Pathology-Contrast Media

Question 1

What are contrast agents used for?

Answer 1

To create contrast against a background of similar tissues

Question 2

What do contrast media have a high rate of?

Answer 2

High x-ray absorption

Question 3

How much more absorption do contrast agents produce when compared to soft tissue?

Answer 3

Absorption can be hundres of times higher

Question 4

What are the two types of contrast agents?

Answer 4

Postitive and Negative

Question 5

What is positive contrast?

Answer 5

Agent that is more absorbant to x-ray than surrounding tissues

Question 6

How does positive contrast show up on an x-ray?

Answer 6

White

Question 7

What are two types of positive contrast?

Answer 7

Barium and iodine

Question 8

What makes barium and iodine good contrast agents?

Answer 8

Both have a high atomic number, with lots of orbital electrons that can which can be interacted with and increase absorption

Question 9

What is negative contrast?

Answer 9

Agents that are less absorbant to x-ray than surrounding tissues

Question 10

How does negative contrast show up on an x-ray?

Answer 10

Black

Question 11

What are examples of negative contrast?

Answer 11

Gases like air and carbon dioxide

Question 12

How does contrast impact kVp used?

Answer 12

Higher kVp needs to be used when using contrast to ensure adequate penetration

Question 13

What kVp should be used for iodine contrast?

Answer 13

kVp between 80-100

Question 14

What kVp should be used for solid column barium contrast?

Answer 14

kVp of 120

Question 15

How do contrast agents affect binding energy?

Answer 15

Contrast brings up the binding energy of the tissue closer to the x-ray energy, which causes more photoelectric effect and appears brighter

Question 16

What types of interactions occur as a result of contrast agents?

Answer 16

Photoelectric interactions

Question 17

What is pathology?

Answer 17

Abnormal changes due to disease, trauma or medical intervention that can affect technical factors used in radiographic procedures

Question 18

Who’s responsibility is it to interpret patient requisitions?

Answer 18

The radiographer, as the standard techniques might not qualify

Question 19

What are the two ways in which diseases are broken down?

Answer 19

Additive or Destructive

Question 20

What are additive conditions?

Answer 20

Conditions that increase bone, fluid or metal

Question 21

What do additive conditions require when it comes to exposure?

Answer 21

An increase in exposure

Question 22

What are some examples of additive diseases that require increased technique?

Answer 22

Pneumoconiosis, Pneumonia, Cardiomegaly, Cirrhosis, Edema, Hydrocephalus, Tuberculosis

Question 23

What are destructive conditions?

Answer 23

Conditions that lead to a decrease in air or fat, fluid or bone

Question 24

What do destructive conditions require when it comes to exposure?

Answer 24

A decrease in exposure

Question 25

What are some examples of destructive diseases that require decreased technique?

Answer 25

Aseptic necrosis, gout, emphsyema, bowel obstruction, osteoporosis, rheumatoid arthritis

Question 26

What is the mimumum change to exposure that can be made to produce a significant difference?

Answer 26

Change up/down in mAs by 35% or change up/down in kVp by 5%

Question 27

If part thickness increases by 4 cm above the average how should exposure be updated?

Answer 27

It should be doubled, which is either a 15% increase in kVp or 2X the mAs

Question 28

How should radiographic technique be adjusted for large muscular patients?

Answer 28

It should be increased by an additional 35-50%

Question 29

How should radiographic technique be adjusted for older patients?

Answer 29

It should be decreased because of the mineralization of bones

Question 30

How should radiographic techniques be adjusted for trauma?

Answer 30

Can necessitate and increase anywhere from 35-100%

Question 31

How should radiographic techniques be adjusted for postmortem examinations?

Answer 31

Require an increase from 35-50%

Question 32

How should radiographic techniques be adjusted for foreign bodies?

Answer 32

Requires a decrease in exposure by 20%

Question 33

What other post production factor can assist in diagnosing foreign bodies/

Answer 33

Digital windowing

Question 34

What factors in casts and splints affect changes in exposure?

Answer 34

If you plaster or not, how thick the cast is and whether it is wet or dry