The crystal is destroyed, and there is no image. What type of transducer is this?
What is the typical value for electrical single in phased array transducer?
What transducer creates a beam that is focused in all planes and all depths?
annular phased array
What is the advantage of a 1 1/2 dimensional array transducer?
thinner beams with improved sliced thickness
What type of resolution is improved by using a 1 1/2 dimension transducer?
What is the image shape for a vector array?
flat top sector (trapezoid)
What transducer type has active elements arranged in rings?
What type of transducer has active elements alligned in a straight line?
What transducer has active elements that are bowed?
Phased array always means what?
Linear switch (sequential) has what type of steering?
Drop out from top to bottom, what type of transducer will have that from a malfunction?
linear sequential (switched), convex sequential, 3D/4D
What type of transducer has horizontal, side to side, drop out from a malfunction?
Which transducer is mechanically steered and fixed and singular focus?
The use of more active elements to receive reflections with a greater time of flight is called what?
Displaying both real time and Doppler at the same time is known as?
The ability to accurately locate moving structures at any particular instance is referred to as what type of resolution?
What determines temporal resolution and how is it affected?
It is determined by frame rate
high frame rate (high # of images) improves temporal resolution
Which factors limit frame rate?
speed of sound in the medium
What will affect the pulses in a single image?
number of focal points
If the imaging depth of view is doubled, what happens to the frame rate?
Frame rate decreases and degrades temporal resolution
What will degrade temporal resolution?
multiple focal points (improves lateral resolution)
high line density (improves spatial resolution)
What sector size uses fewer pulses?
What's the consequence of an action from changing the density of one line to three?
tightly packed lines
more pulses per frame
lower frame rate
low temporal resolution
excellent spatial resolution
What is a frame rate, and how long does it take to create a frame?
Tframe= # of pulses x PRP
system's ability to create numerou frames each second
When does lateral resolution improve?
What is low line density and what type of image does it create?
line density-space between the sound beams
low line density- lines are spaced far apart, fewer pulses per frame, shorter Tframe, higher frame rate, high temporal resolution, poor spatial resolution
What if we have a poor movie quality but a higher image quality?
wide field of view
high line density (very tightly packed scan lines and small gaps)
With line density, which improves what type of resolution and which decreases the other?
low line density- high temporal resolution, poor spatial resolution
high line density- low temporal resolution, excellent spatial resolution
If the imaging depth of the scan is 15cm and there are 100 lines of image, what is the number of pulses making up the scan?
Sonographer using a phased array system turns off the multi-focus system. What is the most likely consequence to happen?
temporal resolution improves
What is spatial resolution and which line density improves it?
spatial resolution is the details in an image
High line density= excellent spatial resolution