Knobology Flashcards
Multihertz is what (what in our machine)
Change frequency without changing probe
On our machine is gen pen res
Harmonics (what/on when)
Sends out a frequency and receives double that frequency when echoes return
On most of the time
Transmit power (what/improves)
Adjust intensity of US beam transmitters into the patient (increases echo without increasing noise)
Improves signal noise ratio (SNR) and enhance sensitivity
Gain represented in ______
Decibels
Will gain and TGC improve the signal to noise ratio (SNR)
No
Always reset ____ before selecting preset
TGC
Multiple foci (what/result)
More than one focus
Reduces frame rate significantly
Dynamic range
Form of compression that reduces the number of shades of gray to increase contrast
Decrease dynamic range = _______ contrast
Increase
Sector width (what probes/what/improves)
With curved linear and echo probes
Reduce the field of view by firing less lines
Improved frame rate
Persistence(aka, what)
Frame averaging
Helps with noise reduction by applying temporal averaging to individual pixels
Ex. Show 3 frames and average together
Increasing the persistence will ______ the frame rate and is not used for ____ applications
Frame rate
Cardiac
Write zoom (what/associated with)
Magnifies the image before it is written to the memory (zoom on phone take picture)
Improved resolution
Read zoom (what, associated with)
Magnifies the image after image is committed to systems memory
Associated with Zoom resolution lost (take picture then zoom)
Maps (what, when can it be done)
Redistributes the shades of gray displayed so that emphasis can be give to certain values
(Brighten low level or ignore echoes above a threshold)
Be done before or after image is frozen
Video invert
Bone= black
Fluid= white
pre-processing vs post-processing
anything that can be done before the image is committed to memory
vs
controls are applied to the image after its frozen
compound imaging
combo of beam steering and frame averaging that can improve the SNR and help eliminate artifacts
panoramic imaging
if area of interest is larger than transducer face
Which of the following controls; TGC, write zoom and depth, are considered both pre-processing and post-processing controls?
TGC
Is the angle correction for Doppler a pre-processing or post-processing control?
both
Explain colour priority
Priority is used to optimize colour fill-in when performing colour Doppler in the presence of increased gray scale noise. An increase allows more colour information to be displayed over gray scale data.
What control would improve the return of the Doppler signal when the insonating angle is close to 90?
The steer function of the machine, when used appropriately, will help decrease the insonating angle of the sound to improve the Doppler signal return.
