quiz 7

Which of the following Doppler displays cannot determine flow direction?

Which of the following Doppler displays cannot determine flow direction?

Power

The difference between the emitted frequency and the echo frequency returning from a moving scatterer is called ________.

doppler shift

Doppler measurements are not reliable at Doppler angles greater than________ degrees

60

This waveform indicates which of the following criteria?

Spectral Broadening

Vertical thickening  of the spectral tracing (window) is called ________.

spectral broadening

The fast Fourier transform processes the Doppler ________.

spectrum waveform

Motion toward the transducer demonstrates ________.

a positive Doppler shift

The Doppler shift is directly proportional to the blood flow speed

False

Higher operating frequencies produce larger Doppler shifts

True

In pulsed Doppler imaging, the operator of the ultrasound system controls the size and location of the sample volume.

true

This picture is taken using which Doppler technique?

Power doppler

What type of blood flow demonstrates layers of fluid sliding over each other?

laminar

Based on Poiseuille's law, all of the following provides/determines resistance to blood flow except ________

plasma proteins

What is the arterial pressure in the carotid artery of the neck of the supine normal person?

120 mmHg

Normally, what happens to venous flow in the legs during inspiration?

decreases

All of the following occur during expiration except:

Abdominal pressure increases

The decreased pressure in regions of high flow speed is called ________.

Bernoulli effect

The amount of blood passing a point per unit of time defines ________.

volumetric flow rate

Which 2-D imaging parameter is reduced with simultaneous addition of color Doppler?

Frame rate

In color flow imaging, which technique tracks the displacement of a group of red blood cells as it moves through the sound beam?

Autocorrelation

What is the direction of flow in this image?

Indeterminate

What is the Nyquist limit if a pulsed-wave Doppler instrument has a pulse repetition frequency of 16 kHz?

8

An increase in which parameter will improve the accuracy of velocity measurement with autocorrelation?

Packet size

Which operator control can be used to adjust the image contrast?

dynamic Range Compression