Random
What units is Frequency measured in?
Hertz (Hz)
Optimal doppler readings are seen between ____ and ____ degrees.
30
60
With continuous wave transducers, one element is always _______________ and the other is always ___________.
Sending
Listening/Receiving
The operator should make the sample volume gate _______ to increase accuracy of the reading.
Small
The area beneath the peak of the spectral trace is the ________.
Spectral Window
The doppler shift is created by the difference between __________ and ____________.
Transmitted Frequency
Received Frequency
Angle correction errors are more critical as the doppler angle approaches ____ degrees.
90
This control removes low frequency doppler signals.
Wall filter
Doppler ultrasound is reliant on _________ scatterers.
Rayleigh
What kind of blood flow creates spectral broadening?
Doppler frequency is related to ultrasound frequency in what way?
This type of ultrasound instrument has only 2 elements.
Continuous Wave
What point is the most sensitive for signal detection with continuous wave doppler?
The point at which the beams intersect.
_________ instruments allow the sonographer to scan in B-mode and doppler simultaneously.
Duplex
To prevent aliasing the PRF must be ____________________________.
At least 2x the doppler frequency
Maximum frequency is seen at this angle.
0 degrees
The amplitude of the transmitted beam is controlled by which setting?
Power
________ frequency beams are subject to more attenuation.
High
Normal flow through an average sized vessel is described as _________.
Laminar
Color flow and Pulsed Wave doppler aliasing can be corrected by doing what THREE things. (In order)
Increase the scale
Decrease the baseline
Change the transducer
No frequency shift is seen at this Cosine.
0
This control adjusts the amount of amplification applied to the received echoes.
Receiver Control
Pulsed doppler allows the sonographer to select signals from a specific ___________.
Depth
What does the Fast Fourier Transformer do?
Converts the doppler signal to a spectral readout.
What are the two methods used for angling the bean with a linear transducer?
An angled offset tool
Beam steering