• Title/Summary/Keyword: Spin image

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A New Fast Spin Echo MR Imaging Technique for the Simultaneous Dual Echo Image Acquisition (Dual Echo 영상의 동시 획득을 위한 새로운 Fast Spin Echo 자기 공명 영상법)

  • 조민형;이수열
    • Journal of Biomedical Engineering Research
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    • v.19 no.1
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    • pp.91-100
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    • 1998
  • In magnetic resonance imaging, the fast spin echo imaging technique is a widely used clinical imaging method. since its scanning time is much shorter than the conventional spin echo imaging and it gives the almost same image quality. However, the fast spin echo technique has two times longer imaging time for the dual echo acquisition which can obtain a spin density image and a T-give the same qulity images at the single echo imaging time. T he proposed technique reduces the imaging time by overlapping most of were obtained at the 0.3T permanent MRI system are presented.

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Evaluation of the Image Blurring in the Fast Spin Echo Technique ccording to Variation of the ETL (고속스핀에코기법을 이용한 MRI검사에서 ETL 변화에 따른 영상 blurring의 평가)

  • Kwon, Soon-Yong;Lim, Woo-Taek;Kang, Chung-Hawn;Kim, Kyeong-Soo;Kim, Soon-Bae;Kim, Hyun-Soo
    • Korean Journal of Digital Imaging in Medicine
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    • v.15 no.2
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    • pp.55-61
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    • 2013
  • The purpose of this study is to evaluate image blurring according to variation of the ETL and propose the clinically appropriate ETL range. SIEMENS MAGNETOM Skyra 3.0T and 20 channel head coil were used for the study. MRI phantom was kept the lines horizontally to three direction(X,Y,Z) of the coil and T1, T2 weighted images that used the fast spin echo technique acquired. The ETL with increase of 10 was applied from 10 to 80. In addition, the ETL with increase of 1 was applied in the interval statistically significant differences occurred. And T1, T2 weighted images that used the conventional spin echo technique acquired to compare image blurring of the images that used the fast spin echo technique. The slope of lattice in the images was measured using Image J 1.47v program to evaluate image blurring. And image blurring was determined by the degree of the slope. The statistical significance of both techniques was evaluated by the Kruskal-Wallis test of the SPSS 17.0v. And the correlation of the ETL and image blurring was evaluated quantitatively by regression analysis. The slope of the T1, T2 weighted images that used fast spin echo technique decreased as contrasted with conventional spin echo technique. In the result of the Kruskal-Wallis test, the T1, T2 weighted images that used fast spin echo technique made a significant difference with conventional spin echo technique. Particularly, in the Tomhane' T2 test, the T1, T2 weighted images made a significant difference from ETL 22 and 31 respectively. In the result of the regression analysis, the R-squared of the T1, T2 weighted images are 0.762 and 0.793. It is difficult to apply the long ETL in the T1 weighted image caused by the short TR and multi-slices study. Therefore, clinical impact according to variation of the ETL is very slight in the T1 weighted images. But the application of the proper ETL is demanded in T2 weighted images using the fast spin echo technique in order to prevent image blurring.

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A New Technique or Dual $T_E$ Images Acquisition in Fast Spin Echo MR Imaging (고속 Spin Echo 자기 공명 영상법에서 두 가지 $T_E$ 영상을 얻기 위한 새로운 방법)

  • Cho, M.H.;Lee, S.Y.;Mun, C.W.;Cho, H.H.;Yi, W.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.294-298
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    • 1997
  • In the magnetic resonance imaging, the fast spin echo imaging technique is a widely used clinical imaging method, since its scanning time is much shorter than the conventional spin echo imaging and it gives the almost same image quality. However, the fast spin echo technique has two times longer imaging time or the dual echo acquisition which can obtain a spin density image and a $T_2$-weighted image simultaneously. To overcome such a drawback, this paper proposes a new fast dual echo imaging technique which can give the same quality images at the single echo imaging time. The proposed technique reduces the imaging time by overlapping most of echo train data for each image reconstruction. In order to verify its validity and usability the human head experimental results which were obtained at the 0.3T permanent MRI system are presented.

