후의 보다 발전적인 연구를 위한 아주 유용한 토대가 될 것으로 판단된다.

치과 임프란트 치료 계획을 위한 나선형 일반 단층촬영과 전산화 단층촬영시 흡수선량 및 유효선량 평가

홍병희,한원정,김은경 대한구강악안면방사선학회 2001 Imaging Science in Dentistry Vol.31 No.3

Objectives : To evaluate the absorbed and effective doses of spiral and computed tomography for the dental implant planning. Materials and Methods : For radiographic projection, TLD chips were placed in 22 sites of humanoid phantom to record the exposure to skin and the mean absorbed dose to bone marrow, thyroid, pituitary, parotid and submandibular glands and nesophagus. Effective dose was calculated, using the method suggested by Frederiksen et al.. Patient situations of a single tooth gap in upper and lower midline region, edentulous maxilla and mandible were simulated for spiral tomography.35 axial slices(maxilla) and 40 axial slices (mandible) with low and standard dose setting were used for computed tomography. All the radiographic procedures were repeated three times. Results : The mean effective dose in case of maxilla was 0.865 mSv,0.452 mSv,0.136 mSv and 0.025 mSv, in spiral tomography of complete edentulous maxilla, computed tomography with standard mAs , computed nomography with low mAs and spiral tomography of a single tooth gap (p〈0.05). That in case of mandible was 0.614 mSv, 0.448 mSv, 0.137 mSv and 0.036 mSv, in spiral tomography of complete edentulous mandible, computed tomography with standard mAs, computed tomography with low mAs and spiral tomography of a single tooth gap (p〈0.05). Conclusions : Based on these results, it can be concluded that low mAs computed tomography is recommended instead of spiral tomography for the complete edentulous maxilla and mandible dental implant treatment planning. (Korean J Oral Maxillofac Radiol 2001; 31 : 165-73)

3차원 X-ray 단층 화상을 이용한 스카른 광석의 정량분석 연구

정미희 ( Mi Hee Jeong ),조상호 ( Sang Ho Cho ),정수복 ( Soo Bok Jeong ),김영훈 ( Young Hun Kim ),박재구 ( Jai Koo Park ),금자승비고 ( Katsuhiko Kaneko ) 한국광물학회 2010 광물과 암석 (J.Miner.Soc.Korea) Vol.23 No.3

스카른 Zn-Pb-Cu 복합광석을 구성하는 주요 구성 광물의 정량분석을 목적으로, 마이크로 포커스 X-ray 단층촬영 장비를 이용한 스카른 복합광석의 3차원 비파괴검사를 수행하였다. X-ray 단층화상의 화상결함을 감소시키고자 제안된 화상보정법을 이용하여 화상들을 보정한 후에 3차원으로 재구성하였다. 주사전자현미경(SEM)에 의한 표면분석과 보정된 X-ray 단층화상을 비교하여 주요광물에 대한 CT 값의 범위를 결정하였다. 재구성화상 내 전체 광물의 체적비율을 분석한 결과, 황화광물 20.5%, 맥석광물 79.5%로 평가되었다. X-ray 3차원 단층화상 정량분석법은 광석 내 유용광물의 부존 형상과 회수율 분석에 유용하게 적용될 것으로 기대된다. A micro-focus X-ray computed tomography (CT) was employed to determine quantitative phase analysis of skarn Zn-Pb-Cu ore by nondestructive visualization of the internal mineral distribution of a skarn ore. The micro CT images of the ore were calibrated to remove beam hardening artifacts, and compared with its scanning electron microscope (SEM) images to set the threshold of CT number range covering sulfide ore minerals. The volume ratio of sulfide and gangue minerals was calculated 20.5% and 79.5%, respectively. The quantitative 3D X-ray CT could be applied to analyse the distribution of economic minerals and their recovery.

