Ultrasound Contrast Agents

Question 1

Contrast agent used in fluoro/xray?

Answer 1

Barium

Question 2

Contrast agent used in CT?

Answer 2

Iodinated contrast

Question 3

Contrast agent used in MRI?

Answer 3

Gadolinium

Question 4

Contrast agent used in ultrasound?

Answer 4

Microbubbles

Question 5

Size of microbubbles?

Answer 5

1-4 microns

Question 6

What do the microbubbles consist of?

Answer 6

PEG shell and gas core

Question 7

What structures are taken up by the microbubbles?

Answer 7

Spleen, liver, immune system

Question 8

What kind of echoes are produced when microbubbles expand and contract?

Answer 8

Harmonic echoes

Question 9

What does encapsulation of the gas refer to?

Answer 9

Slows the diffusion of the gas and lengthens duration of contrast effect

Question 10

What lengthens the duration of the contrast effect?

Answer 10

Encapsulation

Question 11

What does CEUS stand for?

Answer 11

Contrast Enhanced US

Question 12

What is flash mode?

Answer 12

A short ultrasound pulse with a high MI that destroys the microbubbles

Question 13

What contrast agent brand is used here?

Answer 13

Definity

Question 14

Benefits of contrast agents?

Answer 14

1. Real-time evaluation of blood flow
2. Destruction of microbubbles to quantify tissue perfusion
3. Safer - no radiation
4. Cheaper
5. Low dosage needed because microbubbles are very strong

Question 15

Disadvantages to contrast agents?

Answer 15

1. Microbubbles only last a short time in the body
2. Microbubbles will burst at low frequencies and high MI
3. Reactions to the contrast are possible

Question 16

Side Effects of Definity?

Answer 16

1. Headache/Dizziness
2. Flushed
3. Nausea
4. Chest pain
5. Low back or side pain

Question 17

What can microbubbles be targeted with?

Answer 17

Ligands

Question 18

Benefit of target contrast agents?

Answer 18

Taken up by the body at a specific area of interest such as inflamed cells or cancer cells

Question 19

T or F? Contrast target agents are still under pre-clinical development?

Answer 19

TRUE

Question 20

As bubbles pass through the US window, they act as what kind of reflector?

Answer 20

Strong reflectors relative to blood and tissue

Question 21

What may contrast agents be used for?

Answer 21

1. LV opacification and endocardial border detection
2. Lesion detection when echogenicity matches the surrounding tissue
3. Lesion characterization - blood flow
4. Doppler detection when echoes are weaker
5. Small bowel in cases of chron’s disease