• 제목/요약/키워드: three-dimensional imaging

검색결과 696건 처리시간 0.029초

관상동맥질환에서 심장 하이브리드 영상의 임상적 이용 (Clinical Application of Cardiac Hybrid Imaging in Coronary Artery Disease)

  • 조인호;공은정
    • Journal of Yeungnam Medical Science
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    • 제26권1호
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    • pp.15-23
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    • 2009
  • Constant technological developments in coronary artery disease have contributed to the assessment of both the presence of coronary stenosis and its hemodynamic consequences. Hence, noninvasive imaging helps guide therapeutic decisions by providing complementary information on coronary morphology and on myocardial perfusion and metabolism. This can he done using single photon emission computed tomography (SPECT) or positron emission tomography (PET) and multidetector CT (MDCT). Advances in image-processing software and the advent of SPECT/CT and PET/CT have paved the way for the combination of image datasets from different modalities, giving rise to hybrid imaging. Three dimensional cardiac hybrid imaging helped to confirm hemodynamic significance in many lesions, add new lesions such as left main coronay artery disease, exclude equivocal defects, correct the corresponding arteries to their allocated defects and identify culprit segment. Cardiac hybrid imaging avoids the mental integration of functional and morphologic images and facilitates a comprehensive interpretation of coronaty lesions and their pathophysiologic adequacy by three dimensional display of fused images, and allows the best evaluation of myocardial territories and the coronary-artery branches that serve each territory. This integration of functional and morphological information were feasible to intuitively convincing and might facilitate development of a comprehensive non-invasive assessment of coronary artery disease.

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Feasibility of Three-Dimensional Balanced Steady-State Free Precession Cine Magnetic Resonance Imaging Combined with an Image Denoising Technique to Evaluate Cardiac Function in Children with Repaired Tetralogy of Fallot

  • YaFeng Peng;XinYu Su;LiWei Hu;Qian Wang;RongZhen Ouyang;AiMin Sun;Chen Guo;XiaoFen Yao;Yong Zhang;LiJia Wang;YuMin Zhong
    • Korean Journal of Radiology
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    • 제22권9호
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    • pp.1525-1536
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    • 2021
  • Objective: To investigate the feasibility of cine three-dimensional (3D) balanced steady-state free precession (b-SSFP) imaging combined with a non-local means (NLM) algorithm for image denoising in evaluating cardiac function in children with repaired tetralogy of Fallot (rTOF). Materials and Methods: Thirty-five patients with rTOF (mean age, 12 years; range, 7-18 years) were enrolled to undergo cardiac cine image acquisition, including two-dimensional (2D) b-SSFP, 3D b-SSFP, and 3D b-SSFP combined with NLM. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) of the two ventricles were measured and indexed by body surface index. Acquisition time and image quality were recorded and compared among the three imaging sequences. Results: 3D b-SSFP with denoising vs. 2D b-SSFP had high correlation coefficients for EDV, ESV, SV, and EF of the left (0.959-0.991; p < 0.001) as well as right (0.755-0.965; p < 0.001) ventricular metrics. The image acquisition time ± standard deviation (SD) was 25.1 ± 2.4 seconds for 3D b-SSFP compared with 277.6 ± 0.7 seconds for 2D b-SSFP, indicating a significantly shorter time with the 3D than the 2D sequence (p < 0.001). Image quality score was better with 3D b-SSFP combined with denoising than with 3D b-SSFP (mean ± SD, 3.8 ± 0.6 vs. 3.5 ± 0.6; p = 0.005). Signal-to-noise ratios for blood and myocardium as well as contrast between blood and myocardium were higher for 3D b-SSFP combined with denoising than for 3D b-SSFP (p < 0.05 for all but septal myocardium). Conclusion: The 3D b-SSFP sequence can significantly reduce acquisition time compared to the 2D b-SSFP sequence for cine imaging in the evaluation of ventricular function in children with rTOF, and its quality can be further improved by combining it with an NLM denoising method.

