FREE RADIOLOGY AND STUDY GAMES ABOUT BEAM

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FREE RADIOLOGY AND STUDY GAMES ABOUT BEAM

RESTRICTING EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -37 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: Where is the filter located?

Answer:

between the sourece and patient at collimator housing Question 2: What are the requirements for the mm AL used if the kVp range was 70-100?

Answer:

2.5 required; 3.0 recommened Question 3: Also known as the variable aperture collimator; it is most common in diagnostic radiography

Answer:

PBL - positive beam limitation (automatic collimation)

Question 4: What is the purpose of the compensating filters?

Answer:

Even out density of body parts with unequal thickness

Question 5: Filters have an affect on scatter. T/F

Answer:

False - they have nothing to do with scatter Question 6: What type of test can be performed to see your collimators accuracy?

Answer:

8-9 penny test; checks for collimator cutoff

Question 7: Ability to distinguish between two similar tissues

Answer:

Contrast Resolution

Question 8: Image detail or visibility of detail

Answer:

the sharpness of small structures Question 9: What are the requirements for the mm AL used if the kVp range was greater than 100?

Answer:

3.0 required Question 10: What are the requirements for the mm AL used if the kVp range was 50-70?

Answer:

1.5 required

Question 11: What is total AL filtration?

Answer:

inherent plus added AL layer Question 12: Measurement of the amount of absorber required to reduce intial beam intesnity by 1/2 or 50%.

Answer:

Half value layer

Question 13: Where is the lead aperture diaphragm located?

Answer:

Between the anode and the patient

Question 14: Main purpose of Filters.

Answer:

Harden the beam to reduce patient skin exposure

Question 15: What is the purpose of the mirror in the PBL?

Answer:

project light image onto patient; sits at a 45 degree angle and sits exactly between the light source and focal spot siz

Question 16: Ghosting is due to what?

Answer:

off focus radiation (stem radiation) - electrons radiation does not hit target correctly

Question 17: Entrance shutters

Answer:

immovable circular piece of lead mounted below focal spot; purpose is to absorb any off focus or stem radiation Question 18: What affect do filters have on image quality (contrast and density)?

Answer:

density - decreases density as eliminates quantity of beam usedcontrast - lower contrast as leaves with higher kVp Question 19: If collimation is increase, what will happen to pt. dose, density and contrast?

Answer:

decrease pt. dose, decreased density, increased contrast with proper compensation for density loss Question 20: If field size is increased (open up collimator), what will happen to pt. dose, scatter, density and contrast?

Answer:

increased patient dose, increased scatter, increased density and decreased scatter

Question 21: Explain why kVp can have such an influence on the intensity of scatter reaching the IR?

Answer:

Increased kVp will allow for more penetration of beam and there will be lower patient dose (due to less attenuation) but an increase in scatter and decrease in image contrast

Question 22: What type of material do we use in filters?

Answer:

aluminum or can be a combination of aluminum and copper Question 23: What are the requirements for the mm AL used if the kVp range was less than 50?

Answer:

.5 required

Question 24: How do filters reduce patient dose?

Answer:

absorbs low energy, long wavelength radiation that contributes to skin dose and leaves higher nergy, short wavelength beam which has more penetration.

Question 25: Moveable lead shutters

Answer:

controlled by tech; helps to reduce the beam

Question 26: What are three types of beam restricting devices?

Answer:

aperture diaphragm, cones and cylinders, variable aperture diaphragm (PBL) Question 27: What is the simplest type of beam restricting device that is attached to the head of x ray tube?

Answer:

aperture diaphragm

Question 28: Ability to image small objects that have high subject contrast.

Answer:

Spatial Resolution