Rad Phys exam 2 Spring 2015

Question 1

When the image on a film is very grey but the density is good, it is said to be?

Answer 1

low contrast

Question 2

Which technique would give the longest scale of CONTRAST?

Answer 2

110kV at 7.5 mAs

Question 3

The term “optimal kV” refers to?

Answer 3

the lowest possible mAs with acceptable contrast on the film

Question 4

What would the results be if you increased the kV to accomplish a doubling of the film density and cut the mAs in half?

Answer 4

the film density would remain the same and the contrast would decrease

Question 5

What is undesirable with magnification distortion?

Answer 5

the borders of the object will be blurred

Question 6

Which would double the number of photons?

Answer 6

going from a 100 mA station to a 200mA station

Question 7

How would an image appear if there was patient motion during exposure?

Answer 7

blurry

Question 8

What is true about x-ray beam?

Answer 8

exposure to it will cause x-ray film to darken, the greater its intensity the more penetrating it is, its intensity lessens as the distance increases from the source

Question 9

If you saw blood vessels on end (axillary) on a chest film, it would probably look like which four natural body densities?

Answer 9

metal

Question 10

Back scatter is most closely related to?

Answer 10

scatter that has been directed toward the tube

Question 11

Which of the following is true about increasing kV?

Answer 11

it will increase scatter from the patient

Question 12

the rays that exit the patient and hit the film are termed?

Answer 12

remnant rays

Question 13

Which would have the longest scale of CONTRAST?

Answer 13

5 mAs and 100 kVp

Question 14

If you wanted to increase contrast and maintain the same density of a previously taken film, what would you do?

Answer 14

double the mAs and decrease the kV by 15%

Question 15

Which is the recommended optimal kV range for lateral thoracic and lumbar?

Answer 15

85-95kV

Question 16

Recommended optimal kV range for cervical spine, AP thoracic and pelvis/hip?

Answer 16

75-85kV

Question 17

optimal kV range for AP lumbar?

Answer 17

80-90kV

Question 18

optimal kV range for AP full spine?

Answer 18

80-100kV

Question 19

mAs primarily influences which of the following? kV?

Answer 19

density…kV-contrast “kontrast”

Question 20

to decrease density of a previously taken film by 1/2, what would you do?

Answer 20

decrease mAs by 50%

Question 21

uses air gap technique?

Answer 21

lateral cervical

Question 22

which is preferred for spinal filming?

Answer 22

a fixed kV technique

Question 23

when using air gap technique, what is not needed?

Answer 23

grid

Question 24

preferred ratio for spinal filming?

Answer 24

10:1

Question 25

back scatter is most closely related to?

Answer 25

scatter that has been directed toward the tube

Question 26

what is the most common type of scatter radiation we will produce in our x-ray facility?

Answer 26

compton's

Question 27

what would the results be if you increased kV to accomplish a doubling of the film density and cut the mAs in half?

Answer 27

the film density would remain the same and contrast would decrease

Question 28

what is the term used when comparing the height of the absorbing strips to the width of the interspacing material of a grid?

Answer 28

grid ratio

Question 29

if you took a 14" x 17" film of a patients body part and then you wanted to take an 8" x 10" film of the same area with the central ray, kV and mAs the same and both collimated to size, what would you expect the outcome to be?

Answer 29

the 8 x 10 would be lighter than the 14 x 17

Question 30

if a film is too dark it is said to be?

Answer 30

overexposed

Question 31

when x-raying an elderly obese patient, what would be helpful in obtaining the best quality film?

Answer 31

using a lower kV in the optimal range

Question 32

if you compared two radiographs of a cervical spine with one having been taken at 40" and the other at 72" with the appropriate change in the radiographic technique, what would you find?

Answer 32

om the 72" film the image would be smaller and clearer

Question 33

if you saw two structures each with paralleling tracks of calcification overlying the articular pillars diverging at the superior closer at the inferior, what would you be looking at?

Answer 33

part of the thyroid cartilage

Question 34

what will absorb the most x-rays?

Answer 34

bone

Question 35

when looking at a cervical film you notice that one side is lighter than the other. what should you suspect is the cause of this appearance?

Answer 35

your focused grid has been installed backwards

Question 36

lateral cervical x-rays are too light but all the structure show up. used 50 kV at 10 mAs at 72" source image distance using a 400 speed screen. what is the best solution?

Answer 36

increase kVp by 15%

Question 37

what best describes the outcome of reducing the mAs by 1/2 and keeping the kV and distance constant?

Answer 37

the film density would decrease

Question 38

what would cause a decrease in subject density?

Answer 38

disuse atrophy

Question 39

what could be a problem if your X-ray tube was laterally shifted from the center of the film?

Answer 39

shape distortion

Question 40

recommended for the usual chiropractic office use?

Answer 40

a focused grid

Question 41

the height of a grid lead strips compared to the width between them is called what?

Answer 41

grid ratio

Question 42

if you wanted to alter your contrast so that a radiograph had more gray tones, what would you increase?

Answer 42

kV

Question 43

refers to an attenuation of part of the beam by the grid

Answer 43

grid cut off

Question 44

why is a fixed kV technique preferred?

Answer 44

contrast is consistent

Question 45

a film that is lighter on one side than the other most likely would indicate?

Answer 45

grid cut off

Question 46

best describes back scatter?

Answer 46

scatter that is directed toward the tube