Clinical Safety
principle used to reduce biological effects in humans and the fetus
What is ALARA principle
Propagation speed of soft tissue
What is 1540 m/s
This layer reduced the impedance difference between the crystal and the skin
What is the matching layer
In a brightness-mode display, the y-axis represents
What is the penetration depth
An ausculatory consequence of turbulent flow
What is bruit
Lowest intensity value in pulsed-wave ultrasound
What is SATA
Propagation speed through a medium is determined by
What is the density and stiffness of the medium
Decrease in imaging depth improves which resolution
What is temporal resolution
Frame rate is determined by penetration depth and
What is the propagation speed of the medium
Normal respiratory variations in venous blood flow
What is phasic flow
2 types of cavitation
What is transient and stable
The length of a pulse from beginning to end
What is spatial pulse length
Another name for lateral resolution
What is Angular, transverse, and azimuthal resolution
Term used to describe a volume picture element
What is voxel
Observed frequency changes in moving structures
What is the Doppler effect
Pressure changes in soft tissue most likely result in
What is cavitation
When sound wave strikes a large, smooth surface at 90 degrees
What is specular reflection
Distance from the face of a focused transducer to the point of spatial peak intensity
Focal length
Which resolution is most related to pixel density
What is spatial resolution
Nyquist limit is equal to
1/2 of the pulse repetition frequency
Ratio of acoustic power produced by the transducer and the power required to raise tissue temperature by 1 degree celsius
What is thermal index
Half value layer is equal to an intensity reduction of
What is 3dB
During transmission, diagnostic ultrasound transducers convert electrical energy into
What is thermal energy
Shadowing and enhancement are a result of what type of imaging artifact?
What is attenuation
What converts Doppler shift information into a visual spectral display
What is the fast Fourier transform