Comparison of X-ray Computed Tomography and Magnetic Resonance Imaging to Detect Pest-Infested Fruits: A Pilot Study

김태윤,이재기,선광민,박병건,박해준,최득수,예성준 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.2

Non-destructive testing (NDT) technology is a widely used inspection method for agricultural products. Compared with the conventional inspection method, there is no extensive sample preparation for NDTtechnology, and the sample is not damaged. In particular, NDT technology is used to inspect the internalstructure of agricultural products infested by pests. The introduction and spread of pests during theimport and export process can cause significant damage to the agricultural environment. Until now, pestdetection in agricultural products and quarantine processes have been challenging because they usedexternal inspection methods. However, NDT technology is advantageous in these inspection situations. Inthis pilot study, we investigated the feasibility of X-ray computed tomography (X-ray CT) and magneticresonance imaging (MRI) to identify pest infestation in agricultural products. Three kinds of artificiallypest-infested fruits (mango, tangerine, and chestnut) were non-destructively inspected using X-ray CTand MRI. X-ray CT was able to identify all pest infestations in fruits, while MRI could not detect the pestinfested chestnut. In addition, X-ray CT was superior to the quarantine process than MRI based on thecontrast-to-noise ratio (CNR), image acquisition time, and cost. Therefore, X-ray CT is more appropriatefor the pest quarantine process of fruits than MR

Wave Propagation Simulation Based on the Fourier Diffraction Integral for X-Ray Refraction Contrast Imaging-Computed Tomography

Won-Seok Chang,Jong-Ki Kim,Jin-Ho Cho,Jae-Hong Lim 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.6

With the advent of coherent X-ray sources, X-ray refraction has begun to be utilized for X-ray imaging of unprecedented sensitivity. The aim of this study was to develop a wave propagation simulator that provides a map of X-ray refraction after passing through an object. We applied the Fresnel diffraction integral for calculating the propagated wave and then obtained the refraction map by differentiating the phase in the refraction-analyzing direction. The simulation was validated by comparing the computed tomography (CT) reconstruction of a virtual phantom with its map of refractive index: the deviations were below 0.7% for soft tissues under our test condition. The simulator can be used for testing and developing highly-sensitive X-ray imaging techniques based on X-ray refraction analysis prior to experimentation.

X-ray tomography 분석과 기계 학습을 활용한 금속 3D 프린팅 소재 내의 기공 형태 분류

김은아,권세훈,양동열,유지훈,김권일,이학성,Kim, Eun-Ah,Kwon, Se-Hun,Yang, Dong-Yeol,Yu, Ji-Hun,Kim, Kwon-Ill,Lee, Hak-Sung 한국분말재료학회 (*구 분말야금학회) 2021 한국분말재료학회지 (KPMI) Vol.28 No.3

Metal three-dimensional (3D) printing is an important emerging processing method in powder metallurgy. There are many successful applications of additive manufacturing. However, processing parameters such as laser power and scan speed must be manually optimized despite the development of artificial intelligence. Automatic calibration using information in an additive manufacturing database is desirable. In this study, 15 commercial pure titanium samples are processed under different conditions, and the 3D pore structures are characterized by X-ray tomography. These samples are easily classified into three categories, unmelted, well melted, or overmelted, depending on the laser energy density. Using more than 10,000 projected images for each category, convolutional neural networks are applied, and almost perfect classification of these samples is obtained. This result demonstrates that machine learning methods based on X-ray tomography can be helpful to automatically identify more suitable processing parameters.

X-ray CT reconstruction

Tao Quang Bang,Insu Jeon 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

X-ray Computer tomography (CT) has provided a unique window into the anatomy of the human body since the invention of the CT scanner by Hounsfield in 1972. Nowadays, X-ray CT is widely used in many applications, can reconstruct the cross-section of object from its projections, not only a well-recognized imaging modality in medicine but also an essential one in industrial quality control and nondestructive evaluation. However, present CT techniques only consider increase the quality of CT images so a huge number of X-ray projections are needed as well as increase radiation dose and X-ray taking time for patient. To solve these problems, we developed image interpolation technique to reconstruction image from limited X-ray projections. The advantage of this technique was to decreased radiation dose and X-ray taking time for patient as minimal as possible, while increase the quality of CT images. In this study, we applied our method to biomaterial and aluminum phantom

