Chapter 10 Flashcards
Axial and lateral resolution (30 cards)
T or F
Resolution is the ability to create accurate images
True
The ability to distinguish 2 structures that are close to each other, front and back, parallel to or along the beam’s main axis
Axial resolution
Can axial resolution be adjustable
no
Shorter or longer pulses improve the axial resolution
Shorter
Axial resolution is related to
SPL, Pulse duration
formula for axial resolution
SPL / 2
Synonyms for axial resolution
Longitudinal
Axial
Range
Radial
Depth
A short pulse is created by what?
Less ringing (Damping Material)
Higher frequency
Better axial resolution is associated with what?
Short SPL
Short PD
Short Wave Length
Less no of cycles(less ringing)
Lower Numerical Values
Higher Frequency(shorter wavelength)
The minimum distance that 2 structures are separated by side to side or perpendicular to the sound beam that produces 2 distinct echoes
Lateral Resolution
Synonyms for lateral resolution
LATA
Lateral
Angular
Transverse
Azimuthal
Unit for Lateral Resolution
mm
Lateral resolution is determined by the width of the sound beam, narrower beams have better resolution (T or F)
True
Lateral resolution changes with what?
Depth
Beam diameter changes with what?
Depth
Lateral resolution is equal to what
Beam diameter
As the beam varies with depth what happens to the lateral resolution?
it widens
Lateral resolution is best at where?
Focus, where the beam is narrower
Which frequency improve both axial and lateral resolution?
Higher frequency
Fixed focusing is also known as
Conventional or mechanical focusing
Effects of focussing
- Beam diameter in near field and focal zone is reduced.
- Focal depth is shallower.
- Beam diameter in the far zone increases.
- Focal zone is smaller.
Beam divergence is determined by what?
Diameter of ceramic and frequency of sound
Focal length is determined by what?
Diameter of ceramic and frequency of sound.
Lateral resolution is determined by what?
Beam width
