Deck 17: Abdominal Applications of Ultrasound Contrast Agents

Question 1

Vascular ultrasound agents enhance Doppler flow signals by:

A) increasing the velocity of blood flow.
B) adding more and better acoustic scatterers to the bloodstream.
C) increasing the number of red blood cells in the vessel being evaluated.
D) decreasing the speed of sound through tissues.

Answer 1

B

Question 2

Depending on the clinical application, vascular UCAs may be administered via:

A) intravenous bolus injection.
B) oral ingestion.
C) intravenous infusion.
D) albumin.

Answer 2

C

Question 3

Tissue-specific ultrasound contrast agents can be considered to be:

A) molecular-imaging agents.
B) first-generation contrast agents.
C) mechanical-imaging agents.
D) oral-contrast agents.

Answer 3

A

Question 4

When insonating microbubble-based UCAs, the acoustic pressure present within the acoustic field:

A) has no effect on microbubbles.
B) can have a detrimental effect on the contrast microbubbles.
C) usually results in increasing the microbubble size.
D) usually results in the creation of more microbubbles.

Question 5

Hepatic cavernous hemangiomas demonstrate only peripheral enhancement during the:

A) arterial phase.
B) portal venous phase.
C) late vascular phase.
D) None of the above

Question 6

In harmonic-imaging mode, the echoes from the oscillating microbubbles have a:

A) low signal-to-noise ratio.
B) low transducer frequency.
C) equal signal-to-noise ratio.
D) high signal-to-noise ratio.

Question 7

Evaluation of a patient with known cirrhosis often demonstrates a(n):

A) reduced portal venous flow with an increase in hepatic artery flow.
B) increase in portal venous flow with an increase in hepatic artery flow.
C) reduced portal venous flow with a reduction in hepatic artery flow.
D) increase in portal venous flow with a reduction in hepatic artery flow.

Question 8

Most of the research and development of ultrasound contrast agents (UCAs) has centered on creating agents that can:

A) enhance the detection of stationary blood.
B) be administered by intra-arterial injection.
C) be administered intravenously.
D) enhance the detection of tumors in solid organs.

Question 9

Ultrasound contrast agents have shown the potential to improve the accuracy of hepatic sonography including:

A) enhanced detection of hepatic masses.
B) enhanced characterization of hepatic masses.
C) improved detection of intrahepatic and extrahepatic blood flow.
D) All of the above are characteristics

Question 10

For a vascular ultrasound contrast agent to be clinically useful, it should:

A) be nontoxic.
B) have microbubbles that are small enough to traverse the pulmonary capillary beds.
C) be stable enough to provide multiple recirculations.
D) have all of the above characteristics.

Question 11

The mechanical index (MI) uses:

A) low acoustic output power.
B) low transducer frequency.
C) an increase of dynamic range.
D) high acoustic output power.

Question 12

Induced acoustic-emission effects are independent of:

A) Doppler shifts.
B) microbubble size.
C) contrast motion.
D) All of the above

Question 13

The first ultrasound contrast agent to receive FDA approval was used in:

A) biopsy procedures.
B) vascular sonography.
C) echocardiography.
D) general sonography.

Question 14

In the early arterial phase, using tissue-specific contrast agents, focal nodular hyperplasia can have a similar appearance to a:

A) hepatic cyst.
B) hemangioma.
C) hepatocellular carcinoma (HCC).
D) hepatic abscess.

Question 15

Which of the following vessels are the first to demonstrate contrast enhancement in the liver?

A) Hepatic veins
B) Hepatic arteries
C) Right portal veins
D) Left portal veins

Question 16

The rupture of microbubbles results in random:

A) tissue enhancement.
B) Doppler shifts.
C) wall definition.
D) enhanced time.

Question 17

The microbubbles of tissue-specific UCAs are:

A) significantly larger than red blood cells.
B) significantly larger than liver cells (hepatocytes).
C) taken up by or have an affinity for specific tissues.
D) toxic to the targeted tissue.

Question 18

When using ultrasound contrast agents, a lesion that gets progressively echogenic over time is most likely:

A) focal nodular hyperplasia.
B) hemangioma.
C) hepatocellular carcinoma.
D) adenoma.

Question 19

The detection of flow in the hepatic capillaries is identified in the ___________ phase.

A) arterial
B) early vascular
C) portal venous
D) late vascular

Question 20

Several reports have described the contrast-enhanced sonographic appearance of hepatocellular carcinoma as having intense enhancement in the _____________ phase.

A) late vascular
B) portal venous
C) early arterial
D) late arterial

Question 21

To aid in contrast-enhanced imaging equipment, manufacturers have begun to incorporate __________ into their systems to reduce microbubble destruction.

A) harmonic imaging.
B) MI.
C) intermittent imaging capabilities.
D) frame one imaging.

Question 22

When the microbubble is destroyed:

A) vessels are easier to detect with color Doppler.
B) contrast enhancement is no longer provided.
C) contrast enhancement is increased.
D) vessels are easier to detect with gray-scale harmonic imaging.