Fig.1: Basic principle of tomography: superposition free tomographic cross sections S1 and S2 compared with the (not tomographic) projected image PMedian planesagittal tomography of the head by magnetic resonance imaging.
In many cases, the production of these images is based on the mathematical procedure tomographic reconstruction, such as X-ray computed tomography technically being produced from multiple projectional radiographs. Many different reconstruction algorithms exist. Most algorithms fall into one of two categories: filtered back projection (FBP) and iterative reconstruction (IR). These procedures give inexact results: they represent a compromise between accuracy and computation time required. FBP demands fewer computational resources, while IR generally produces fewer artifacts (errors in the reconstruction) at a higher computing cost.[1]
Although MRI (magnetic resonance imaging), Optical coherence tomography and ultrasound are transmission methods, they typically do not require movement of the transmitter to acquire data from different directions. In MRI, both projections and higher spatial harmonics are sampled by applying spatially-varying magnetic fields; no moving parts are necessary to generate an image. On the other hand, since ultrasound and optical coherence tomography uses time-of-flight to spatially encode the received signal, it is not strictly a tomographic method and does not require multiple image acquisitions.
Some recent advances rely on using simultaneously integrated physical phenomena, e.g. X-rays for both CT and angiography, combined CT/MRI and combined CT/PET.
Discrete tomography and Geometric tomography, on the other hand, are research areas[citation needed] that deal with the reconstruction of objects that are discrete (such as crystals) or homogeneous. They are concerned with reconstruction methods, and as such they are not restricted to any of the particular (experimental) tomography methods listed above.
Synchrotron X-ray tomographic microscopyEdit
A new technique called synchrotron X-ray tomographic microscopy (SRXTM) allows for detailed three-dimensional scanning of fossils.[14][15]
The construction of third-generation synchrotron sources combined with the tremendous improvement of detector technology, data storage and processing capabilities since the 1990s has led to a boost of high-end synchrotron tomography in materials research with a wide range of different applications, e.g. the visualization and quantitative analysis of differently absorbing phases, microporosities, cracks, precipitates or grains in a specimen. Synchrotron radiation is created by accelerating free particles in high vacuum. By the laws of electrodynamics this acceleration leads to the emission of electromagnetic radiation (Jackson, 1975). Linear particle acceleration is one possibility, but apart from the very high electric fields one would need it is more practical to hold the charged particles on a closed trajectory in order to obtain a source of continuous radiation. Magnetic fields are used to force the particles onto the desired orbit and prevent them from flying in a straight line. The radial acceleration associated with the change of direction then generates radiation.[16]
Volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampleddata set, typically a 3D scalar field. A typical 3D data set is a group of 2D slice images acquired, for example, by a CT, MRI, or MicroCTscanner. These are usually acquired in a regular pattern (e.g., one slice every millimeter) and usually have a regular number of image pixels in a regular pattern. This is an example of a regular volumetric grid, with each volume element, or voxel represented by a single value that is obtained by sampling the immediate area surrounding the voxel.
To render a 2D projection of the 3D data set, one first needs to define a camera in space relative to the volume. Also, one needs to define the opacity and color of every voxel. This is usually defined using an RGBA (for red, green, blue, alpha) transfer function that defines the RGBA value for every possible voxel value.
For example, a volume may be viewed by extracting isosurfaces (surfaces of equal values) from the volume and rendering them as polygonal meshes or by rendering the volume directly as a block of data. The marching cubes algorithm is a common technique for extracting an isosurface from volume data. Direct volume rendering is a computationally intensive task that may be performed in several ways.
HistoryEdit
Focal plane tomography was developed in the 1930s by the radiologist Alessandro Vallebona, and proved useful in reducing the problem of superimposition of structures in projectional radiography.
In a 1953 article in the medical journal Chest, B. Pollak of the Fort William Sanatorium described the use of planography, another term for tomography.[17]
Focal plane tomography remained the conventional form of tomography until being largely replaced by mainly computed tomography in the late-1970s.[18] Focal plane tomography uses the fact that the focal plane appears sharper, while structures in other planes appear blurred. By moving an X-ray source and the film in opposite directions during the exposure, and modifying the direction and extent of the movement, operators can select different focal planes which contain the structures of interest.
^Herman, Gabor T. (2009). Fundamentals of Computerized Tomography: Image Reconstruction from Projections (2nd ed.). Dordrecht: Springer. ISBN978-1-84628-723-7.
