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Journal articles on the topic 'Four-dimensional images'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

RAQUENO, ROLANDO, AMITABHA GHOSH, NAVIN C. NANDA, JOHN SCHOTT, and SALLY MOOS. "Four-Dimensional Reconstruction of Two-Dimensional Echocardiographic Images." Echocardiography 6, no. 4 (July 1989): 323–37. http://dx.doi.org/10.1111/j.1540-8175.1989.tb00312.x.

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2

DOI, TSUKASA. "Three Dimensional and Four Dimensional Images for Help to Application." Japanese Journal of Radiological Technology 58, no. 12 (2002): 1549. http://dx.doi.org/10.6009/jjrt.kj00000921531.

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3

Otton, J., T. Kühl, K. Kofoed, J. McCrohon, M. Feneley, A. Chiribiri, and E. Nagel. "Four-Dimensional (Spatio-Temporal) Image Processing of Myocardial CT-Perfusion Images." Heart, Lung and Circulation 21 (January 2012): S205. http://dx.doi.org/10.1016/j.hlc.2012.05.507.

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Inubashiri, Eisuke, Katumaru Kuroki, Nobuhiko Maeda, Kiichirou Kawai, Noriyuki Akutagawa, Masaki Sugawara, Shosuke Imai, Kunihiro Minami, and Yasuhiro Nomura. "Three-dimensional and four-dimensional HDlive-rendered images of thanatophoric dysplasia." Journal of Medical Ultrasonics 42, no. 2 (November 22, 2014): 281–85. http://dx.doi.org/10.1007/s10396-014-0597-x.

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5

Богоявленская, O. А. "Computing the Minkowskii functionals for four-dimensional digital images." Numerical Methods and Programming (Vychislitel'nye Metody i Programmirovanie), no. 2 (March 19, 2020): 164–71. http://dx.doi.org/10.26089/nummet.v21r214.

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Функционалы Минковского являются важным инструментом для изучения морфологии пористых сред. Настоящая работа посвящена построению алгоритма вычисления функционалов Минковского четырехмерных цифровых изображений, возникающих, в частности, при описании динамики изменения порового пространства среды. В работе впервые программно реализован алгоритм вычисления функционалов Минковского четырехмерных цифровых изображений. The Minkowskii functionals are important for studying the morphology of porous media. This paper is devoted to constructing an algorithm for computing the Minkowskii functionals for four-dimensional digital images used to describe the dynamics of porous media. This algorithm is implemented as a software package.

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Bouilhol, G., M. Ayadi, R. Pinho, S. Rit, and D. Sarrut. "Motion artifact detection in four-dimensional computed tomography images." Journal of Physics: Conference Series 489 (March 24, 2014): 012024. http://dx.doi.org/10.1088/1742-6596/489/1/012024.

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Jufas, N., N. Deveau, and M. Bance. "Dynamic cine imaging of the Eustachian tube using four-dimensional computed tomography." Journal of Laryngology & Otology 130, no. 12 (November 2, 2016): 1162–64. http://dx.doi.org/10.1017/s0022215116009257.

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AbstractBackground:Imaging the Eustachian tube has proven difficult as it has an anatomical orientation that is not aligned with standard planes. In addition, the Eustachian tube is a dynamic structure, opening briefly during a variety of physiological manoeuvres.Case report:A 54-year-old healthy and asymptomatic man underwent computed tomography utilising an area detector scanner. Multiplanar reconstruction was performed at 1 mm intervals. In addition, dynamic clips were constructed to demonstrate air and its movement in the field. Images and video were acquired whilst a Valsalva manoeuvre was being performed.Conclusion:Although imaging techniques have been able to visualise the Eustachian tube well in the closed state, it may be more useful to have it imaged whilst open. Area detector computed tomography scanners can be used to acquire four-dimensional images. This allows dynamic imaging of the region, to assist in the diagnosis of various types of Eustachian tube dysfunction.

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Bae, Joungeun, and Hoon Yoo. "Image Enhancement for Computational Integral Imaging Reconstruction via Four-Dimensional Image Structure." Sensors 20, no. 17 (August 25, 2020): 4795. http://dx.doi.org/10.3390/s20174795.

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This paper describes the image enhancement of a computational integral imaging reconstruction method via reconstructing a four-dimensional (4-D) image structure. A computational reconstruction method for high-resolution three-dimensional (3-D) images is highly required in 3-D applications such as 3-D visualization and 3-D object recognition. To improve the visual quality of reconstructed images, we introduce an adjustable parameter to produce a group of 3-D images from a single elemental image array. The adjustable parameter controls overlapping in back projection with a transformation of cropping and translating elemental images. It turns out that the new parameter is an independent parameter from the reconstruction position to reconstruct a 4-D image structure with four axes of x, y, z, and k. The 4-D image structure of the proposed method provides more visual information than existing methods. Computer simulations and optical experiments are carried out to show the feasibility of the proposed method. The results indicate that our method enhances the image quality of 3-D images by providing a 4-D image structure with the adjustable parameter.

