Radiographic Contrast Studies

Question 1

What are contrast media used for?

Answer 1

To visualise soft tissue structures that are difficult to identify clearly on plain films due to lack of surrounding contrast.

Question 2

What information can be gained using contrast media?

Answer 2

Position, size, shape, internal surface, and function of the tissue.

Question 3

What are the two major types of contrast media?

Answer 3

• Negative contrast media
• Positive contrast media

Question 4

What are negative contrast media?

Answer 4

Gases with low atomic numbers and low density that appear black on the radiograph (radiolucent).

Question 5

List examples of negative contrast media.

Answer 5

• Air
• Oxygen
• Nitrous oxide
• Carbon dioxide

Question 6

What are the advantages of negative contrast media?

Answer 6

• Cheap
• Quick
• Convenient (especially air)
• Safe
• Reabsorbed fairly quickly

Question 7

What are the disadvantages of negative contrast media?

Answer 7

• Poor mucosal detail when used alone
• Risk of air embolism if tissue is inflamed

Question 8

What are positive contrast media?

Answer 8

Substances that are radiodense / radiopaque due to their high atomic number and high density.

Question 9

What is barium sulphate and its forms?

Answer 9

An inert substance available as a powder, paste, or liquid that is not absorbed by tissues.

Question 10

What is the main use of barium sulphate preparations?

Answer 10

Studies of the alimentary tract.

Question 11

What are the risks associated with using barium in the nasal chamber?

Answer 11

Risk of inhaling barium and setting up aspiration pneumonia as it is not readily absorbed.

Question 12

What are some products that contain barium sulphate?

Answer 12

• Micropaque
• Microtrast
• BIPS

Question 13

What are lonic water soluble iodine containing compounds derived from?

Answer 13

Iodine and benzoic acid

These compounds are used in various medical imaging procedures.

Question 14

How are lonic water soluble iodine containing compounds excreted?

Answer 14

By the kidneys after intravenous injection

This is important for understanding their pharmacokinetics.

Question 15

For what studies are lonic media mainly used?

Answer 15

Intravenous studies

They can also be used for gut studies if perforation is suspected.

Question 16

What happens when lonic media are used for gut studies?

Answer 16

They are progressively diluted

This is due to their hypertonic nature, which draws water into the intestines.

Question 17

List two side effects from intravenous use of lonic media.

Answer 17

• A fall in blood pressure
• Whining or retching on administration

Other side effects may include irritation if given perivascularly.

Question 18

What severe reaction may occur very rarely with lonic media?

Answer 18

An anaphylactic reaction

This highlights the importance of monitoring patients after administration.

Question 19

Why must lonic media not be used for myelography?

Answer 19

High osmotic pressure causes severe damage to nervous tissue

This can potentially be fatal.

Question 20

What is a key characteristic of non-ionic water soluble iodine containing compounds?

Answer 20

They do not carry an ionic charge

This results in lower osmotic pressure compared to ionic media.

Question 21

What is the recommended storage condition for non-ionic iodine compounds?

Answer 21

Kept out of light at temperatures less than 30°C

Proper storage is crucial for maintaining their efficacy.

Question 22

What are cholecystopaques used for?

Answer 22

Detecting gall bladder rupture

They are actively secreted by the liver as bile into the gall bladder.

Question 23

What was the purpose of viscous or oily agents like Dionosil?

Answer 23

Used for bronchial examinations

These agents are no longer available.

Question 24

What are double contrast studies?

Answer 24

Double contrast studies use negative contrast media in combination with positive contrast media to enhance visualization of structures like the bladder, gut, and joints.

The positive contrast media coats the mucosal surface, providing good visualization of the mucosa.

Question 25

What is arthrography?

Answer 25

Arthrography is a radiographic examination that shows the internal structure of a joint, involving the injection of air and/or a positive contrast medium into the synovial fluid. ## Footnote Radiographs should be taken within 1 minute of injection to prevent absorption of contrast media.

Question 26

What are the two types of arthrography?

Answer 26

The two types of arthrography are: * Indirect - Contrast material is injected into the bloodstream, absorbed into the joint. * Direct - Contrast material is injected directly into the joint, providing better detail and distension for visualization. ## Footnote Direct arthrography allows for clearer imaging of joint structures.

Question 27

What is bursography?

Answer 27

Bursography is the radiographic visualization of a bursa after injection with a contrast medium, such as in the examination of the navicular bursa in the equine hoof. ## Footnote This technique helps in assessing conditions related to bursae.

Question 28

What does fistulography involve?

Answer 28

Fistulography involves the radiographic examination of a fistula after introducing contrast media through its external opening under aseptic conditions. ## Footnote This method helps visualize the anatomy and condition of the fistula.