Radiographic Density

Question 1

Define Radiographic Density

Answer 1

Visibility of detail factor that describes the amount of blackness seen on an image (background blackness brightness indication)

Question 2

What radiographic density is directly related to?

Answer 2

To quantity (amount) of radiation reaching IR

Question 3

When sufficient radiographic density is achieved

Answer 3

When the bony and soft tissue structures of interest are visualized

Question 4

What mAs is controlling factor of?

Answer 4

quantity or amount of radiation

Question 5

What an increase and decrease in mAs will do to Radiographic Density (with adequate penetration)

Answer 5

increase= increase in Radiographic density
decrease= decrease in radiographic density

Question 6

What excessive mAs demonstrates on image

Answer 6

Density that is so dark that some or all of bony and soft tissue structures of interest are not well visualized it will be too dark

Question 7

How to determine between if too much mAs or kVp was used on a dark image

Answer 7

evaluating the image contrast

Question 8

What an overexposed image using too much mAs demonstrates

Answer 8

acceptable contrast as long as kVp used is optimal

Question 9

How an overexposed image using too much mAs will appear

Answer 9

overall dark, the cortical outlines of the bone should remain high in contrast

Question 10

What an underexposed image using insufficient mAs demonstrates

Answer 10

Density that is so light that some or all of the anatomic structures cannot be seen or evaluated

Question 11

How an underpenetrated (kVp) image will appear

Answer 11

image will not demonstrate the cortical outlines that were not penetrated

Question 12

Controlling factor of image density

Answer 12

mAs

Question 13

what 30% change in mAs will demonstrate?

Answer 13

adjusts the image density just enough for the eues to be able to visualize that a change was made

Question 14

When is it ideal to use the 30% rule

Answer 14

when an image demonstrates acceptable but not optimal density and needs to be repeated because of a factor other than density (artifact, motion)

Question 15

what will a change in mAs be on an image that is borderline too light

Answer 15

100% increase in mAs

Question 16

what will a change in mAs be on an image that is borderline too dark

Answer 16

50% decrease in mAs

Question 17

what will a change in mAs be on an image so light or dark it will have to be repeated

Answer 17

3-4 times the increase or decrease in mAs

Question 18

How kVp affects radiographic density

Answer 18

is affected by a change in kVp because it alters the quality of photons

Question 19

How mAs compensates for insufficient kVp if possible

Answer 19

NO AMOUNT

Question 20

Define optimum kVp

Answer 20

kVp that will provide adequate part penetration and sufficient gray scale

Question 21

How image that has been adequately penetrated will appear

Answer 21

demonstrates the cortical outlines of the thinnest and thickest bony structures of interest

Question 22

what factor is automatically set with AEC

Answer 22

mAs

Question 23

what factor technologist must set with AEC

Answer 23

optimum kVp level

Question 24

Define minimum response time

Answer 24

the time it takes for the circuit to detect and react to radiation received

Question 25

with reference to AEC what results in underexposed images

Answer 25

failure to properly activate correct ionization chambers and to not center the anatomic structure over them

Question 26

when using the AEC why its important to use tight collimation

Answer 26

to reduce scatter radiation that may cause the AEC to shut off prematurely

Question 27

what situations or conditions will prohibit you from using AEC

Answer 27

when any type of radiopaque hardware or prosthetic device will be positioned over activated chamber

Question 28

What changes the 1 button and 2 button imply when using them for density control

Answer 28

1- 25% density change

2- 50% density change

Question 29

What increasing SID does to radiographic density

Answer 29

decreases

Question 30

what decreasing the SID does to radiographic density

Answer 30

increases

Question 31

what is the % of change in SID for a visible density change

Answer 31

20%

Question 32

how increasing OID affects density

Answer 32

could result in a noticeable density loss

Question 33

what must be done to mAs when changing to a higher grid ratio and how this will affect density

Answer 33

increase mAs, or insufficient density

Question 34

what must be done to mAs when changing to a lower grid ratio and how it affects mAs

Answer 34

decrease in mAs

Question 35

How to distinguish grid cut off from other density problems

Answer 35

appearance of grid lines on the image

Question 36

what the amount of density change depends on

Answer 36

field size and the amount of scatter that would typically reach IR

Question 37

why compensating filter is used

Answer 37

to offset the thickness difference and obtain optimum density throughout entire images

Question 38

how you should set your technique when using a compensating filter

Answer 38

set a technique that will adequately penetrate the thickest portion of the anatomic structure of interest

Question 39

when you should use Anode Heel Effect

Answer 39

when positioning long bones and the vertebral column when a long 17” field length is used

Question 40

which end produces more photons

Answer 40

cathode

Question 41

when using anode heel effect what part of structure will be placed under anode end of the tube and cathode end of the tube

Answer 41

anode-thinner side of structure

cathode-thicker side of the structure

Question 42

what part of tube represents + or - symbols

Answer 42

\+= anode
- = cathode

Question 43

how mAs should be set with anode heel effect

Answer 43

to adequately demonstrate the midpoint of structure (where CR will enter)

Question 44

what using anode heel effect demonstrates on the finished image

Answer 44

a more uniform density across the part