Ultrasound Contrast Agents Flashcards
Contrast agent used in fluoro/xray?
Barium
Contrast agent used in CT?
Iodinated contrast
Contrast agent used in MRI?
Gadolinium
Contrast agent used in ultrasound?
Microbubbles
Size of microbubbles?
1-4 microns
What do the microbubbles consist of?
PEG shell and gas core
What structures are taken up by the microbubbles?
Spleen, liver, immune system
What kind of echoes are produced when microbubbles expand and contract?
Harmonic echoes
What does encapsulation of the gas refer to?
Slows the diffusion of the gas and lengthens duration of contrast effect
What lengthens the duration of the contrast effect?
Encapsulation
What does CEUS stand for?
Contrast Enhanced US
What is flash mode?
A short ultrasound pulse with a high MI that destroys the microbubbles
What contrast agent brand is used here?
Definity
Benefits of contrast agents?
- Real-time evaluation of blood flow
- Destruction of microbubbles to quantify tissue perfusion
- Safer - no radiation
- Cheaper
- Low dosage needed because microbubbles are very strong
Disadvantages to contrast agents?
- Microbubbles only last a short time in the body
- Microbubbles will burst at low frequencies and high MI
- Reactions to the contrast are possible
Side Effects of Definity?
- Headache/Dizziness
- Flushed
- Nausea
- Chest pain
- Low back or side pain
What can microbubbles be targeted with?
Ligands
Benefit of target contrast agents?
Taken up by the body at a specific area of interest such as inflamed cells or cancer cells
T or F? Contrast target agents are still under pre-clinical development?
TRUE
As bubbles pass through the US window, they act as what kind of reflector?
Strong reflectors relative to blood and tissue
What may contrast agents be used for?
- LV opacification and endocardial border detection
- Lesion detection when echogenicity matches the surrounding tissue
- Lesion characterization - blood flow
- Doppler detection when echoes are weaker
- Small bowel in cases of chron’s disease
