| image | <microscopy> A representation of an object produced by means of radiation usually with a lens or mirror system. (05 Aug 1998) |
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| image amplifier | A device for converting a low light level fluoroscopic image to one that can be seen by the eye in a lighted environment; usually consists of an electronic light amplifier chained to a television tube. Synonym: image intensifier. (05 Mar 2000) |
| image cytometry | A technique encompassing morphometry, densitometry, neural networks, and expert systems that has numerous clinical and research applications and is particularly useful in anatomic pathology for the study of malignant lesions. The most common current application of image cytometry is for DNA analysis, followed by quantitation of immunohistochemical staining. (12 Dec 1998) |
| image enhancement | Improvement of the quality of a picture by various techniques, including computer processing, digital filtering, echocardiographic techniques, light and ultrastructural microscopy, fluorescence spectrometry and microscopy, scintigraphy, and in vitro image processing at the molecular level. (12 Dec 1998) |
| image field | <microscopy> Any field showing a focused image. There are a number of such fields in the complete microscopical system. The term may also denote the field of view, or the image field at the focal plane of the camera, generally the field where the final image is formed. (05 Aug 1998) |
| image intensifier | A device for converting a low light level fluoroscopic image to one that can be seen by the eye in a lighted environment; usually consists of an electronic light amplifier chained to a television tube. Synonym: image intensifier. (05 Mar 2000) |
| image interpretation, computer-assisted | Computer systems developed to aid in the interpretation of ultrasound, radiographic images, etc. (12 Dec 1998) |
| image processing, computer-assisted | A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer. (12 Dec 1998) |
| image real | <microscopy> An image as formed by a lens on a screen, plate or any plane surface. See: image, virtual. (05 Aug 1998) |
| image space | <microscopy> The space about an optical system each point of which is conjugate to some point in the object space. (05 Aug 1998) |
| image virtual | <microscopy> A virtual image has no real existence. It is the image seen when looking into a mirror. The field of view of the microscope is a good example of a virtual image. When the eye operates in conjunction with a lens to form an image on the retina, the visual sensation is as if the image existed in space. That its apparent location is very definite is proved when a pin can be made to coincide with the mirror (virtual) image of another pin that is seen by looking at a sheet of glass acting as a mirror. With a lens system a virtual image can be definitely located as by graphically tracing rays back to a focus. In a microscope, if the eye is relaxed as it should be, the virtual image will be at infinity. Measurements show that most observers place the aerial image at 20-25 feet, some as close as seven, because of partial accommodation. (11 Mar 1998) |
| imagery | <psychology> A cognitive-behavioural strategy that uses mental images produced by the imagination as a form of psychotherapy as an aid to relaxation. It can be classified by the modality of its content: visual, verbal, auditory, olfactory, tactile, gustatory, or kinesthetic. Common themes derive from nature imagery (e.g., forests and mountains), water imagery (e.g., brooks and oceans), travel imagery, etc. Imagery is used in the treatment of mental disorders and in helping patients cope with other diseases. Imagery often forms a part of hypnosis, of autogenic training, of relaxation techniques, and of behaviour therapy. (04 Jul 1999) |
| Abbe theory of image formation | <optics, physics> Abbe's theory is based on the fact that a non-self-luminous particle, which is illuminated by an extraneous source, gives rise to diffracted light rays, in addition to the dioptric pencil. He stated that to form a good microscopical image as many of the diffracted rays as possible should be intercepted by the objective. With closely ruled lines, his theory is easily demonstrated by observing the back lens of the objective, for here the diffracted rays can be observed directly if the aperture diaphragm is closed. It can be shown that, when the illumination is arranged to exclude the diffracted images, resolution is lost. (11 Mar 1998) |
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| accidental image | Continuation of visual impression after cessation of stimuli causing the original image. (12 Dec 1998) |
| body image | A term for the concept which each individual has of his own body as an object in and bound by space, independently and apart from all other objects. (12 Dec 1998) |
| radiographic image enhancement | Improvement in the quality of an X-ray image by use of an intensifying screen, tube, or filter and by optimum exposure techniques. Digital processing methods are often employed. (12 Dec 1998) |
| radiographic image interpretation, computer-assisted | Computer systems or networks designed to provide radiographic interpretive information. (12 Dec 1998) |
| real image | An image formed by the convergence of the actual rays of light from an object. Synonym: inverted image. (05 Mar 2000) |
| catatropic image | <ophthalmology, physiology> The two images formed by the anterior and posterior surfaces of the cornea and the two images formed by the anterior and posterior surfaces of the lens. Synonym: catatropic image, Purkinje images, Sanson's images. (05 Mar 2000) |
| virtual image | <microscopy> Such as seen in a mirror or through a magnifier. A virtual image has no real existence in space as does a real image from a lens. It does have a definite location, however, caused by the angles of divergence of the rays received by the eye. This can be shown by the common school experiment of placing a pin coincident with its mirror image behind a sheet of glass acting as a partial mirror. Its location can also be placed in design by extrapolating backwards to a focus. If a magnifier is used as it should be, with the object at its focus, the virtual image is at infinity. The same is true for a microscope focused for the relaxed eye. See: distance of virtual image. (05 Aug 1998) |
| visual image | A collection of foci corresponding to all the luminous points of an object. (05 Mar 2000) |
| retinal image | A real image formed on the retina. (05 Mar 2000) |
| mental image | A picture of an object not present, produced in the mind by memory or imagination. (05 Mar 2000) |
| phase image | A magnetic resonance image showing only phase shift information, to detect motion. (05 Mar 2000) |
| mirror image | A representation of an object or part thereof as its reflected image in a glass mirror. (05 Mar 2000) |
| mirror-image cell | A cell whose nuclei have identical features and are placed in the cytoplasm in similar fashion, a binucleate form of Reed-Sternberg cell often found in Hodgkin's disease; the twin nuclei are disposed in relation to an imaginary plane between them like a single nucleus together with its image in a mirror. (05 Mar 2000) |
| mirror image dextrocardia | Perfect right to left congenital reversal of the heart sometimes with other congenital abnormalities, sometimes normal except for position. (05 Mar 2000) |