Rad Physics Sample Questions

Question 1

anatomy can affect film density through its variations of..

Answer 1

pathologies, tissue thickness, tissue age

Question 2

a satisfactory lateral lumbar spine radiograph is performed using 40 mAs at 84 kVp and a 14x17’ field size. If a spot view of L1 is performed using a 5x5 field size and the tequnique is not changed, how will this affect the radiograph?

Answer 2

decrease density

Question 3

the overal darkness of a radiograph is known as

Answer 3

density

Question 4

a technique of 400 mA and .05 sec and 75 kVp has been used to produce a radiograph. A second radiograph is taken, this time using 200 mA. How will this affect the radiographic density?

Answer 4

decrease enough to repeat the radiograph

Question 5

What effect does developer temperature have on the density of a radiograph?

Answer 5

developer that is too hot will increase the density of the film

Question 6

What can be expected if a radiograph normally taken at 72”, is inadvertently taken at 40”?

Answer 6

image underexposed

Question 7

Given an original technique of 30 mAs and 80kVp, which of the following will produce a radiograph with double the density?

Answer 7

60 mAs and 80kVp

Question 8

In the diagnostic xray range, the smallest change in mAs that can be perceived on a radiograph is?

Answer 8

30%

Question 9

A device that is commonly used to even out radiographic density, due to different patient part thickness is a

Answer 9

compensating filter

Question 10

compared with 200 speed cassettes, 400 speed screen cassettes

Answer 10

require less xrays to get the phosphors to emit enough light to transfer the information

Question 11

A lateral cervical was taken at 40” using 7.5mAs at 75 kVp the density was optimal. The tech remembered lateral cervical films are to be taken at 72”, what will the new technique be?

Answer 11

22.5mAs at 75 kVp

Question 12

An increase in SID/FFD with no change in technique will result in a radiograph with

Answer 12

decreased density; decreased detail

Question 13

the routine care of radiographic intensifying screens requires that they be:

Answer 13

periodically cleared with a specific screen cleanser

Question 14

an increase in OID/OFD will ___film density.

Answer 14

decrease

Question 15

compared with 400 speed screen cassettes, 200 speed screen cassettes

Answer 15

require more xrays to get the phosphors to emit enough light to transfer the information

Question 16

short exposure times are recommended for improving

Answer 16

motion

Question 17

which of the following would be used to reduce magnification?

Answer 17

shortest possible OID

smallest focal spot size

Question 18

select the technique taht would produce a film with the highest contrast on an AP lumbopelvic projection?
300mA, .1sec, 80kVp
300 mA, .1 sec, 110 kVp
300mA, .1 sec, 75kVp
300 mA, .1 sec, 60 kVp

Answer 18

300 mA, .1 sec, 60 kVp

Question 19

15mAs at 65 kVp
the above technique produces an optimal quality radiograph on a 200 speed screen cassette. if a 400 speed screen cassette is used and the technique is not changed. How will this afect the radiographic density?

Answer 19

there will be a significant increase in density, enough to alter the technique

Question 20

what do you do to reduce radiographic unsharpness?

Answer 20

decrease screen speed
decrease focal spot size
decrease OID

Question 21

as mAs is decreased from 50 to 25

Answer 21

radiographic density decreases

Question 22

select the answer that arranges patient densities in order from most radiolucent to most radiopaque

Answer 22

gas, muscle, bone, metal

Question 23

select the technique that would produce a radiograph with the most density
300mA, .1 sec and 90 kVp
300mA, .1 sec, 60kVp
300mA, .1 sec, 110kVp
300 mA, .1 sec, 75 kVp

Answer 23

300 mA, .1 sec, 110kVp

Question 24

the 15% rule states that

Answer 24

density may be halved by decreasing kVp by 15%

Question 25

magnification is caused by

Answer 25

an incrased OFD

Question 26

which of the following may be used to control motion duringa radiographic exam?

Answer 26

immobilization devices (non threatening)
precise instructions
shortest possible exposure time

Question 27

a technique of 400mA and .05 sec and 75 kVp has been used to produce a radiograph. A second radiograph is taken, this time as 200mA. How will this affect the radiographic detail?

Answer 27

decrease enough to repeat the radiograph

Question 28

an increased SID/FFD with no change in technique will result in a radiograph with?

Answer 28

decreased density, decreased detail

Question 29

an increase in OID/OFD will___film detail

Answer 29

decrease

Question 30

short exposure times are recommended for improving?

Answer 30

motion

Question 31

which of the following would be used to reduce magnification?

Answer 31

shortest possible OID

longest FFD/SID

Question 32

select the technique that would rpoduce a film with the highest contract on AP lumbopelvic projection
300mA, .1sec, 80kVp
300mA, .1sec, 110 kVp
300mA, .1 sec, 75kVp
300mA, .1 sec, 60 kVp

Answer 32

300mA, .1 sec, 60 kVp

Question 33

which of the following can be used to reduce radiographic unsharpness?

Answer 33

decrease screen speed
decrease focal spot size
decrease OID

Question 34

the 15% rule states that

Answer 34

density may be halved by decreased kVp by 15%

Question 35

magnification is caused by

Answer 35

an increased OFD

Question 36

which of the following may be used to control motion during a radiographic examination?

Answer 36

immobilization devices (non threatening)
precise instructions
shortest possible exposure time

Question 37

list 3 that can clean up scatter

Answer 37

recumben radiographs, grid compression bands, low kVp

Question 38

an APLP radiograph was taken table top using 25mAs @ 75kVp. The tech remembered after taking the film that APLPs are taken using the bucky. How will the radiographic detail be affectd if same technique is used?

Answer 38

will decrease detail

Question 39

a grid must be used when the part measures more than___cm

Answer 39

10-11cm