Crosstalk evaluation in multiview autostereoscopic three-dimensional displays with an optimized diaphragm applied

  • Peng, Yi-Fan;Li, Hai-Feng;Zheng, Zhen-Rong;Xia, Xin-Xing;Yao, Zhi;Liu, Xu
    • Journal of Information Display
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    • 제13권2호
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    • pp.83-89
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    • 2012
  • The crosstalk evaluation of multiview autostereoscopic three-dimensional (3D) displays is discussed, with both the human and technical factors investigated via image quality assessment. In the imaging performance measurements and analysis for a multiview autostereoscopic display prototype equipment, it was inferred that crosstalk would have both a positive and a negative effect on the imaging performance of the equipment. The importance of the attached diaphragm in the crosstalk evaluation was proposed and then experimentally verified, using the developed prototype equipment. The luminance distribution and crosstalk situation were given, with two different diaphragm arrays applied. The analysis results showed that the imaging performance of this 3D display system can be improved with minimum changes to the system structure.

단일카메라 전방향 스테레오 비전 시스템을 이용한 거리측정 (Depth Measurement using an Omnidirectional Stereo Vision System with a Single Camera)

  • 이수영;김순철
    • 제어로봇시스템학회논문지
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    • 제19권11호
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    • pp.955-959
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    • 2013
  • It is possible to obtain an omnidirectional stereo image via a single camera by using a catadioptric approach with a convex mirror and concave lens. In order to measure three-dimensional distance using the imaging system, the optical parameters of the system are required. In this paper, a calibration procedure to extract the parameters of the imaging system is described. Based on the parameters, experiments are carried out to verify the performance of the three-dimensional distance measurement of a single camera omnidirectional stereo imaging system.

자기공명영상 림프관조영술 (MR Lymphangiography)

  • 이상훈;홍준표
    • 대한영상의학회지
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    • 제81권1호
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    • pp.70-80
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    • 2020
  • 림프부종의 수술적 치료는 최근 늘어나고 있으며 그에 따른 림프관 평가를 위해 자기공명영상 획득이 증가하고 있다. 전통적인 T2 강조영상에서부터 삼차원 영상에 이르기까지 많은 발전이 이루어지고 있는 분야이다. 삼차원 영상으로는 spoiled gradient echo 영상이 있고 그 변형기법들이 시행되고 있으며 영상에 필수적인 지방억제기법은 최근 mDixon 기법이 각광받고 있다.

Development of a virtual studio system for live broadcasting of election results: VdreamSet

  • Ko, Hee-Dong;Kim, Hyun-Suk;Kim, Lae-Hyun;Ahn, Jae-Hong;Park, Kyung-Dong
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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    • pp.213.1-218
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    • 1999
  • A virtual studio is a new video production environment using interactive computer graphics and imaging media technology. The traditional chroma-keying with two-dimensional background is replaced by an advanced keying method with a dynamic computer-generated, three-dimensional background. We have developed a virtual studio system that is practical to use in the real production environment. It has not only essential features that are common among various commercial virtual studio systems, but also unique feature that help the producer to construct virtual studio sets and scenarios efficiently such as span graph, robust backup controller, and 3 dimensional character generator supporting all languages. Our virtual studio system was used in live broadcasting and proved that the system was practical enough. In this paper, we will introduce the structure and the major features of our system, called VdreamSet, and application examples to broadcasting.

Identification of ginseng root using quantitative X-ray microtomography

  • Ye, Linlin;Xue, Yanling;Wang, Yudan;Qi, Juncheng;Xiao, Tiqiao
    • Journal of Ginseng Research
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    • 제41권3호
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    • pp.290-297
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    • 2017
  • Background: The use of X-ray phase-contrast microtomography for the investigation of Chinese medicinal materials is advantageous for its nondestructive, in situ, and three-dimensional quantitative imaging properties. Methods: The X-ray phase-contrast microtomography quantitative imaging method was used to investigate the microstructure of ginseng, and the phase-retrieval method is also employed to process the experimental data. Four different ginseng samples were collected and investigated; these were classified according to their species, production area, and sample growth pattern. Results: The quantitative internal characteristic microstructures of ginseng were extracted successfully. The size and position distributions of the calcium oxalate cluster crystals (COCCs), important secondary metabolites that accumulate in ginseng, are revealed by the three-dimensional quantitative imaging method. The volume and amount of the COCCs in different species of the ginseng are obtained by a quantitative analysis of the three-dimensional microstructures, which shows obvious difference among the four species of ginseng. Conclusion: This study is the first to provide evidence of the distribution characteristics of COCCs to identify four types of ginseng, with regard to species authentication and age identification, by X-ray phase-contrast microtomography quantitative imaging. This method is also expected to reveal important relationships between COCCs and the occurrence of the effective medicinal components of ginseng.

