Ultrasound Flashcards
1
Q
What types of resolution and what factors affect each type?
A
Axial - wavelength
Lateral - width of beam
Elevation - slice thickness
2
Q
What types of artefacts do you get in ultrasound?
A
Beam width
Velocity
Beam dispersion
Reverberation
Mirror image
3
Q
What factors affect Doppler frequency shift?
A
Frequency, blood velocity, angle between us beam and direction of flow. Speed is constant
4
Q
What are the patterns on Doppler for various stages of CSA narrowing?
A
Less than 50 percent - moderate spectral broadening
More than 50 - complete spectral broadening
More than 75 - turbulence
5
Q
Name Doppler artefacts.
A
Sample size
Velocity information
Frequency aliasing
Wall filters
Colour artefacts
6
Q
A
