radiology

Question 1

How does x-ray create an image

Answer 1

• a radiation beam of electrons is pushed through the body

- the beam will knock off and replace electrons from atoms in the body creating a release of x-ray energy

Question 2

what is the primary beam of an x-ray

Answer 2

Release of the radiating energy is like a light bulb and the radiating beam is therefore release from a housing that control the direction of the radiation so that only the target tissue is radiated

Question 3

What is collimation

Answer 3

the process by which the primary beam is manipulated to maximize optimal beam angle and image resolution. 90 degree orientation is the goal. the smaller the beam the greater then image resolution.

Question 4

what are some different filters placed on an x-ray that help improve image quality

Answer 4

• aluminum filters will absorb low frequency radiation allowing for better image quality
• bucky filters will absorb x-ray photons that are not moving parallel to the film plate (draw back is that it requires more radiation, but hopefully less retakes)

Question 5

What is x-ray heel effect

Answer 5

• imaging artifact
• the anode heel effect is a variation of the intensity of X-rays emitted by the anode depending on the direction of emission. Due to the geometry of the anode, X-rays emitted towards the cathode are in general more intense than those emitted perpendicular to the cathode–anode axis. The effect stems from the absorption of X-ray photons before they leave the anode in which they are produced. The probability of absorption depends on the distance the photons travel within the anode material, which in turn depends on the direction of emission

Question 6

How doe the x-ray tech compensate for the heel effect

Answer 6

place the thicker part of the body under the anode

Question 7

What can under penetration produce with x-ray

Answer 7

you can pick up some soft tissue contrast

Question 8

what are the principle sources of x-ray error

Answer 8

1. enlargement
2. elongation
3. foreshortening
4. superimposition

Question 9

How does the enlargement imaging error occur

Answer 9

• the further a tissue is from the source of the beam the more it is enlarged
• objects closer will be smaller than those behind it

Question 10

What is the elongation error with x-ray imaging

Answer 10

parallax effect

- similar to the enlargement effect because it results from the path of the radiation beams.

Question 11

what is foreshortening error

Answer 11

what the target tissue is not parallel to the beam it is subject to distortion via the enlargement effect of the varying distances from the beam source

Question 12

what is the superimposition affection

Answer 12

the stacking of tissue creating artificial looking lines