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Hwang, Jinwoo, June Sic Kim, Jae Seok Kim, In Young Kim, and Sun I. Kim. "Real-time volume rendering of four-dimensional images based on three-dimensional texture mapping." Journal of Digital Imaging 14, S1 (June 2001): 202–4. http://dx.doi.org/10.1007/bf03190339.

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10

Nastar, C., and N. Ayache. "Frequency-based nonrigid motion analysis: application to four dimensional medical images." IEEE Transactions on Pattern Analysis and Machine Intelligence 18, no. 11 (1996): 1067–79. http://dx.doi.org/10.1109/34.544076.

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11

Wang, Jing, and Xuejun Gu. "High-quality four-dimensional cone-beam CT by deforming prior images." Physics in Medicine and Biology 58, no. 2 (December 21, 2012): 231–46. http://dx.doi.org/10.1088/0031-9155/58/2/231.

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Yamamoto, Tokihiro, Sven Kabus, Tobias Klinder, Jens von Berg, Cristian Lorenz, Billy W. Loo, and Paul J. Keall. "Four-dimensional computed tomography pulmonary ventilation images vary with deformable image registration algorithms and metrics." Medical Physics 38, no. 3 (February 16, 2011): 1348–58. http://dx.doi.org/10.1118/1.3547719.

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Shakir, Huda R., Sadiq A. Mehdi, and Anwar A. Hattab. "A new four-dimensional hyper-chaotic system for image encryption." International Journal of Electrical and Computer Engineering (IJECE) 13, no. 2 (April 1, 2023): 1744. http://dx.doi.org/10.11591/ijece.v13i2.pp1744-1756.

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<span lang="EN-US">Currently, images are very important with the rapid growth of communication networks. Therefore, image encryption is a process to provide security for private information and prevent unwanted access to sensitive data by unauthorized individuals. Chaos systems provide an important role for key generation, with high randomization properties and accurate performance. In this study, a new four-dimensional hyper-chaotic system has been suggested that is used in the keys generation, which are utilized in the image encryption process to achieve permutation and substitution operations. Firstly, color bands are permuted using the index of the chaotic sequences to remove the high correlation among neighboring pixels. Secondly, dynamic S-boxes achieve the principle of substitution, which are utilized to diffuse the pixel values of the color image. The efficiency of the proposed method is tested by the key space, histogram, and so on. Security analysis shows that the proposed method for encrypting images is secure and resistant to different attacks. It contains a big key space of (2627) and a high sensitivity to a slight change in the secret key, a fairly uniform histogram, and entropy values nearby to the best value of 8. Moreover, it consumes a very short time for encryption and decryption.</span>

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Zeng, Rongping, Jeffrey A. Fessler, James M. Balter, and Peter A. Balter. "Iterative sorting for four-dimensional CT images based on internal anatomy motion." Medical Physics 35, no. 3 (February 15, 2008): 917–26. http://dx.doi.org/10.1118/1.2837286.

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Bashar, Md Khayrul, Kazuo Yamagata, and Tetsuya J. Kobayashi. "Improved and Robust Detection of Cell Nuclei from Four Dimensional Fluorescence Images." PLoS ONE 9, no. 7 (July 14, 2014): e101891. http://dx.doi.org/10.1371/journal.pone.0101891.

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Marshall, Wallace, David Agard, and John Sedat. "An algorithm for estimation of chromosome motion in Four-Dimensional microscopic images." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 930–31. http://dx.doi.org/10.1017/s0424820100172383.

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Analysis of the three-dimensional organization of chromosomes within the nucleus has revealed a number of characteristic structural features. Yet imaging of living nuclei indicate that chromosomes undergo considerable random motion. Maintenance of nuclear organization in the face of such motion is thought to involve the attachment of chromosomes to the nuclear envelope or matrix. Yet while such attachments have been proposed to play a variety of functional roles as well as maintain nuclear organization, direct evidence for the existence of these mechanical interactions in vivo has been lacking. One way to demonstrate such attachment directly would be to estimate the motion of chromosomes and attempt thereby to demonstrate the presence of fixed points, which would indicate attachment of chromatin to some fixed superstructure.We have previously presented a motion estimation algorithm that is designed for tracking the motion of nonrigid and featureless objects such as chromosomes. This algorithm starts with a structural representation for the set of chromosomes at each time point, and then finds a correspondence between elements of the representations at successive time points.

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Johnson, Ryan K., Senthil Premraj, Sonali S. Patel, Nicholas Walker, Andreas Wahle, Milan Sonka, and Thomas D. Scholz. "Automated analysis of four-dimensional magnetic resonance images of the human aorta." International Journal of Cardiovascular Imaging 26, no. 5 (February 10, 2010): 571–78. http://dx.doi.org/10.1007/s10554-010-9592-5.

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18

Gooding, M. J., K. Rajpoot, S. Mitchell, P. Chamberlain, J. A. Noble, and S. H. Kennedy. "OC18.01: Fusion of multiple four dimensional fetal echocardiography images can improve quality." Ultrasound in Obstetrics & Gynecology 34, S1 (September 2009): 34. http://dx.doi.org/10.1002/uog.6562.