X-ray Computed Tomography on Larger Diameter Timber Timber than Digital Detector

Chul Ki Kim,Jun Jae Lee,Jung Kwon Oh 한국목재공학회 2013 목재공학 Vol.41 No.5

X-ray computed tomography is a very powerful nondestructive technique in safety inspection of historic timber building. But, in field, various testing condition makes it difficult to carry out X-ray CT testing. Limited size in X-ray digital detector is one of the problems. In this study, a pitch pine disk with two holes was used to know how imperfection in X-ray projection affects CT image resolution. Using various number of projections, CT image was reconstructed by filtered back projection method, and then it was investigated how many projection is required to identify the holes in different location. Two artificial holes could be differently detected according to their location in cross section of specimen. One hole in center part of specimen was identified using more than 9 radiographs, but the other one which located in outer part of cross section could not be detected until more than 36 projections were used. Even though there is data missing in outer part of cross section due to limited size of detector, the center part of CT image could be reconstructed well and the resolution of outer part became higher with increase of the number of projections. For field application, the number of projections for CT image reconstruction needs to be decided with consideration of another nondestructive testing and the location of interest.

Interpolation technique for CT reconstruction

Tao Quang Bang,Insu Jeon(전인수) 한국자동차공학회 2011 한국자동차공학회 지부 학술대회 논문집 Vol.2011 No.5

X-ray computed tomography (CT) is a well established visualization technique in medicine and nondestructive testing. However, since CT scanning requires sampling of radiographic projections from different viewing angles, common CT systems with mechanically moving parts are too slow for dynamic imaging, for instance of multiphase flows or live animals. Projections are acquired electronically using a linear array of solid-state detectors and an X-ray source that rotates around the patient. Therefore, decrease number of X-ray projections in X-ray CT reconstruction process to obtain reasonable CT images is very challenging. In this study, we present a linear interpolation technique for tomographic reconstruction of a sample from vastly fewer angular projections than required by conventional algorithms. In this research, we present reconstructions from an experimental X-ray CT scan of a phantom that follows to two steps: X-ray images will be interpolated and using it for CT reconstruction based upon Ordered Subsets Expectation Maximization (OSEM) method.

소형 동물의 생체 촬영을 위한 고해상도 Micro-CT 시스템의 개발

박정진,이수열,조민형,Park, Jeong-Jin,Lee, Soo-Yeol,Cho, Min-Hyoung 대한의용생체공학회 2007 의공학회지 Vol.28 No.1

Recently, small-animal imaging technology has been rapidly developed for longitudinal screening of laboratory animals such as mice and rats. One of newly developed imaging modalities for small animals is an x-ray micro-CT (computed tomography). We have developed two types of x-ray micro-CT systems for small animal imaging. Both systems use flat-panel x-ray detectors and micro-focus x-ray sources to obtain high spatial resolution of $10{\mu}m$. In spite of the relatively large field-of-view (FOV) of flat-panel detectors, the spatial resolution in the whole-body imaging of rats should be sacrificed down to the order of $100{\mu}m$ due to the limited number of x-ray detector pixels. Though the spatial resolution of cone-beam CTs can be improved by moving an object toward an x-ray source, the FOV should be reduced and the object size is also limited. To overcome the limitation of the object size and resolution, we introduce zoom-in micro-tomography for high-resolution imaging of a local region-of-interest (ROI) inside a large object. For zoom-in imaging, we use two kinds of projection data in combination, one from a full FOV scan of the whole object and the other from a limited FOV scan of the ROI. Both of our micro-CT systems have zoom-in micro-tomography capability. One of both is a micro-CT system with a fixed gantry mounted with an x-ray source and a detector. An imaged object is laid on a rotating table between a source and a detector. The other micro-CT system has a rotating gantry with a fixed object table, which makes whole scans without rotating an object. In this paper, we report the results of in vivo small animal study using the developed micro-CTs.