- tomography [tə mäg′rə fē]n.a process for producing an image of a single plane of an object excluding all other planes, as by using CT SCAN or ULTRASOUND, in diagnostic medicine, seismic surveys, etc.
* * *to·mog·ra·phy (tō-mŏgʹrə-fē) n.Any of several techniques for making detailed x-rays of a predetermined plane section of a solid object while blurring out the images of other planes.[Greek tomos, section; see tome + -graphy.] toʹmo·gram' (tōʹmə-grăm') n. toʹmo·graph' (-grăf') n. to'mo·graphʹic adj.
* * *IRadiological technique for obtaining clear X-ray images of internal structures by focusing on a specific plane within the body to produce a cross-sectional image.It allows the examination of structures that are obscured by overlying organs and soft tissues and do not show up clearly on conventional X-ray images. See also computed axial tomography.II(as used in expressions)computed axial tomographycomputed tomography
* * *radiologic technique for obtaining clear X-ray images of deep internal structures by focusing on a specific plane within the body. Structures that are obscured by overlying organs and soft tissues that are insufficiently delineated on conventional X rays can thus be adequately visualized.The simplest method is linear tomography, in which the X-ray tube is moved in a straight line in one direction while the film moves in the opposite direction. As these shifts occur, the X-ray tube continues to emit radiation so that most structures in the part of the body under examination are blurred by motion. Only those objects lying in a plane coinciding with the pivot point of a line between the tube and the film are in focus. A somewhat more complicated technique known as multidirectional tomography produces an even sharper image by moving the film and X-ray tube in a circular or elliptical pattern. As long as both tube and film move in synchrony, a clear image of objects in the focal plane can be produced. These tomographic approaches have been used to study the kidneys and other abdominal structures that are surrounded by tissues of nearly the same density and so cannot be differentiated by conventional X-ray techniques. They have also been employed to examine the small bones and other structures of the ear, which are surrounded by relatively dense temporal bone.A still more complex technique, variously called computerized tomography (computer) (CT), or computerized axial tomography (CAT), was developed by Godfrey Hounsfield of Great Britain and Allen Cormack of the United States during the early 1970s. Since then it has become a widely used diagnostic approach. In this procedure a narrow beam of X rays sweeps across an area of the body and is recorded not on film but by a radiation detector as a pattern of electrical impulses. Data from many such sweeps are integrated by a computer, which uses the radiation absorption figures to assess the density of tissues at thousands of points. The density values appear on a television-like screen as points of varying brightness to produce a detailed cross-sectional image of the internal structure under scrutiny. See also diagnostic imaging; radiology.
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tomography — (n.) 1935, from Gk. tomos slice, section (see TOME (Cf. tome)) + GRAPHY (Cf. graphy) … Etymology dictionary
tomography — [tə mäg′rə fē] n. [< Gr tomos, a piece cut off (see TOMY) + GRAPHY] a process for producing an image of a single plane of an object excluding all other planes, as by using CT SCAN or ULTRASOUND, in diagnostic medicine, seismic surveys, etc … English World dictionary
Tomography — Basic principle of tomography: superposition free tomographic cross sections S1 and S2 compared with the projected image P Tomography refers to imaging by sections or sectioning, through the use of any kind of penetrating wave. A device used in… … Wikipedia
tomography — Making of a radiographic image of a selected plane by means of reciprocal linear or curved motion of the x ray tube and film cassette; images of all other planes are blurred (“out of focus”) by being relatively displaced on the film. SYN:… … Medical dictionary
tomography — n. the technique of rotating a radiation detector around the patient so that the image obtained gives additional three dimensional information. In plain film tomography the source of X rays and the photographic film move round the patient to… … The new mediacal dictionary
tomography — noun Etymology: Greek tomos section + International Scientific Vocabulary graphy more at tome Date: 1935 a method of producing a three dimensional image of the internal structures of a solid object (as the human body or the earth) by the… … New Collegiate Dictionary
tomography — noun Imaging by sections or sectioning. See Also: tomogram, computed tomography … Wiktionary
tomography — tomografija statusas T sritis Standartizacija ir metrologija apibrėžtis Tiriamo erdvinio objekto sluoksnių vaizdų gavimas. atitikmenys: angl. laminography; tomography vok. Körperschichtaufnahmeverfahren, n; Laminographie, f;… … Penkiakalbis aiškinamasis metrologijos terminų žodynas
tomography — tomografija statusas T sritis chemija apibrėžtis Tyrimo metodų, leidžiančių pasluoksniui tyrinėti objekto sandarą, visuma. atitikmenys: angl. body section radiography; laminography; planigraphy; tomography rus. томография … Chemijos terminų aiškinamasis žodynas
tomography — tomografija statusas T sritis fizika atitikmenys: angl. body section roentgenography; laminography; tomography vok. Röntgenschichtaufnahmeverfahren, n; Röntgenschichtverfahren, n; Tomographie, f rus. послойная рентгенография, f; томография, f… … Fizikos terminų žodynas