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A Study on Dynamic Susceptibility-weighted Perfusion MR Imaging at High Magnetic Filed : Comparison of Gradient Echo-EPI and Spin Echo-EPI (고 자장에서 Dynamic Susceptibility Contrast 효과에 관한 연구 : Gradient EPI와 Spin-EPI기법의 비교)

  • Goo, Eun-Hoe;Chae, Hong-In;Park, Jong-Bae;Im, Cheong-Hwan;Kim, Jeong-Koo
    • Korean Journal of Digital Imaging in Medicine
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    • v.9 no.2
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    • pp.11-16
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    • 2007
  • We have evaluated and compared of gradient echo and spin echo EPI for compensating about deeply distortion aspect in case of post-operation patients in magnetic resonance image. A total of 100 patients were performed on 3.0 T(GE Signa Excite E2, USA) with 8ch head coil. As a result of analysis, The SNRs of whiter and gray matter areas were 36.74 $\pm$ 06 and 39.96 $\pm$ 09 in the gradient echo EPI, the SNRs which white and gray matter areas were slightly higher than gradient echo EPI(P<0.005, paired student t-test). It was 46.24 $\pm$ 11 and 51.38 $\pm$ 13 in gradient and spin echo EPI, respectively. The signal intensity in the whiter and gray matter areas also were 87.33 $\pm$ 15.24 and 140.66 $\pm$ 13.45 in the gradient echo EPI techniques, The signal intensity of gradient echo EPI showed higher values compared to spin echo EPI. Otherwise, gradient echo EPI technique is distortion enough to operation wound and edge of the image, while spin echo EPI technique did not appear almost. In this point, the spin echo EPI technique, after surgical operation according to patient state beside gradient echo EPI techniques that signalbeside gradient echo EPI techniques that signal intensity is high and patient's case which image distortion is serious by metal etc, will be provide the useful information in adults and pediatric patients.

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A Study on the Land Cover Classification and Facilities Management of Pusan Port using Satellite data (위성영상을 이용한 부산항만 주변지역 토지피복분류 및 시설물관리 구축 방안)

  • 이기철;김정희;이병환
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.10a
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    • pp.59-65
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    • 1998
  • A thematic land cover map of Pusan port area was developed using Landsat satellite TM(Thematic Mapper) image. Two types of digital data which are road and sea water layer are extracted from existing paper map were overlayed over the developed land cover map. SPIN-2(KNR-1000) image was utilized to make a facility map of JaSungDae port. SPIN-2 image, which has a cell resolution of 1.56 m showed higer accuracy than TM image, which has a cell resolution of 30 m for facility mapping. Overall, the techniques of digital mapping using satellite image are very useful, effective and efficient.

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Cluster-Based Spin Images for Characterizing Diffuse Objects in 3D Range Data

  • Lee, Heezin;Oh, Sangyoon
    • Journal of Sensor Science and Technology
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    • v.23 no.6
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    • pp.377-382
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    • 2014
  • Detecting and segmenting diffuse targets in laser ranging data is a critical problem for tactical reconnaissance. In this study, we propose a new method that facilitates the characterization of diffuse irregularly shaped objects using "spin images," i.e., local 2D histograms of laser returns oriented in 3D space, and a clustering process. The proposed "cluster-based spin imaging" method resolves the problem of using standard spin images for diffuse targets and it eliminates much of the computational complexity that characterizes the production of conventional spin images. The direct processing of pre-segmented laser points, including internal points that penetrate through a diffuse object's topmost surfaces, avoids some of the requirements of the approach used at present for spin image generation, while it also greatly reduces the high computational time overheads incurred by searches to find correlated images. We employed 3D airborne range data over forested terrain to demonstrate the effectiveness of this method in discriminating the different geometric structures of individual tree clusters. Our experiments showed that cluster-based spin images have the potential to separate classes in terms of different ages and portions of tree crowns.

Study on the Characters' Role and Personality Difference in the Series Animation Works (시리즈 애니메이션 캐릭터의 역할과 성격 변화에 대한 고찰)