^Micheva, Kristina D.; Smith, Stephen J (July 2007). "Array Tomography: A New Tool for Imaging the Molecular Architecture and Ultrastructure of Neural Circuits". Neuron. 55 (1): 25–36. doi:10.1016/j.neuron.2007.06.014. PMC2080672. PMID 17610815.
^Ford, Bridget K.; Volin, Curtis E.; Murphy, Sean M.; Lynch, Ronald M.; Descour, Michael R. (February 2001). "Computed Tomography-Based Spectral Imaging For Fluorescence Microscopy". Biophysical Journal. 80 (2): 986–993. Bibcode:2001BpJ....80..986F. doi:10.1016/S0006-3495(01)76077-8. PMC1301296. PMID 11159465.
^Floyd, J.; Geipel, P.; Kempf, A.M. (February 2011). "Computed Tomography of Chemiluminescence (CTC): Instantaneous 3D measurements and Phantom studies of a turbulent opposed jet flame". Combustion and Flame. 158 (2): 376–391. doi:10.1016/j.combustflame.2010.09.006.
^Mohri, K; Görs, S; Schöler, J; Rittler, A; Dreier, T; Schulz, C; Kempf, A (10 September 2017). "Instantaneous 3D imaging of highly turbulent flames using computed tomography of chemiluminescence". Applied Optics. 56 (26): 7385–7395. Bibcode:2017ApOpt..56.7385M. doi:10.1364/AO.56.007385. PMID 29048060.
^Huang, S M; Plaskowski, A; Xie, C G; Beck, M S (1988). "Capacitance-based tomographic flow imaging system". Electronics Letters. 24 (7): 418–19. Bibcode:1988ElL....24..418H. doi:10.1049/el:19880283.
^Crowther, R. A.; DeRosier, D. J.; Klug, A.; S, F. R. (1970-06-23). "The reconstruction of a three-dimensional structure from projections and its application to electron microscopy". Proc. R. Soc. Lond. A. 317 (1530): 319–340. Bibcode:1970RSPSA.317..319C. doi:10.1098/rspa.1970.0119. ISSN 0080-4630. S2CID 122980366.
^Electron tomography: methods for three-dimensional visualization of structures in the cell (2nd ed.). New York: Springer. 2006. pp. 3. ISBN9780387690087. OCLC 262685610.
^Martin, Michael C; Dabat-Blondeau, Charlotte; Unger, Miriam; Sedlmair, Julia; Parkinson, Dilworth Y; Bechtel, Hans A; Illman, Barbara; Castro, Jonathan M; Keiluweit, Marco; Buschke, David; Ogle, Brenda; Nasse, Michael J; Hirschmugl, Carol J (September 2013). "3D spectral imaging with synchrotron Fourier transform infrared spectro-microtomography". Nature Methods. 10 (9): 861–864. doi:10.1038/nmeth.2596. PMID 23913258. S2CID 9900276.
^Cramer, A., Hecla, J., Wu, D. et al. Stationary Computed Tomography for Space and other Resource-constrained Environments. Sci Rep 8, 14195 (2018). [1]
^ V. B. Neculaes, P. M. Edic, M. Frontera, A. Caiafa, G. Wang and B. De Man, "Multisource X-Ray and CT: Lessons Learned and Future Outlook," in IEEE Access, vol. 2, pp. 1568-1585, 2014, doi: 10.1109/ACCESS.2014.2363949.[2]
^Ahadi, Mojtaba; Isa, Maryam; Saripan, M. Iqbal; Hasan, W. Z. W. (December 2015). "Three dimensions localization of tumors in confocal microwave imaging for breast cancer detection" (PDF). Microwave and Optical Technology Letters. 57 (12): 2917–2929. doi:10.1002/mop.29470. S2CID 122576324.
^Puschnig, P.; Berkebile, S.; Fleming, A. J.; Koller, G.; Emtsev, K.; Seyller, T.; Riley, J. D.; Ambrosch-Draxl, C.; Netzer, F. P.; Ramsey, M. G. (30 October 2009). "Reconstruction of Molecular Orbital Densities from Photoemission Data". Science. 326 (5953): 702–706. Bibcode:2009Sci...326..702P. doi:10.1126/science.1176105. PMID 19745118. S2CID 5476218.
^"Contributors to Volume 21". Metals, Microbes, and Minerals - the Biogeochemical Side of Life. De Gruyter. 2021. pp. xix–xxii. doi:10.1515/9783110589771-004. ISBN9783110588903. S2CID 243434346.
^Banhart, John, ed. Advanced Tomographic Methods in Materials Research and Engineering. Monographs on the Physics and Chemistry of Materials. Oxford ; New York: Oxford University Press, 2008.
