| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,726,323,176 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
collimation |
Also found in: Dictionary/thesaurus, Encyclopedia, Wikipedia | 0.01 sec. |
|
collimation /col·li·ma·tion/ (kol″ĭ-ma´shun) 1. in microscopy, the process of making light rays parallel; the adjustment or aligning 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.
collimation (kol´imā´sh n in radiology, collimation refers to the elimination of the peripheral (more divergent) portion of a useful radiographic beam by means of metal tubes, cones, or diaphragms interposed in the path of the beam. See also diaphragm. collimation, rectangular,
n a method for minimizing a patient's exposure to unnecessary radiation during treatment by using a rectangular position-indicating device (PID) to reduce the size of the radiation beam. collimation in microscopy, the process of making light rays parallel; the adjustment of two or more optical axes with respect to each other. In radiology, the restriction of the beam size to the area under investigation. This reduces the scattered radiation reaching the x-ray film and the exposure of attendants.
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. collimation Radiation physics The formal process in which a beam or field of radiation is reduced with a lead diaphragm, tube, or cone How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| ? Mentioned in | ? References in periodicals archive | ||
|---|---|---|---|
| Other problems have included improper collimation, no purging and incorrect zero diopter settings and infinity focus. 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). Similarly, a second set of collimation apertures constrains the transverse electron momentum. |
| Medical Dictionary |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|