collimation


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collimation

 [kol″ĭ-ma´shun]
1. in microscopy, the process of making light rays parallel; the adjustment or alignment of optical axes.
2. in radiology, the elimination of the more divergent portion of an x-ray beam.
3. in nuclear medicine, the use of a perforated absorber to restrict the field of view of a detector and reduce scatter.

col·li·ma·tion

(kol'i-mā'shŭn),
1. The method, in radiology, of restricting and confining the x-ray beam to a given area and, in nuclear medicine, of restricting the detection of emitted radiations from a given area of interest.
See also: laser, coherence.
2. A characteristic of laser light, in which all rays are nondivergent. The combination of collimation, coherence, and monochromatism produces, over a long distance, a bright, precise, finely focused beam.
See also: laser, coherence.
[L. collineo, to direct in a straight line]

collimation

The process in which the spread of a beam or field of radiation is reduced with a lead diaphragm, tube, or cone.

collimation

Radiation physics The formal process in which a beam or field of radiation is reduced with a lead diaphragm, tube, or cone

col·li·ma·tion

(kol'i-mā'shŭn)
1. radiology The process of restricting and confining the x-ray beam to a given area.
2. nuclear medicine Restricting the detection of emitted radiations from a given area of interest.
[L. collineo, to direct in a straight line]

collimation 

1. The making of a bundle of light rays parallel.
2. In radiography, limiting the size of the beam to the required region on the patient, thereby protecting the remainder of the patient from radiation.

col·li·ma·tion

(kol'i-mā'shŭn)
The method, in radiology, of restricting and confining the x-ray beam to a given area and, in nuclear medicine, of restricting the detection of emitted radiations from a given area of interest.
[L. collineo, to direct in a straight line]
References in periodicals archive ?
With the transparent display, we propose to simulate collimation by using Stereoscopy (figure 7).
(8) Thus, the use of the designation "rectangular collimation" has an implicit expectation of compliance with the standard established for it.
The first acts as collimation mirror while the second is a concentrating mirror (indicated as "Mirror" in S2 Figure 2 and L2 Figure 4).
Two of these six cases were acquired at 5.0 mm and one at 2.5 mm collimation. The other three cases were the two that involved perineural spread and the one that was without contrast such that the relationship with orbital contents was not well demonstrated.
The number of radiographers working in each hospital, years of experience and possible causes of inadequate beam collimation were derived from the questionnaires.
Other simple dose-reduction strategies include decreasing the tube current or tube voltage, increasing pitch, and choosing wider collimation. Decreasing tube current is often the most effective step toward dose reduction.
Radiation doses were reduced by 1.2 [micro]Gy per image for group A; the protocol included collimation. Besides DSA runs before and after embolization on each side, aortography was done as the final run.
We performed thoracic high-resolution computed axial tomography (HRCT), using 7 mm helical technique after intravenous contrast administration followed by high-resolution imaging, using 1 mm collimation every 1 cm from lung apex to base (Figure 1B-D).
Lens and prism coating refinements, focus calibration improvements, extremely precise collimation specifications, user-friendly eyecups and objective lens covers create the ultimate in binocular technology.
It can be attained by the magnetic collimation method, which is independent of the position of neutron [beta]-decay.
They include better collimation for cleaner signal and better cooling for extended life.
PolyLED lamps are solid-state light sources that provide the high reliability and light collimation associated with leaded discrete LEDs.