^Pollak, B. (December 1953). "Experiences with Planography". Chest. 24 (6): 663–669. doi:10.1378/chest.24.6.663. ISSN 0012-3692. PMID 13107564. Archived from the original on 2013-04-14. Retrieved July 10, 2011.
^Littleton, J.T. "Conventional Tomography" (PDF). A History of the Radiological Sciences. American Roentgen Ray Society. Retrieved 29 November 2014.
External linksEdit
Media related to Tomography at Wikimedia Commons
Image reconstruction algorithms for microtomography
October 14, 2023
tomography, imaging, sections, sectioning, that, uses, kind, penetrating, wave, method, used, radiology, archaeology, biology, atmospheric, science, geophysics, oceanography, plasma, physics, materials, science, astrophysics, quantum, information, other, areas. Tomography is imaging by sections or sectioning that uses any kind of penetrating wave The method is used in radiology archaeology biology atmospheric science geophysics oceanography plasma physics materials science astrophysics quantum information and other areas of science The word tomography is derived from Ancient Greek tomos tomos slice section and grafw graphō to write or in this context as well to describe A device used in tomography is called a tomograph while the image produced is a tomogram Fig 1 Basic principle of tomography superposition free tomographic cross sections S1 and S2 compared with the not tomographic projected image PMedian plane sagittal tomography of the head by magnetic resonance imaging In many cases the production of these images is based on the mathematical procedure tomographic reconstruction such as X ray computed tomography technically being produced from multiple projectional radiographs Many different reconstruction algorithms exist Most algorithms fall into one of two categories filtered back projection FBP and iterative reconstruction IR These procedures give inexact results they represent a compromise between accuracy and computation time required FBP demands fewer computational resources while IR generally produces fewer artifacts errors in the reconstruction at a higher computing cost 1 Although MRI magnetic resonance imaging Optical coherence tomography and ultrasound are transmission methods they typically do not require movement of the transmitter to acquire data from different directions In MRI both projections and higher spatial harmonics are sampled by applying spatially varying magnetic fields no moving parts are necessary to generate an image On the other hand since ultrasound and optical coherence tomography uses time of flight to spatially encode the received signal it is not strictly a tomographic method and does not require multiple image acquisitions Contents 1 Types of tomography 1 1 Synchrotron X ray tomographic microscopy 2 Volume rendering 3 History 4 See also 5 References 6 External linksTypes of tomography EditName Source of data Abbreviation Year of introductionAerial tomography Electromagnetic radiation AT 2020Array tomography 2 Correlative light and electron microscopy AT 2007Atom probe tomography Atom probe APTComputed tomography imaging spectrometer 3 Visible light spectral imaging CTIS 2001Computed tomography of chemiluminescence 4 5 Chemiluminescence Flames CTC 2009Confocal microscopy Laser scanning confocal microscopy Laser scanning confocal microscopy LSCMCryogenic electron tomography Cryogenic transmission electron microscopy CryoETElectrical capacitance tomography Electrical capacitance ECT 1988 6 Electrical capacitance volume tomography Electrical capacitance ECVTElectrical resistivity tomography Electrical resistivity ERTElectrical impedance tomography Electrical impedance EIT 1984Electron tomography Transmission electron microscopy ET 1968 7 8 Focal plane tomography X ray 1930sFunctional magnetic resonance imaging Magnetic resonance fMRI 1992Gamma ray emission tomography Tomographic Gamma Scanning Gamma ray TGS or ECTGamma ray transmission tomography Gamma ray TCTHydraulic tomography fluid flow HT 2000Infrared microtomographic imaging 9 Mid infrared 2013Laser Ablation Tomography Laser Ablation amp Fluorescent Microscopy LAT 2013Magnetic induction tomography Magnetic induction MITMagnetic particle imaging Superparamagnetism MPI 2005Magnetic resonance imaging or nuclear magnetic resonance tomography Nuclear magnetic moment MRI or MRTMulti source tomography 10 11 X rayMuon tomography MuonMicrowave tomography 12 MicrowaveNeutron tomography NeutronNeutron stimulated emission computed tomographyOcean acoustic tomography Sonar OATOptical coherence tomography Interferometry OCTOptical diffusion tomography Absorption of light ODTOptical projection tomography Optical microscope OPTPhotoacoustic imaging in biomedicine