Late reconstruction of extensive orbital floor fracture with a patient-specific implant in a bombing victim

  • Smeets, Maximiliaan;Snel, Robin;Sun, Yi;Dormaar, Titiaan;Politis, Constantinus
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제46권5호
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    • pp.353-357
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    • 2020
  • Fractures of the orbital floor and walls are among the most frequent maxillofacial fractures. Virtual three-dimensional (3D) planning and use of patient-specific implants (PSIs) could improve anatomic and functional outcomes in orbital reconstruction surgery. The presented case was a victim of a terrorist attack involving improvised explosive devices. This 58-year-old female suffered severe wounds caused by a single piece of metal from a bomb, shattering the left orbital floor and lateral orbital wall. Due to remaining hypotropia of the left eye compared to the right eye, late orbital floor reconstruction was carried out with a personalised 3D printed titanium implant. We concluded that this technique with PSI appears to be a viable method to correct complex orbital floor defects. Our research group noted good aesthetic and functional results one year after surgery. Due to the complexity of the surgery for a major bony defect of the orbital floor, it is important that the surgery be executed by experienced surgeons in the field of maxillofacial traumatology.

Terahertz Nondestructive Time-of-flight Imaging with a Large Depth Range

  • Kim, Hwan Sik;Kim, Jangsun;Ahn, Yeong Hwan
    • Current Optics and Photonics
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    • 제6권6호
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    • pp.619-626
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    • 2022
  • In this study, we develop a three-dimensional (3D) terahertz time-of-flight (THz-TOF) imaging technique with a large depth range, based on asynchronous optical sampling (ASOPS) methods. THz-TOF imaging with the ASOPS technique enables rapid scanning with a time-delay span of 10 ns. This means that a depth range of 1.5 m is possible in principle, whereas in practice it is limited by the focus depth determined by the optical geometry, such as the focal length of the scan lens. We characterize the spatial resolution of objects at different vertical positions with a focal length of 5 cm. The lateral resolution varies from 0.8-1.8 mm within the vertical range of 50 mm. We obtain THz-TOF images for samples with multiple reflection layers; the horizontal and vertical locations of the objects are successfully determined from the 2D cross-sectional images, or from reconstructed 3D images. For instance, we can identify metallic objects embedded in insulating enclosures having a vertical depth range greater than 30 mm. For feasible practical use, we employ the proposed technique to locate a metallic object within a thick chocolate bar, which is not accessible via conventional transmission geometry.

상부기도병변의 평가에 있어 나선식컴퓨터단층촬영술을 이용한 3차원적 영상의 유용성 (The Usefulness of Three-Dimensional Imaging with Spiral CT for Evaluation of the Upper Airway Lesions)

  • 김진환;김현웅;소상훈;노영수;임현준;윤대영
    • 대한기관식도과학회지
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    • 제4권1호
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    • pp.43-51
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    • 1998
  • Background: Three-dementional imaging with spiral CT(3D spiral CT) is a well established imaging modality which has been investigated in various clinical settings. However the 3D spiral CT in upper airway disease is rarely reported and its results are still obscure. Objectives: To access the usefulness of 3D spiral CT imaging in patients with upper airway diseases. Materials and Methods We performed 3D spiral CT in fourteen patients In whom upper airway diseases were clinically suspected. Nine of these patients had upper airway stenosis, two had laryngeal cartilage fracture, and three had laryngo-hypopharyngeal cancer. For evaluation of location and extent of the lesions, we compared the findings of 3D imaging with those of air tracheogram, conventional 2D CT images, endoscopic and operative findings. Results: In case of stenosis, 3D spiral CT provide significant useful information, particularly the site and length of the stenotic segment. But, it was difficult to define the fracture of the laryngeal framework and to detect the cartilagenous invasion by head and neck cancer using the 3D imaging. Conclusion : The 3D spiral CT was an useful adjunctive method to assess some kind of upper airway disease but not in others. So, we should compare the findings of 3D images with those of other diagnostic tools for accurate diagnosis of the upper airway disease.

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