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19

Bolbakov, R. G., V. A. Mordvinov, and A. D. Makarevich. "Comparative analysis of compression algorithms for four-dimensional light fields." Russian Technological Journal 10, no. 4 (July 29, 2022): 7–17. http://dx.doi.org/10.32362/2500-316x-2022-10-4-7-17.

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Objectives. The widespread use of systems for capturing light fields is due to the high quality of the reproduced image. This type of capture, although qualitatively superior to traditional methods to capturing volumetric images, generates a huge amount of data needed to reconstruct the original captured 4D light field. The purpose of the work is to consider traditional and extended to four-dimensional image compression algorithms, to perform a comparative analysis and determine the most suitable.Methods. Mathematical methods of signal processing and methods of statistical analysis are used.Results. Algorithms are compared and analyzed in relation to the compression of four-dimensional light fields using the PSNR metric. The selected evaluation criterion is affected not only by the dimension of the compression algorithm, but also by the distance of the baseline of the capture setting, since the difference between images increases with the distance between the optical centers of each camera matrix. Thus, for installations consisting of an array of machine vision cameras located on racks and placed in a room, the obvious choice would be to use conventional image compression methods. Furthermore, based on the assessment of the arbitrariness of video compression methods, it should be noted that the XVC algorithm remains undervalued, although its results are higher. Algorithm AV1 can be considered the next in order of importance. It has been established that the latest compression algorithms show higher performance if compared to their predecessors. It has also been shown that with a small distance between the optical centers of the captured images, the use of video compression algorithms is preferable to the use of image compression algorithms, since they show better results in both three-dimensional and four-dimensional versions.Conclusions. A comparison of the results obtained shows the need to use algorithms from the video compression family (XVC, AV1) on installations with a long baseline (mounted on camera stands). When working with integrated light field cameras (Lytro) and setting the capture with a short baseline, it is recommended to use image compression algorithms (JPEG). In general, video compression algorithms are recommended, in particular XVC, since on average it shows an acceptable level of PSNR in both the case of a short and long installation baseline.

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20

Liu, Xiaoping. "Computer-aided recognition of a four-chamber image plane in three-dimensional echocardiographic images of children." Journal of Electronic Imaging 17, no. 3 (July 1, 2008): 030502. http://dx.doi.org/10.1117/1.2956009.

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21

Tonetto, Mateus Samuel, Hugo Goulart de Oliveira, Andre Frotta Muller, Paulo Roberto Stefani Sanches, Luciano Folador, Felipe Soares Torres, and Tiago Severo Garcia. "Development of a customized three-dimensional airway model." Research, Society and Development 11, no. 9 (July 20, 2022): e33111931721. http://dx.doi.org/10.33448/rsd-v11i9.31721.

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This study aimed to develop a customized, three-dimensional airway model based on relevant medical images, using additive manufacturing techniques. We evaluated the model’s ability to replicate the dimensions of the images acquired from the chest of a patient using multi-detector computed tomography (CT). Using dedicated software, a three-dimensional mesh was created based on the images. A multi-detector CT study of the full-scale printed three-dimensional airways model was subsequently carried out to compare its dimensions with that of the original study at four predetermined points. The observed median differences at the four points were 0.4 mm (p = 0.686), -1.3 mm (p = 0.138), 0.7 mm (p = 0.141), and 0.1 mm (p = 0.892). The intraclass correlation coefficient between the measurements made on the patient and those on the model was 0.98 (95% confidence interval: 0.96–0.99, p < 0.001). We successfully developed a three-dimensional model of the airway based on its corresponding medical images. The differences in the dimensions between the model and the original images were in line with those observed in previous studies and are presumably irrelevant for most applications.

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Chalif, David J., Craig R. Dufresne, Joseph Ransohoff, and Joseph A. McCarthy. "Three-Dimensional Computed Tomographic Reconstructions of Intracranial Meningiomas." Neurosurgery 23, no. 5 (November 1, 1988): 570–75. http://dx.doi.org/10.1227/00006123-198811000-00005.

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Abstract In a series of four patients with intracranial meningiomas, three-dimensional computed tomographic (CT) reconstructions were a useful diagnostic and surgical adjunct. Three-dimensional images are created from standard CT data by a boundary-detecting computer software program. Three-dimensional images of tumor invading or adjacent to the bony calvarium are projected about the x, y, and z axes. Axial and sagittal sections delineate the lesions. The images created allow a surgical view of the meningiomas in three-dimensional space and demonstrate the relationship of these masses to the skull. The use of three-dimensional reconstructions in craniofacial surgery and in neurosurgery is reviewed.

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23

Morrison, H. Boyd. "Depth and Image Quality of Three-Dimensional, Lenticular-Sheet Images." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 41, no. 2 (October 1997): 1338–42. http://dx.doi.org/10.1177/1071181397041002135.