Photoacoustic spectroscopy PATPhotoemission Orbital Tomography Angle resolved photoemission spectroscopy POT 2009 13 Positron emission tomography Positron emission PETPositron emission tomography computed tomography Positron emission amp X ray PET CTQuantum tomography Quantum state QSTSingle photon emission computed tomography Gamma ray SPECTSeismic tomography Seismic wavesTerahertz tomography Terahertz radiation THz CTThermoacoustic imaging Photoacoustic spectroscopy TATUltrasound modulated optical tomography Ultrasound UOTUltrasound computer tomography Ultrasound USCTUltrasound transmission tomography UltrasoundX ray computed tomography X ray CT CATScan 1971X ray microtomography X ray microCTZeeman Doppler imaging Zeeman effectSome recent advances rely on using simultaneously integrated physical phenomena e g X rays for both CT and angiography combined CT MRI and combined CT PET Discrete tomography and Geometric tomography on the other hand are research areas citation needed that deal with the reconstruction of objects that are discrete such as crystals or homogeneous They are concerned with reconstruction methods and as such they are not restricted to any of the particular experimental tomography methods listed above Synchrotron X ray tomographic microscopy Edit A new technique called synchrotron X ray tomographic microscopy SRXTM allows for detailed three dimensional scanning of fossils 14 15 The construction of third generation synchrotron sources combined with the tremendous improvement of detector technology data storage and processing capabilities since the 1990s has led to a boost of high end synchrotron tomography in materials research with a wide range of different applications e g the visualization and quantitative analysis of differently absorbing phases microporosities cracks precipitates or grains in a specimen Synchrotron radiation is created by accelerating free particles in high vacuum By the laws of electrodynamics this acceleration leads to the emission of electromagnetic radiation Jackson 1975 Linear particle acceleration is one possibility but apart from the very high electric fields one would need it is more practical to hold the charged particles on a closed trajectory in order to obtain a source of continuous radiation Magnetic fields are used to force the particles onto the desired orbit and prevent them from flying in a straight line The radial acceleration associated with the change of direction then generates radiation 16 Volume rendering EditMain article Volume rendering nbsp Multiple X ray computed tomographs with quantitative mineral density calibration stacked to form a 3D model Volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampled data set typically a 3D scalar field A typical 3D data set is a group of 2D slice images acquired for example by a CT MRI or MicroCT scanner These are usually acquired in a regular pattern e g one slice every millimeter and usually have a regular number of image pixels in a regular pattern This is an example of a regular volumetric grid with each volume element or voxel represented by a single value that is obtained by sampling the immediate area surrounding the voxel To render a 2D projection of the 3D data set one first needs to define a camera in space relative to the volume Also one needs to define the opacity and color of every voxel This is usually defined using an RGBA for red green blue alpha transfer function that defines the RGBA value for every possible voxel value For example a volume may be viewed by extracting isosurfaces surfaces of equal values from the volume and rendering them as polygonal meshes or by rendering the volume directly as a block of data The marching cubes algorithm is a common technique for extracting an isosurface from volume data Direct volume rendering is a computationally intensive task that may be performed in several ways History EditFocal plane tomography was developed in the 1930s by the radiologist Alessandro Vallebona and proved useful in reducing the problem of superimposition of structures in projectional radiography In a 1953 article in the medical journal Chest B Pollak of the Fort William Sanatorium described the use of planography another term for tomography 17 Focal plane tomography remained the conventional form of tomography until being largely replaced by mainly computed tomography in the late 1970s 18 Focal plane tomography uses the fact that the focal plane appears sharper while structures in other planes appear blurred By moving an X ray source and the film in opposite directions during the exposure and modifying the direction and extent of the movement operators can select different focal