  • Kong, Hyunhee;Sung, Rea
    • Journal of Information Technology Applications and Management
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    • v.29 no.4
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    • pp.51-60
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    • 2022
  • This study was conducted on characters who play the main character of the spin-off work based on the image in the original. Through the analysis of the original and spin-off works, the role type and characteristics according to the characters' roles were analyzed. It was analyzed that Rex, Bo Peep, and Forky, the main characters of the Toy Story spin-off works, had characteristics described in the original, which were not the main characters, and changed when they appeared in the spin-off works. First, it shows a tendency to add a new personality to play the role of the main character who solves problems and leads the story development while maintaining the existing personality characteristics in the original. Second, in order to play the main character in the spin-off work, these main characters are strongly revealed in the characteristics of the faithful type 6, and the achiever type 3, respectively. The reason why the characters' personality in the existing original have continuity is that if the personality of the existing characters change rapidly, they may contradict the audience's existing perception, preventing them from being immersed in the spin-off protagonist itself and the story development. However, the main characteristics of personality type 6 and personality type 3 are described only by considering the character's role as a helper to solve the problem and the characters' characteristics, but in order to solve the problem in spin-off, the animation producers are determined to achieve the goal. An understanding of this result will greatly help animation producers plan the character in consideration.

Distinction of Internal Tissue of Red Ginseng Using Magnetic Resonance Image (MRI을 이용한 홍삼 내부조직 판별)

  • Kim, Chun-Suk;Jung, In-Chan;Kim, Se-Bong
    • Journal of Ginseng Research
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    • v.32 no.4
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    • pp.332-336
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    • 2008
  • Red ginseng is classified according to outer form and the quality of internal tissue, and red ginseng below third grade can't be sold. Also there are many differences in price according to grade. So if inferior Red ginseng is sold, economic loss and claim take place. This research is done conducted to investigate the possibility of the non-destruction internal tissue investigation of red ginseng. It is observed and compared that MR image after getting MR image agrees with real cutting side in 10-13% water content of red ginseng. The MR image can be obtained to see the internal section of red ginseng with equal condition of time, temperature and slice thickness in spin echo pulse sequence. The MR signal of red ginseng is very weak, because it contains low water density. So it takes about 30 minutes with the measurement of single point image (SPI). But the suitable time to distinguish internal tissues is about 9 seconds in TE (Echo Time) 2.23 ms, TR (Repetition Time) 150ms. The image to discriminate internal tissues in 9 seconds can be obtained when slice thickness is 10 mm with changes of 3, 5, 10 mm. The image obtained after 30 minutes' boiling of 55 degrees has clearer image than that of normal temperature. It is thought that MR signal is stronger through active motion of water particles as temperature increases. With this method MR image of red ginseng can be obtained and characteristics of internal tissues can be observed in such a short time.

Robust 3D Facial Landmark Detection Using Angular Partitioned Spin Images (각 분할 스핀 영상을 사용한 3차원 얼굴 특징점 검출 방법)

  • Kim, Dong-Hyun;Choi, Kang-Sun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.5
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    • pp.199-207
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    • 2013
  • Spin images representing efficiently surface features of 3D mesh models have been used to detect facial landmark points. However, at a certain point, different normal direction can lead to quite different spin images. Moreover, since 3D points are projected to the 2D (${\alpha}-{\beta}$) space during spin image generation, surface features cannot be described clearly. In this paper, we present a method to detect 3D facial landmark using improved spin images by partitioning the search area with respect to angle. By generating sub-spin images for angular partitioned 3D spaces, more unique features describing corresponding surfaces can be obtained, and improve the performance of landmark detection. In order to generate spin images robust to inaccurate surface normal direction, we utilize on averaging surface normal with its neighboring normal vectors. The experimental results show that the proposed method increases the accuracy in landmark detection by about 34% over a conventional method.

Improvement of Gibb's Phenomena in Fast Spin Echo Imaging Using Symmetric Echo Arrangement and Filtering (대칭적 에코 배치 및 필터링을 통한 Fast Spin Echo 영상에서의 Gibb's 현상 개선)

  • 안창범;김치영;오창현;신진교
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.79-85
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    • 1997
  • Fast spin echo imaging utilizes multiple spin echoes to encode multiple k-space lines instead of multiple $T_2-weighted$ images. As results, intensities in k-space data are varying according to T2 decay, which generates Gibb's artifact in the reconstructed image. The echo time for e encoding dc block determines contrast, as is specified by the effective echo time, however, all location of other echoes to different k-space frequency blocks in fast spin echo imaging is not f fully investigated. In this study, symmetric arrangement of multiple echoes in k-space is investigated to reduce Gibb's artifact. Design of filters based on the measurement of multiple e echo intensities is also proposed in two stage manner, i.e., equalization and filtering. From s simulation and experiment, it was observed that Gibb's phenomena were substantially reduced b by the proposed methods.

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