Flashcards in Transducers Continued Deck (31):
What controls the electronics that create the patterns of slope (steering) and curvature (focus)?
How does the beam former create slope and curvature?
incredible short time delays to create these patterns
Does the beam former do its job in the transducer or in the system?
in the system
The beam former works with .....
the electrical voltage
What shape does a sector transducer make?
with a sector transducer how do the elements fire?
all at the same time
electronic focusing and steering (beam former)
How does a Vector array work?
combines linear sequential and linear phased
trapezoidal shape - flat top
multiple focal points - phased array
What is dynamic focusing?
reception or receiving focus (multizone)
transmission or transmitting focus (multizone)
Why is dynamic focusing important?
It improves the image
What is dynamic aperture?
more crystals listening
form of electronic focusing
focusing during reception
varying the number of elements to listen
improves LATERAL RESOLUTION
What helps with focusing?
What is a multidimensional array?
two dimensional array of small transducer elements
**its a MATRIX***
What transducer makes a thinner slice/narrower beam?
improves elevational resolution
more elements side to side than up and down
of the arrays what are the different kinds of construction?
Of the arrays what are the operations?
sequencing or switched
what are the different kinds of spatial resolution?
What is axial resolution?
longitudinal, axial, radial, range, depth
1/2 spatial pulse length
the smaller the better
What is lateral resolution?
lateral, angular, transverese, azimuthal
related to beam width... no math - just whatever the beam width is that is the lateral resolution
What is elevational resolution?
section thickness, partial volume, slice thickness
takes the beam and it doesn't appear as flat...the thickness improves the picture
creates a thicker slice of the image
What is detail resolution?
disc shaped crystals
elevation resolution equal to lateral resolution with disc shaped crystals
reduces section thickness artifacts
What is volume imaging?
3-D and 4-D imaging
What is Keepsake Ultrasound?
3-D and 4-D imaging for fun....womb with a view type places
What are side lobes?
created by a Single element transducer
extend off the main beam
degrade lateral resolution
What is a Grating lobe artifact?
found in Array transducers
degrade lateral resolution
reduce image quality
How do you eliminate Side lobes and Grating lobes?
variable or dynamic aperture (open and closes the beam)
what is apodization?
alters electrical spike voltages
improves Lateral resolution
what is subdicing?
sub elements - improves lateral resolution
What improves lateral resolution?
variable or dynamic aperture (open and closes the beam to how it is needed)
go to ovel, eldeman, and kremkau
learn all different kinds/details about the transducer
compare curved arrays and annular arrays
convex not produced
firing groups sector
ABD concentric circles
OB/GYN mechanically steering
electronic focus electronic focus