RADD 2501 Animal Insides Lecture - Radiographic Equipment

RADD 2501 Animal Insides Lecture - Radiographic Equipment -...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 4 Lecture 4: Other radiographic equipment In this Lecture ¾ Learn about x-ray beam limiting devices ¾ Learn about grids. What they are. Why they are great. The drawbacks of using grids. Finally, understand the appropriate use of a grid. ¾ Know what a cassette is ¾ Know what intensifying screens are. Why we use them. The drawbacks of using them. ¾ Know about film color sensitivity and why it is important. O.k. so far we made some x-rays, the x-rays went out of the x-ray tube, hit the patient, interacted with the patient, and we started to talk about a radiographic image. We got stuck for a little while on the subject of scatter and the fact that it causes a crummy image. In this lecture we will continue to look at ways that we can make a better image. In order to do so, we will look at additional equipment necessary to make the image. In later lectures, we will look at things that we can do with this equipment in order to make a pretty picture. We start with that nagging question…what is collimation? X-ray beam limiting devices P reviously we said that it was important to limit the size of the x ray field. There are two reasons for this: 1. Smaller fields mean less scatter. Less scatter means a better image. If this sounds redundant, it is. It is important. 2. Smaller fields mean less exposure for the patient. Remember, we want to reduce the amount of ionizing radiation that our patients receive. There are many devices used to accomplish this task of decreasing the size of the x-ray field. Cones, cylinders, and aperture diaphragms have been used in the past. Currently, the standard technology is the collimator .
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Collimators allow a variety of x-ray field sizes to be selected by using a series of lead shutters and a light beam that shows the size of the field. Most systems use a mirror to align the light field. Some portable systems use a laser to center the field.
Background image of page 2
Collimators do not focus the x-ray beam, they merely shape it by cutting off the edges of the beam. Again, collimators simply exclude the part of the beam we don’t want to use. Since x-rays do not have a mass or charge, they cannot be focused. Collimators are not fool proof. The mirror system can get out of whack. Therefore, a good maintenance schedule will evaluate the accuracy of the collimator light on a routine basis. A good description of how this test is performed can be found on page 28 of Morgans’s Techniques of Veterinary Radiography listed in the reference list. Grids: ummm more on scatter W e said numerous times that good collimation will reduce scatter. However, even though we try to limit the exposed field, tissue is, of course, exposed and scatter is produced. Anytime scatter hits the film, there is image degradation. A grid is used to reduce scatter from hitting the film a grid is used. Keep in mind that grids do not decrease scatter formation, they just stop scatter from hitting the film. Grids should be used anytime a body part thicker than 10cm is radiographed.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/22/2011 for the course RADD 2501 taught by Professor Sandyeverage during the Winter '11 term at Life Chiropractic College West.

Page1 / 14

RADD 2501 Animal Insides Lecture - Radiographic Equipment -...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online