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This study investigated the inherent tradeoff between depth and image quality in lenticular-sheet (LS) imaging. Four different scenes were generated as experimental stimuli to represent a range of typical LS images. The overall amount of depth in each image, as well as the degree of foreground and background disparity, were varied, and the images were rated by subjects using the free-modulus magnitude estimation procedure. Generally, subjects preferred images which had smaller amounts of overall depth and tended to dislike excessive amounts of foreground or background disparity. The most preferred image was also determined for each scene by selecting the image with the highest mean rating. In a second experiment, these most preferred LS images for each scene were shown to subjects along with the analogous two-dimensional (2D) photographic versions. Results indicate that observers from the general population looked at the LS images longer than they did at the 2D versions and rated them higher on the attributes of quality of depth and attention-getting ability, although the LS images were rated lower on sharpness. No difference was found in overall quality or likeability.

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Rincón, Manuel García, Diego Mendez, and Julian D. Colorado. "Four-Dimensional Plant Phenotyping Model Integrating Low-Density LiDAR Data and Multispectral Images." Remote Sensing 14, no. 2 (January 13, 2022): 356. http://dx.doi.org/10.3390/rs14020356.

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High-throughput platforms for plant phenotyping usually demand expensive high-density LiDAR devices with computational intense methods for characterizing several morphological variables. In fact, most platforms require offline processing to achieve a comprehensive plant architecture model. In this paper, we propose a low-cost plant phenotyping system based on the sensory fusion of low-density LiDAR data with multispectral imagery. Our contribution is twofold: (i) an integrated phenotyping platform with embedded processing methods capable of providing real-time morphological data, and (ii) a multi-sensor fusion algorithm that precisely match the 3D LiDAR point-cloud data with the corresponding multispectral information, aiming for the consolidation of four-dimensional plant models. We conducted extensive experimental tests over two plants with different morphological structures, demonstrating the potential of the proposed solution for enabling real-time plant architecture modeling in the field, based on low-density LiDARs.

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Chen, Bing, Yong Hu, Jin Liu, An-Ning Cao, Lu-Xi Ye, and Zhao-Chong Zeng. "Respiratory motion of adrenal gland metastases: Analyses using four-dimensional computed tomography images." Physica Medica 38 (June 2017): 54–58. http://dx.doi.org/10.1016/j.ejmp.2017.05.045.

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Li, Xutong, Taoying Li, and Yan Wang. "GW-DC: A Deep Clustering Model Leveraging Two-Dimensional Image Transformation and Enhancement." Algorithms 14, no. 12 (November 29, 2021): 349. http://dx.doi.org/10.3390/a14120349.

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Traditional time-series clustering methods usually perform poorly on high-dimensional data. However, image clustering using deep learning methods can complete image annotation and searches in large image databases well. Therefore, this study aimed to propose a deep clustering model named GW_DC to convert one-dimensional time-series into two-dimensional images and improve cluster performance for algorithm users. The proposed GW_DC consisted of three processing stages: the image conversion stage, image enhancement stage, and image clustering stage. In the image conversion stage, the time series were converted into four kinds of two-dimensional images by different algorithms, including grayscale images, recurrence plot images, Markov transition field images, and Gramian Angular Difference Field images; this last one was considered to be the best by comparison. In the image enhancement stage, the signal components of two-dimensional images were extracted and processed by wavelet transform to denoise and enhance texture features. Meanwhile, a deep clustering network, combining convolutional neural networks with K-Means, was designed for well-learning characteristics and clustering according to the aforementioned enhanced images. Finally, six UCR datasets were adopted to assess the performance of models. The results showed that the proposed GW_DC model provided better results.

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Hirano, Yasushi, Akinobu Shimizu, Jun-ichi Hasegawa, and Jun-ichiro Toriwaki. "A tracking algorithm for extracting ridge lines in three-dimensional gray images using curvature of four-dimensional hypersurface." Systems and Computers in Japan 32, no. 12 (November 15, 2001): 25–37. http://dx.doi.org/10.1002/scj.1075.

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Coléou, Cécile, Bernard Lesaffre, Jean-Bruno Brzoska, Wolfgang Ludwig, and Elodie Boller. "Three-dimensional snow images by X-ray microtomography." Annals of Glaciology 32 (2001): 75–81. http://dx.doi.org/10.3189/172756401781819418.

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AbstractFor the first time, three-dimensional (3-D) high-resolution images of snow were obtained using X-ray absorption tomography. Images with a spatial resolution of 10 μm were taken on four different cylindrical snow samples (9 mm high, 9 mm diameter). About 1000 two-dimensional X-ray absorption images were recorded at angular positions of the object around an axis spanning 180°. An appropriate algorithm was then used for these data to reconstruct a 3-D image. In the case of snow, experimental problems have been solved to prepare the samples and prevent both melting and metamorphism of snow during the experiments. This tomographic method provided 3-D data files from which images of 6003 voxels were extracted Several physical parameters of snow microstructure can be processed from these data. Porosity P and discrete local (3-D) curvature C of the grain/pore interface were computed for the four snow samples. Representative elementary volume (REV, in the sense of porous media) is a relevant index to the significance of the sample size with respect to a given parameter. From each image, the values of P and C are compared for subsamples of different size, as an attempt to assess the REVs for porosity and curvature. Results show that the observed volume of snow is statistically significant to achieve the porosity and the curvature distribution.

