scientific principles

Question 1

what does kV stand for

Answer 1

Energy of X-Rays emerging from X-Ray tube(kV)

Question 2

What does kVp stand for ?

Answer 2

Maximum energy of X-Rays from X-Ray tube

Question 3

Higher kV =

Answer 3

higher penetration

Question 4

how do we measure kV?

Answer 4

joules per Coulomb

Question 5

what does kv stand for ?

Answer 5

kilo volatge

Question 6

What does mA stand for ?

Answer 6

Milli amps

Question 7

define current

Answer 7

Number of X-Rays emerging from X-Ray tube

Question 8

what is current measured in ?

Answer 8

mA

Question 10

Higher mA higher number of photons=

Answer 10

Higher intensity

Question 11

what does mAs stand for ?

Answer 11

Milli Amp Seconds

Question 12

def mAs

Answer 12

Product of mA and length of time X-Rays are produced

Question 13

how can we change mAs ?

Answer 13

Vary mA or time to get different mAs

Question 14

Not enough mAs =

Answer 14

Not enough photons

Question 15

Lack of photon density and contrast as a result of low mAs can result in ?

Answer 15

Low “photon density”

Question 16

what can not enough kV result in ?

Answer 16

-not enough energy to penetrate:
-Tissue Density
-Tissue Thickness

Question 17

what is another result of low kV ?

Answer 17

Very “black and white” images

Question 18

what can high mAs result in ?

Answer 18

Too many photons
high “photon density”

Question 19

if to many photons hit the image receptor what can occur

Answer 19

loss of visible anatomy
Reduced contrast

Question 20

def di

Answer 20

di value is a feedback system which tells you whether or not the exposure you are giving is optimal

Question 21

what can too high kv result in

Answer 21

High energy and so can penetrate too much

Question 22

High energy and so can penetrate too much (high kV) why is this bad ?

Answer 22

Loss of visible anatomy
Low contrast
Image appears “grey”

Question 23

list the properties of an x-ray tube ?

Answer 23

Deceleration of fast moving electrons
Radiation protection and primary beam
Electrical protection
Dissipation of heat

Question 24

elections go from ca… to a…. in x-ray tube ?

Answer 24

cathode and anode.

Question 25

where is the cathode ?

Answer 25

in the filament

Question 26

list the properties of the fillament ?

Answer 26

-tungsten
– Good thermionic emitter
-Low vapour pressure
-Highly ductile
-Current (mA)

Question 28

what is the plane orientation of the knee ?

Answer 28

*The knee joint line is in an axial orientation
*(it is perpendicular to the sagittal and coronal planes)

Question 29

what must you think about in term of planes when x-raying a patient ?

Answer 29

• Think about the joint space and its orientation
• Consider how the limb must be positioned so that the primary beam can pass through the joint(s)

Question 30

def Superimpose

Answer 30

2 anatomical features are placed in the same plane

Question 31

define Equidistant

Answer 31

at equal distances