Study guide 12-13 Flashcards
What transducer type is if the crystal is damaged there is no image
Mechanical
What is the typical value for electrical single in phased array transducer
10 nanoseconds ?
What transducer creates a beam that is focused in all planes and all depths
With 2-D array transducers, the sound beams are electronically focused in both the lateral and thickness planes ( used for 3D imaging) pg 191
What is the image shape for a vector array
Flat top/ trapezoid
What transducer has active elements in rings
Annular phased array
which transducer has active elements in straight lines
Linear (page 168 MW)
What is the advantage of a 1 ½ D array transducer ?
has numerous crystals arrange side by side. Has multiple crystals in the up and down direction.
What type of resolution is improved with a 1 ½ D array transducer ?
Improves elevational resolution
Transducer has active elements that are bowed
convex (page 168 MW)
Phased array always means
Adjustable, multifocuses
Liner switch or sequential has what type of steering
Phasing
Drop out from top to bottom what transducer has that type of crystal
Convex&Linear (AL pg 187)
Horizontal /side to side
Annular Phased array
What type of transducer Mechanically steered and fixed and singular focused
Mechanical transducer
The use of more active elements to receive reflections with a great time of flight is called what
Dynamic Aperture(AL????)pg 194
Displaying with both real time and Doppler is called what
Duplex (AL)
The ability to accurately locate moving structures at any particular instance is what type of resolution
Temporal
what will affect the pules in a single image
Number of focal points, sector size, line density
If the imaging depth of view is doubled what happens to the frame rate
it is halved (question 4 page 210 MW)
Sector size that will use fewer pulses
Narrow
What is the consequence from changing the density of one line to three lines
The spatial resolution will be improved which means improve the accuracy of each individual image
What is a frame rate/ how long it takes to create a frame
frame rate is the system’s ability to create numerous frames each second, units Hz (page 198)
Lateral resolution improves which of the following
Multi focus and Dynamic Apperture
what low line density is and what type of imaging it creates
spacing between sound beams which are very wide spaces and it creates a better temporal resolution
What if we have a poor movie quality but a higher image quality
there are multiple focal zones reducing temporal resolution but bettering lateral resolution (page 203 MW)
with line density improves what type of resolution and which one decrease that other type
When line density improves spatial resolution increases, but temporal resolution decreases
If the imaging depth of the scan is 15 centimeters 100 lines what is the number of pluses making up the scan
100(AL) 213 #19&20
Sonographer using a phases array system turned of the multifocus system what action happenes
frame rate increases improving temporal resolution (MW)
if it takes 1/100 sec to create a frame then what is the frame rate (MW)
100Hz (MW)
spatial resolution, who has it? (MW)
Line Density
High line Density = improves spatial resolution
Low line Density = poor spatial resolution
what degrades temporal resolution (MW)
Low Frame Rate deeper imaging multiple focal points wide sector high line density
what limits frame rate (MW)
Sound of speed through the medium
what determines temporal resolution and how is it affected (MW)
Displays a high number of images per second improves temporal resolution
Temporal resolution is reduced when few images are displayed per second