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Petrov, Nikolai, Maksim Khromov, and Yuri Sokolov. "Multi-View 3D Integral Imaging Systems Using Projectors and Mobile Devices." Photonics 8, no. 8 (August 13, 2021): 331. http://dx.doi.org/10.3390/photonics8080331.

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Glassless 3D displays using projectors and mobile phones based on integral imaging technology have been developed. Three-dimensional image files are created from the 2D images captured by a conventional camera. Large size 3D images using four HD and Ultra HD 4K projectors are created with a viewing angle of 35 degrees and a large depth. Three-dimensional images are demonstrated using optimized lenticular lenses and mobile smartphones, such as LG and Samsung with resolution 2560 × 1440, and 4K Sony with resolution 3840 × 2160.

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Cui, Guoqiang, Brian Jew, Julian C. Hong, Eric W. Johnston, Billy W. Loo, and Peter G. Maxim. "An automated method for comparing motion artifacts in cine four-dimensional computed tomography images." Journal of Applied Clinical Medical Physics 13, no. 6 (November 2012): 170–80. http://dx.doi.org/10.1120/jacmp.v13i6.3838.

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Schreibmann, E., B. Thorndyke, and L. Xing. "TU-C-ValA-07: Intra- and Inter-Modality Registration of Four-Dimensional (4D) Images." Medical Physics 33, no. 6Part16 (June 2006): 2187. http://dx.doi.org/10.1118/1.2241512.

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Ozturk, Cengizhan, and Elliot R. McVeigh. "Four-dimensional B-spline based motion analysis of tagged MR images: introduction andin vivovalidation." Physics in Medicine and Biology 45, no. 6 (May 19, 2000): 1683–702. http://dx.doi.org/10.1088/0031-9155/45/6/319.

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Shekhar, Raj, Vladimir Zagrodsky, Carlos R. Castro-Pareja, Vivek Walimbe, and Jogikal M. Jagadeesh. "High-Speed Registration of Three- and Four-dimensional Medical Images by Using Voxel Similarity." RadioGraphics 23, no. 6 (November 2003): 1673–81. http://dx.doi.org/10.1148/rg.236035041.

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Hata, Toshiyuki, Uiko Hanaoka, Chiaki Tenkumo, Miki Sato, Hirokazu Tanaka, and Mari Ishimura. "Three- and four-dimensional HDlive rendering images of normal and abnormal fetuses: pictorial essay." Archives of Gynecology and Obstetrics 286, no. 6 (August 7, 2012): 1431–35. http://dx.doi.org/10.1007/s00404-012-2505-1.

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35

Comas, C., G. Azumendi, I. Alonso, J. R. Herrero, M. Romero, J. Anderica, A. Calvo, I. Narbona, F. Rius, and R. Hidalgo. "P09.15: Three- and four-dimensional ultrasound: when and how to obtain the best images?" Ultrasound in Obstetrics and Gynecology 28, no. 4 (August 31, 2006): 579. http://dx.doi.org/10.1002/uog.3654.

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Bidnichenko, Helena. "FOUR-DIMENSIONAL BALL IN A GRAPHIC REPRESENTATION." APPLIED GEOMETRY AND ENGINEERING GRAPHICS, no. 100 (May 24, 2021): 37–46. http://dx.doi.org/10.32347/0131-579x.2021.100.37-46.

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The paper presents a method for geometric modelling of a four-dimensional ball. For this, the regularities of the change in the shape of the projections of simple geometric images of two-dimensional and three-dimensional spaces during rotation are considered. Rotations of a segment and a circle around an axis are considered; it is shown that during rotation the shape of their projections changes from the maximum value to the degenerate projection. It was found that the set of points of the degenerate projection belongs to the axis of rotation, and each n-dimensional geometric image during rotation forms a body of a higher dimension, that is, one that belongs to (n + 1) -dimensional space. Identified regularities are extended to the four-dimensional space in which the ball is placed. It is shown that the axis of rotation of the ball will be a degenerate projection in the form of a circle, and the ball, when rotating, changes its size from a volumetric object to a flat circle, then increases again, but in the other direction (that is, it turns out), and then in reverse order to its original position. This rotation is more like a deformation, and such a ball of four-dimensional space is a hypersphere. For geometric modelling of the hypersphere and the possibility of its projection image, the article uses the vector model proposed by P.V. Filippov. The coordinate system 0xyzt is defined. The algebraic equation of the hypersphere is given by analogy with the three-dimensional space along certain coordinates of the center a, b, c, d. A variant of hypersection at t = 0 is considered, which confirms by equations obtaining a two-dimensional ball of three-dimensional space, a point (a ball of zero radius), which coincides with the center of the ball, or an imaginary ball. For the variant t = d, the equation of a two-dimensional ball is obtained, in which the radius is equal to R and the coordinates of all points along the 0t axis are equal to d. The variant of hypersection t = k turned out to be interesting, in which the equation of a two-dimensional sphere was obtained, in which the coordinates of all points along the 0t axis are equal to k, and the radius is . Horizontal vector projections of hypersection are constructed for different values of k. It is concluded that the set of horizontal vector projections of hypersections at t = k defines an ellipse.

