Beam restriction

Question 1

scatter is produced at what level?

Answer 1

Patient level

Question 2

what is beam restriction?

Answer 2

collimation or field size

Question 3

when collimating, like on a L5 spot what do we change to compensate for the loss of scatter?

Answer 3

increase mAs

Question 4

what is tissue interaction (scatter) called?

Answer 4

Compton interaction

Question 5

how does Compton interaction occur?

Answer 5

photon, interacts with a outer-shell electron

Question 6

what is produced in a Compton interaction?

Answer 6

scatter photon NEEDS MORE INFO

Question 7

kVp in relation to scatter.

Answer 7

High kVp 
long scale contrast 
low rad. contrast 
short wavelength 
Compton Interaction predominates (70-100 kVp)
image quality goes down

Question 8

why is there higher scatter other than high kVp

Answer 8

Compton scatter

Question 9

bone effective Z# is?

Answer 9

13.8

Question 10

soft tissue effective z# is?

Answer 10

7.4

Question 11

bone will have____ scatter than soft tissue

Answer 11

less

Question 12

what is the relationship between z# and scatter production?

Answer 12

less scatter b/c higher Z# = more absorption

Question 13

fat z# is ?

Answer 13

6.3

Question 14

contrast media will hav what effect on scatter?

Answer 14

less scatter b/c Higher Z#= more absorption

Question 15

iodine Z# is?

Answer 15

56

Question 16

Barium Z# is?

Answer 16

53

Question 17

Air Z#?

Answer 17

7.6

Question 18

A high Z# material will create a high contrast image.

T/F

Answer 18

True

Question 19

the tech. changes from 110 kVp to 60 kVp, the image will illicit a short scale of contrast.
T/F

Answer 19

True