| IAC | image analysis cytometry; ineffective airway clearance; internal auditory canal; interposed abdomina... |
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| IARS | image archival and retrieval system |
| IDA | idamycin; image display and analysis; iminodiacetic acid; insulin-degrading activity; iron deficienc... |
| IDB | image data baser |
| IGS | image-guided surgery; inappropriate gonadotropin secretion; internal guide sequence |
| 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) |
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| 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) |
| intermediate image plane | <microscopy> In a light microscope, the plane into which the objective lens directly focuses the image of the specimen. The plane is usually located a set distance (commonly 10 mm) below the shoulder for the ocular and another fixed distance (generally 160 mm) behind the rear focal plane of the objective lens. The ocular forms a virtual image of the intermediate image for visual observation, or projects a real image for photography and video microscopy. Note: The objective lens, combined with the coverslip of proper thickness, is corrected for projecting the primary image to the specified intermediate image plane only. (05 Aug 1998) |
| inverted image | An image formed by the convergence of the actual rays of light from an object. Synonym: inverted image. (05 Mar 2000) |
| optical image | An image formed by the refraction or reflection of light. (05 Mar 2000) |
| tactile image | An image of an object as perceived by the sense of touch. (05 Mar 2000) |
| eidetic image | Vivid mental image in the form of a dream, fantasy, or an unusual power of memory and visualization of objects previously seen or imagined. (05 Mar 2000) |
| false image | <ophthalmology> The image in the deviating eye in strabismus. (05 Mar 2000) |
| unequal retinal image | A condition in which the ocular image of an object as seen by one eye differs in size and shape from that seen by the other. (12 Dec 1998) |
| aperture for electron microscopy | <technique> Anode aperture: The opening in the accelerating voltage anode shield of the electron gun through which the electrons must pass to irradiate the specimen. Condenser aperture: An opening in the condenser lens controlling the number of electrons entering the lens and the angular aperture of the electron beam. The angular aperture can also be controlled by the condenser lens current. Physical objective aperture: A metallic diaphragm, with a small central hole, used to limit the cone of electrons accepted by the objective lens. This improves image-contrast since highly scattered electrons are prevented from arriving at the Gaussian image plane and therefore cannot contribute to background fog. Aplanatic. Free from spherical aberration and coma. (05 Aug 1998) |