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Wang, Jiang Wei. "An Improved Three-Dimensional Medical Image Segmentation Approach." Advanced Materials Research 912-914 (April 2014): 1150–55. http://dx.doi.org/10.4028/www.scientific.net/amr.912-914.1150.

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This paper presents an three-dimensional medical image segmentation approach based on Live-Wire algorithm, through the virtual slices extraction to transform the direction of the segmentation from parallel direction into meridian direction, the amount of user interaction is independent of the number of the sequence of medicine images, improves the automation level of medicine images segmentation. This paper also improved the efficiency of traditional Live-Wire algorithm by four binary heap. Experiment shows that the approach can segmented the interest objects from the sequence of medical images rapidly and accurately, with less user interaction.

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Левкин and Yu Levkin. "Obtaining of Four-Dimensional Nomograms Based on Similarity Theorem." Geometry & Graphics 5, no. 2 (July 4, 2017): 69–74. http://dx.doi.org/10.12737/article_5953f334279642.78930109.

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In some performed experimental works there is no total characteristic of study processes with regard to their physical understanding. It’s possible to achieve such understanding by means of epure and graphic interdependency for parameters illustrating experiment process, and by means of geometrical images which testify regularity of their outline, and are characteristic of physical process. The use of epure multidimensional octant nomogram can promote the solution for a number of application-oriented problems. By means of two octant epure nomograms constructed on experimental tabular data with four or five parameters, the optimum choice of graphic execution and its implementation in the area of physical genesis is offered. This method’s justifications have been given in the paper. A basis for extension of new opportunities is certainly descriptive geometry that facilitates a solution to technical tasks on multidimensional geometry. At the heart of similarity of adjacent octant cells with general axis are plotted two octant axonometric nomograms creating interdependencies between parameters by means of communication lines. This method opens a possibility for physical processes’ nature understanding. In this paper have been presented two graphic models for two octant nomograms in which advantages of their creation and reading have been presented. Foundations on which derivations are built when constructing the nomograms are validated by the similarity theorem and the axiom of projected surface. Absolute values of parameters are actual ones, and presented from papers of journals, as well as from peer-reviewed scientific publications recommended by Higher Attestation Commission.

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Wang, Jing, Yu Zhang, Yushi Zhang, Lin Zhang*, Xiaojie Pan, and Qinghua Zhao. "Clinical Diagnostic Value of Two-Dimensional and Four-Dimensional Echocardiography in Fetal Cardiac Tumor." Tobacco Regulatory Science 7, no. 5 (September 30, 2021): 1271–78. http://dx.doi.org/10.18001/trs.7.5.44.

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This paper aims to investigate the clinical diagnostic value of two-dimensional and four-dimensional echocardiography in fetal cardiac tumor. Material and Methods: A total of 24 pregnant women whose fetus had suspected cardiac tumor in The No.4 Hospital 1946 Jinan Shandong from February 2011 to April 2018 were selected as objects of study, including 18 cases whose fetus was pathologically diagnosed with fetal cardiac tumor (+) and 6 cases whose fetus was diagnosed with fetal cardiac tumor (−). Results:These patients were retrospectively analyzed. The tumor site, size, activity and fetal edema predicted using two-dimensional and four-dimensional ultrasound images were compared with pathological examination results, and the diagnostic value of the two kinds of echocardiography in fetal cardiac tumor was analyzed. The echocardiographic results revealed that there were no statistically significant differences in the four-dimensional ultrasonic diagnosis and two-dimensional ultrasonic diagnosis results compared with pathological diagnosis results (p>0.05). In terms of the diagnostic value, the sensitivity, specificity and diagnostic accordance rate in the clinical diagnosis of fetal cardiac tumor were 66.67%, 50.00% and 62.5%, respectively, in two-dimensional echocardiography, and 94.44%, 83.33% and 91.67%, respectively, in four-dimensional echocardiography. Conclusions: Echocardiography can determine the activity, shape, site, size, etc., of primary cardiac tumor. Two-dimensional and four-dimensional ultrasonic diagnosis can be used to observe the fetal cardiac tumor, thus making an early diagnosis. The sensitivity, specificity and diagnostic accordance rate of four-dimensional echocardiography in the clinical diagnosis of fetal cardiac tumor are significantly higher than those of two-dimensional echocardiography, so four-dimensional echocardiography has higher diagnostic value in fetal cardiac tumor.

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Wang, Xiaowei, Shoulin Yin, Muhammad Shafiq, Asif Ali Laghari, Shahid Karim, Omar Cheikhrouhou, Wajdi Alhakami, and Habib Hamam. "A New V-Net Convolutional Neural Network Based on Four-Dimensional Hyperchaotic System for Medical Image Encryption." Security and Communication Networks 2022 (February 14, 2022): 1–14. http://dx.doi.org/10.1155/2022/4260804.