planes which contain the structures of interest See also EditChemical imaging 3D reconstruction Discrete tomography Geometric tomography Geophysical imaging Industrial CT scanning Johann Radon Medical imaging MRI compared with CT Network tomography Nonogram a type of puzzle based on a discrete model of tomography Radon transform Tomographic reconstruction Multiscale Tomography VoxelsReferences Edit Herman Gabor T 2009 Fundamentals of Computerized Tomography Image Reconstruction from Projections 2nd ed Dordrecht Springer ISBN 978 1 84628 723 7 Micheva Kristina D Smith Stephen J July 2007 Array Tomography A New Tool for Imaging the Molecular Architecture and Ultrastructure of Neural Circuits Neuron 55 1 25 36 doi 10 1016 j neuron 2007 06 014 PMC 2080672 PMID 17610815 Ford Bridget K Volin Curtis E Murphy Sean M Lynch Ronald M Descour Michael R February 2001 Computed Tomography Based Spectral Imaging For Fluorescence Microscopy Biophysical Journal 80 2 986 993 Bibcode 2001BpJ 80 986F doi 10 1016 S0006 3495 01 76077 8 PMC 1301296 PMID 11159465 Floyd J Geipel P Kempf A M February 2011 Computed Tomography of Chemiluminescence CTC Instantaneous 3D measurements and Phantom studies of a turbulent opposed jet flame Combustion and Flame 158 2 376 391 doi 10 1016 j combustflame 2010 09 006 Mohri K Gors S Scholer J Rittler A Dreier T Schulz C Kempf A 10 September 2017 Instantaneous 3D imaging of highly turbulent flames using computed tomography of chemiluminescence Applied Optics 56 26 7385 7395 Bibcode 2017ApOpt 56 7385M doi 10 1364 AO 56 007385 PMID 29048060 Huang S M Plaskowski A Xie C G Beck M S 1988 Capacitance based tomographic flow imaging system Electronics Letters 24 7 418 19 Bibcode 1988ElL 24 418H doi 10 1049 el 19880283 Crowther R A DeRosier D J Klug A S F R 1970 06 23 The reconstruction of a three dimensional structure from projections and its application to electron microscopy Proc R Soc Lond A 317 1530 319 340 Bibcode 1970RSPSA 317 319C doi 10 1098 rspa 1970 0119 ISSN 0080 4630 S2CID 122980366 Electron tomography methods for three dimensional visualization of structures in the cell 2nd ed New York Springer 2006 pp 3 ISBN 9780387690087 OCLC 262685610 Martin Michael C Dabat Blondeau Charlotte Unger Miriam Sedlmair Julia Parkinson Dilworth Y Bechtel Hans A Illman Barbara Castro Jonathan M Keiluweit Marco Buschke David Ogle Brenda Nasse Michael J Hirschmugl Carol J September 2013 3D spectral imaging with synchrotron Fourier transform infrared spectro microtomography Nature Methods 10 9 861 864 doi 10 1038 nmeth 2596 PMID 23913258 S2CID 9900276 Cramer A Hecla J Wu D et al Stationary Computed Tomography for Space and other Resource constrained Environments Sci Rep 8 14195 2018 1 V B Neculaes P M Edic M Frontera A Caiafa G Wang and B De Man Multisource X Ray and CT Lessons Learned and Future Outlook in IEEE Access vol 2 pp 1568 1585 2014 doi 10 1109 ACCESS 2014 2363949 2 Ahadi Mojtaba Isa Maryam Saripan M Iqbal Hasan W Z W December 2015 Three dimensions localization of tumors in confocal microwave imaging for breast cancer detection PDF Microwave and Optical Technology Letters 57 12 2917 2929 doi 10 1002 mop 29470 S2CID 122576324 Puschnig P Berkebile S Fleming A J Koller G Emtsev K Seyller T Riley J D Ambrosch Draxl C Netzer F P Ramsey M G 30 October 2009 Reconstruction of Molecular Orbital Densities from Photoemission Data Science 326 5953 702 706 Bibcode 2009Sci 326 702P doi 10 1126 science 1176105 PMID 19745118 S2CID 5476218 Donoghue PC Bengtson S Dong XP Gostling NJ Huldtgren T Cunningham JA Yin C Yue Z Peng F Stampanoni M 10 August 2006 Synchrotron X ray tomographic microscopy of fossil embryos Nature 442 7103 680 3 Bibcode 2006Natur 442 680D doi 10 1038 nature04890 PMID 16900198 S2CID 4411929 Contributors to Volume 21 Metals Microbes and Minerals the Biogeochemical Side of Life De Gruyter 2021 pp xix xxii doi 10 1515 9783110589771 004 ISBN 9783110588903 S2CID 243434346 Banhart John ed Advanced Tomographic Methods in Materials Research and Engineering Monographs on the Physics and Chemistry of Materials Oxford New York Oxford University Press 2008 Pollak B December 1953 Experiences with Planography Chest 24 6 663 669 doi 10 1378 chest 24 6 663 ISSN 0012 3692 PMID 13107564 Archived from the original on 2013 04 14 Retrieved July 10 2011 Littleton J T Conventional Tomography PDF A History of the Radiological Sciences American Roentgen Ray Society Retrieved 29 November 2014 External links Edit nbsp Media related to Tomography at Wikimedia Commons Image reconstruction algorithms for microtomography Retrieved from https en wikipedia org w index php title Tomography amp oldid 1157943447, wikipedia, wiki, book, books, library,
