Chapter 9, 10 & 11 Flashcards
Wider transducer diameter equals ______ focal depth
Higher
Smaller transducer diameter equals ______ focal depth
Less
High frequency transducer equals_____ focal depth
Higher
Low frequency transducers equal ______ focal depth
Shorter
High frequency transducers equal _______ divergence
Less
Low frequency transducers equal____ divergence
More
Higher transducer diameter equals_____ divergence
Less
Smaller transducer diameter equals______ divergence
More
Axial resolution other names
Longitudinal, axial, range, radial, depth (LARRD)
Axial resolution is the ability of the system to display two structures that are______ to the sound beam
Parallel
Is axial resolution adjustable?
No
Lateral resolution other names
Lateral, angular, transverse, azimuthal (LATA)
Lateral resolution is the ability of the system to display two structures that are _____ to the sound beam
Perpendicular
B-mode stands for
Brightness
A-mode stands for
Amplitude
On A-mode the x-axis represents the:
Depth
On A-mode, the y-axis represents the:
Amplitude
On B-mode the x-axis represents the
Depth
Z-axis in b-mode indicates what
Different shades of gray
On M-mode, the y-axis represents the
Depth
On m-mode the x-axis represents the
Time
Far zone is also known as
Fraunhofer zone
Near zone is also known as
Fresnel zone
The width of sound beam at the focus is _____ the sound beam as it leaves the transducer
Half
What are other names for spherical waves
Diffraction patterns or
Huygens wavelets
The interference of many spherical waves create the shape of the sound beam. What principle explains this
Huygens principle
Axial resolution improves with
Shorter pulses
Axial resolution is determined by_______ and remains constant
Spatial pulse length
Lateral resolution is best with
Narrowest beam
Lateral resolution changes with
Depth
Lateral resolution is best at
Focus
High frequency improves lateral resolution in the far field only, explain why
Less divergence
Which one is better axial resolution or lateral, and understand why
Axial, because the beam is shorter than it is wider
What are the three methods of focusing
Electronic (phased array), external and internal (fixed)