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In the transmission of medical images, if the image is not processed, it is very likely to leak data and personal privacy, resulting in unpredictable consequences. Traditional encryption algorithms have limited ability to deal with complex data. The chaotic system is characterized by randomness and ergodicity, which has advantages over traditional encryption algorithms in image encryption processing. A novel V-net convolutional neural network (CNN) based on four-dimensional hyperchaotic system for medical image encryption is presented in this study. Firstly, the plaintext medical images are processed into 4D hyperchaotic sequence images, including image segmentation, chaotic system processing, and pseudorandom sequence generation. Then, V-net CNN is used to train chaotic sequences to eliminate the periodicity of chaotic sequences. Finally, the chaotic sequence image is diffused to change the raw image pixel to realize the encryption processing. Simulation test analysis demonstrates that the proposed algorithm has better effect, robustness, and plaintext sensitivity.

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Fews, A. P., M. J. Lamb, and M. Savage. "Three-dimensional α-particle imaging of laser-driven implosions." Laser and Particle Beams 12, no. 1 (March 1994): 1–11. http://dx.doi.org/10.1017/s0263034600007187.

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A technique is demonstrated for optimally generating three-dimensional reconstructions of images formed using a minimal quantity of data. The results are illustrated using thermonuclear α-particles from laser-driven implosions. The images are generated with a maximum entropy deconvolution algorithm from sets of three or four penumbral imaging cameras. It is demonstrated that this approach provides superior resolution and reveals structures not visible from the corresponding two-dimensional reconstructions of the constituent data. This technique can be successfully applied even when the total number of particles recorded in the image is less than 1000.

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Sugiura, Takako, Yuka Sato, Naoyuki Nakanami, and Kiyomi Tsukimori. "Prenatal Sonographic Image of Sirenomelia with Anencephaly and Craniorachischisis Totalis." Case Reports in Obstetrics and Gynecology 2018 (November 28, 2018): 1–5. http://dx.doi.org/10.1155/2018/7058253.

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Sirenomelia is a rare congenital malformation characterized by varying degrees of fusion of the lower extremities. It is commonly associated with severe urogenital and gastrointestinal malformations; however, the association of sirenomelia with anencephaly and rachischisis totalis is extremely rare. To our knowledge, the prenatal sonographic images of this association have not been previously published. Here, we present prenatal sonographic images of this association, detected during the 17th week of gestation through combined two-dimensional, four-dimensional, and color Doppler ultrasound. Two-dimensional ultrasound images showed anencephaly, spina bifida, and possible fusion of the lower limbs. Three-dimensional HDlive rendering images confirmed the final diagnosis of sirenomelia with anencephaly and rachischisis totalis. The patient opted to undergo medical termination of pregnancy and delivered a fetus with fused lower limbs, anencephaly, and rachischisis totalis confirming the in utero imaging findings. Awareness of these rare associations will help avoid misdiagnoses and facilitate prenatal counselling. This case highlights the importance of a thorough ultrasound examination.

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Mori, Takahisa, Toshimitsu Shimizu, Hirobumi Sato, and Natsuki Mashikawa. "Cut-Out Towne-View Whole-Brain 320-Row Four-Dimensional Computed Tomography Angiography for Assessing the Anterior Intracranial Collateral Status: A Retrospective Study." Diagnostics 12, no. 6 (May 27, 2022): 1336. http://dx.doi.org/10.3390/diagnostics12061336.

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Whole-brain four-dimensional computed tomography angiography (W4D-CTA) using a 320-row area detector CT (320r-ADCT) has been applied before thrombectomy. Endovascular physicians require images with high interrater reliability (IRR) for making appropriate decisions. However, the 320r-ADCT gantry cannot be tilted, and the patient’s head position influences the anteroposterior (AP)-view W4D-CTA images. This study aimed to determine which W4D-CTA images are appropriate pre-thrombectomy, whether the unedited AP view or cut-out Towne view. This study included the W4D-CTA images of acute stroke patients with occlusion of the internal carotid artery or the middle cerebral artery (MCA) from April to July 2021. Images produced by 320r-ADCT were transferred to a workstation. Unedited AP-view images were automatically generated. Towne-view images were cut out for this study. Collateral status was evaluated as poor, intermediate, or good based on the visualization of the MCA peripheral branches. In addition, the IRR was assessed using intraclass correlation coefficients (ICC) (2,1). Fifteen patients were analyzed. In the unedited AP-view and cut-out Towne-view W4D-CTA images, the ICC (2,1) were 0.147 and 0.796, respectively. Cut-out Towne-view W4D-CTA images with substantial IRR are superior to the unedited AP-view images for assessing the anterior intracranial collateral status.

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Rajeswari, R., and R. Rajesh. "On the Efficient Compression of fMRI Data Series of Brain." Neuroradiology Journal 21, no. 6 (December 2008): 737–43. http://dx.doi.org/10.1177/197140090802100601.

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Four dimensional medical images, namely fMRI, require a large volume of memory to store the data. Compression techniques are therefore used for the storage and transmission of these medical images. This paper proposes a coding scheme for volumetric images which in the first stage recognizes significant images and in the second stage compresses those images using a JPEG-LS coding scheme. An example implementation for 4D fMRI data series of brain stored in ANALYZE file format is illustrated in this paper. The proposed scheme provides efficient compression for 4D fMRI medical images.

