2-D Imaging Physics

Start Studying!

Terms

undefined, object

copy deck

HOw is 2-D imaging created?: multiple pulses are sent out in slightly numerous times
What are the characteristic of transducers?: Shape and # of elements, automatic redirection of sound beams, focusing, shape of image, damaged element display
Which transducer has a single element that is circular, disc shaped (coin)?: mechanical
Which transducer physically moves?: mechanical
The mechanical transducer is ___or ____shaped: sector or fan
Which transducer is motor driven?: Mechanical
Synonym for Mechanica/Fixed?: Conventional/Fixed
The Steering with a Mechanical transducer is ____: mechanical
The focusing of a mechanical is ___, ____, or _____.: fixed, mechanical, or conventional
The mechanical transducer has a ____element or lens: curved
When there is a damaged crystal in the mechanical transducer what happens?: lose entire image
Array means ____: adustable
Array means containing ____elements: multiple
The elements in an array are _____: single PZT cut into pieces
An Array has a channel that consists of an ___, ____, and ___.: element, wire, and electronic circuitry
For a mechanical transducer, there is ____channel for ____element: one, one
What types of array arrangements are there:: linear, annular, convex
Linear arrangenment means:: elements in a straight line
Annular arrangement means elements are in :: a circular ring with common center
A convex array arrangement means that elements are :: bowed or arched line; also called a curved or curvilinear
Which array has a compact small face and no moving parts?: linear phased array
THe linear Phased Array is ____steered and focused: electrically
The Linear Phased Array has ___-____elements that are _____shape: 100-300; rectangular
When there is damaged crystal in the linear phased array there is: erratic focus/steering
In linear phased arrays the electrical spike slope determines:: steering
If pointing beam straight (unfocused beam) the beam is: fired all at the same time
If steering to right or left: phased with billionths of a second delays
the beam former: creates everything
The focusing of Linear Phased Array: BEAM FORMER-- how do crystals excite?: excites outer crystals first then inner crystals later
With Focusing of Linerar Phased Array: _____indicates beam focusing: a curved spike
Focusing of Linear Phased Array: _______will allow focusing and steering to occur simultaneously: slight time delays
Linear phased array: What pattern is not in diagnostic imaging, ?: D-shaped outward spiked pattern; defocused beam
Phased arrays and multifocusing For each focus you use, that is the # of distinct, separate ___: sound pulses sent down that scan line
In phased arrays and multifocusing: The pattern with the most curvature is the: shallowest
IN phased arrays and multifocusing The pattern with least curvature is _____: deepest focus
Dynamic Recieve Focusing During reception the beam can be _____: focused
In dynamic Recieve Focusing Due to time delays depending on depth reflection created they change _____: continuously
Dynamic Recieve Focusing is _____: automatic
Can Dynamic Recieve Focusing by the sonographer?: No
Ring shaped elements with a common center: annular phased array
Annular Phased Array is ____steered: mechanically
Annular Phased Array has multiple ___ ____: focal zones
In Annular Phased Array Inner Ring- _____: shallow focus
Annular Phased Array THe outer ring- ____focus: deep
# of rings= what?: # of pulses down each scan line
Annular Phased Array each ring has different -___: focal zone
ANnular Phased Array THe center, the smaller diameter, the _____the focus: shallower
The Annular Phased Array is ____or _____: fan or sector shaped
Annular Phased Array Damaged crystal-: side to side,loss of image

horizontal loss of image
Large Footprint Rectangular image: linear sequential array
linear sequential array how many elements side by side?: 120-250
In linear sequential arrays Larger than in linear phased (______): 1 wavelength width vs 1/4 wavelenth width
Linear Sequential Arrays _____are fired at a time one after another (sequentially): small groups
Linear Sequential Arrays ___and _____electronically: steer and focus
Linear Sequential Arrays Focusing (_____): transmit; outer are excited first then inner
Linear Sequential Arrays Focusing ( ) -time delays: recieve
In linear sequential arrays the image is _____than transducer: is never wider
Linear Sequential Arrays Damaged PZT?: band dropout from top to bottom
Linear Sequential Arrays Steering of linear sequential is ___shaped: parallelogram shaped
bowed, curve shape large array, 1 wavelength width: convex, curved or curvilinear phased arrays
How many elements are convex, curved or curvilinear phased arrays?: 120-250 PZT elements
Convex arrays has _____focusing: electronic
Convex arrays has ___time delays: grouped time delays
Convex arrays are steered _____: electronically
Convex array has a ____sector: blunted
Damaged crystal with a convex array is: verticla drop out
Combined linear sequential/linear phased: vector arrays
In vector arrays, the electronic slope delays ____: steer
In vector array, ____to ____rectangular strips of PZT: 120 to 250
small footprint; electronic focusing; trapezoidal image flat top: vector array
elevational resolution ; 3rd dimension: slice thickness resolution
slice thickness resolution is ___to imaging plane or above to below imaging plane: slice thickness resolution
____and _____arrays have best elevational resolution (disc shaped): mechanical and annular
Off axis sound beams created by a single element transducer: side lobes
side lobes ___-lateral resolution: degrade
Side Lobes = at depths ___or __than focal zone: = or greater
grating lobes are an ___: array
grating lobes are similar to a: side lobe
produced by array transducer: grating lobe
off axis beams: grating lobe
undersirable: grating lobe
grating lobes ___-lateral res: degrade
True or False? A phased array transducer must have multiple elements: true
T or F An annular array can be focused electronically but must be steered mechanically: True
Which of the following is a rectangular image: linear switched (sequential) array
A fundamental difference between a linear switched array and linear phased array is that linear switched array: has a variable focus and can steer
lowers acoustic impedance mismatch to between the transducer and patient: matching layer
used to decrease spl, improve axial res, increase transducer bandwidth, but decrease transducer sensitivity: backing material
used to shorten spl improving longitudnal res: backing material
malfunction of a single crystal results in a horizontal section of the image having dropout when using: annular
_____transducers can be electrically steered and focused: phased
artifact seen in continous wave imaging wehre the intensity of the beam travels out in some directions not included in the main beam:: side lobes
The matching layer reduces ____at the transducer surface: reflection
In _____arrays, voltage pulses are applied to groups of elements in succession, with no beam steering and adn conventional focusing: sequential (switched)
____arrays are formed by a slab of PZT being cut into concentric rings: annular
_____arrays combine linear phased and linear sequential array technologies. These probes can electronically steer and focus the beam: vector
A single, disc-shaped active element that is physically moved or rotated and can be mechanically steered and conventionally focused describes:: mechanical transducer
The crystal element thickness=____a wavelength: half
shape of a linear probe is: linear
using multiple focal zones does this to frame rate: decreases
If frequency is increased, pulse duration is: decreased
a collection of active elements in a single transducer: transducer array
a few elements but not all fired at exactly same time: linear sequential
is there steering in linear sequential?: no
what is the damaged crystal in linear sequential?: dropout extending from superficial to deep
the patterns focus and steer during transmission: phased array
elements are fired nearly simultaneously: phased array
electronic slope =: beam steering
electronic curvature =: beam transmit focusing

Start Studying!

Deck Info

Number of cards 109

Created By huffmajl