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Li, Hongtong, Ivana Ivankovic, Jiao Li, Daniel Razansky, and Xosé Luís Deán-Ben. "Coregistration and Spatial Compounding of Optoacoustic Cardiac Images via Fourier Analysis of Four-Dimensional Data." Applied Sciences 10, no. 18 (September 9, 2020): 6254. http://dx.doi.org/10.3390/app10186254.

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Volumetric optoacoustic tomography has been shown to provide unprecedented capabilities for ultrafast imaging of cardiovascular dynamics in mice. Three-dimensional imaging rates in the order of 100 Hz have been achieved, which enabled the visualization of transient cardiac events such as arrhythmias or contrast agent perfusion without the need for retrospective gating. The fast murine heart rates (400–600 beats per minute) yet impose limitations when it comes to compounding of multiple frames or accurate registration of multi-spectral data. Herein, we investigate on the capabilities of Fourier analysis of four-dimensional data for coregistration of independent volumetric optoacoustic image sequences of the heart. The fundamental frequencies and higher harmonics of respiratory and cardiac cycles could clearly be distinguished, which facilitated efficient retrospective gating without additional readings. The performance of the suggested methodology was successfully demonstrated by compounding cardiac images acquired by raster-scanning of a spherical transducer array as well as by unmixing of oxygenated and deoxygenated hemoglobin from multi-spectral optoacoustic data.

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Yamamoto, T., U. Langner, and P. J. Keall. "Analysis of Artifacts in Four-dimensional CT Images of 50 Abdominal and Thoracic Radiotherapy Patients." International Journal of Radiation Oncology*Biology*Physics 72, no. 1 (September 2008): S610. http://dx.doi.org/10.1016/j.ijrobp.2008.06.239.

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Wang, W., J. Li, Q. Shao, Y. Zhang, S. Liu, and M. Xu. "Comparison of the Planning Target Volume Based on Three-Dimensional CT and Four-Dimensional CT Images of Thoracic Esophageal Cancer." International Journal of Radiation Oncology*Biology*Physics 93, no. 3 (November 2015): E161—E162. http://dx.doi.org/10.1016/j.ijrobp.2015.07.962.

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Shkryl, Vyacheslav M., Lothar A. Blatter, and Eduardo Ríos. "Properties of Ca2+ sparks revealed by four-dimensional confocal imaging of cardiac muscle." Journal of General Physiology 139, no. 3 (February 13, 2012): 189–207. http://dx.doi.org/10.1085/jgp.201110709.

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Parameters (amplitude, width, kinetics) of Ca2+ sparks imaged confocally are affected by errors when the spark source is not in focus. To identify sparks that were in focus, we used fast scanning (LSM 5 LIVE; Carl Zeiss) combined with fast piezoelectric focusing to acquire x–y images in three planes at 1-µm separation (x-y-z-t mode). In 3,000 x–y scans in each of 34 membrane-permeabilized cat atrial cardiomyocytes, 6,906 sparks were detected. 767 sparks were in focus. They had greater amplitude, but their spatial width and rise time were similar compared with all sparks recorded. Their distribution of amplitudes had a mode at ΔF/F0 = 0.7. The Ca2+ release current underlying in-focus sparks was 11 pA, requiring 20 to 30 open channels, a number at the high end of earlier estimates. Spark frequency was greater than in earlier imaging studies of permeabilized ventricular cells, suggesting a greater susceptibility to excitation, which could have functional relevance for atrial cells. Ca2+ release flux peaked earlier than the time of peak fluorescence and then decayed, consistent with significant sarcoplasmic reticulum (SR) depletion. The evolution of fluorescence and release flux were strikingly similar for in-focus sparks of different rise time (T). Spark termination involves both depletion of Ca2+ in the SR and channel closure, which may be synchronized by depletion. The observation of similar flux in sparks of different T requires either that channel closure and other termination processes be independent of the determinants of flux (including [Ca2+]SR) or that different channel clusters respond to [Ca2+]SR with different sensitivity.

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Wang, He, Sunil Krishnan, Xiaochun Wang, A. Sam Beddar, Tina M. Briere, Christopher H. Crane, Radhe Mohan, and Lei Dong. "Improving Soft-Tissue Contrast in Four-Dimensional Computed Tomography Images of Liver Cancer Patients Using a Deformable Image Registration Method." International Journal of Radiation Oncology*Biology*Physics 72, no. 1 (September 2008): 201–9. http://dx.doi.org/10.1016/j.ijrobp.2008.04.054.

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Wang, He, Adam S. Garden, Lifei Zhang, Xiong Wei, Anesa Ahamad, Deborah A. Kuban, Ritsuko Komaki, et al. "Performance Evaluation of Automatic Anatomy Segmentation Algorithm on Repeat or Four-Dimensional Computed Tomography Images Using Deformable Image Registration Method." International Journal of Radiation Oncology*Biology*Physics 72, no. 1 (September 2008): 210–19. http://dx.doi.org/10.1016/j.ijrobp.2008.05.008.

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