Knobology Flashcards
Determines the strength of the pulse transmitted into the body.
Returning echoes are stronger when the transmitted pulse is stronger; thus the image is brighter,
displayed as decibels (dB) or percent maximum
Power output
Allows the sonographer to amplify or boost echo signals. Is done to compensate for the attenuation of sound in deeper tissues
Acoustic exposure to the patient remains unchanged when the receiver gain is increased
it it is set too high, artifactual echo noise will be displayed throughout the image
Gain
Allows the sonographer to amplify receiver gain gradually at specific depths.
Sometimes referred to as depth gain compensation(DGC)
Depth of interface is determined by the amount of time it takes for transmitted sound pulse to return to the transducer
TIme Gain Compensation
Allows transducer to focus transmitted sound at different depths.
As multilevel focusing is used, frame rate decreases
Focal zone
Allows the sonographer to adjust the depth and width of an image.
Larger or deeper field of view causes the frame rate to decrease.
Depth is displayed in centimeters on the side of the image
Width adjusts horizontal axis of the image and may be used to reduce side lobe artifacts
Field of view
Eliminates both electronic noise ans low-level echoes from the display. Done internally in computer
Reject
Range of input signal levels produces noticeable changes in the output of the device
Dynamic range
Generally produces high contrast. Echocardiography and peripheral vascular
Low dynamic range
Shows more shades of gray and lower contrast.
Abdominal and obstetrics
High dynamic range
Write zoom, increases detail
Zoom
Captures the image, must be without motion, patient holding breath
Freeze
Increase (down PRF) decreases (up PRF)
Depth
Color box used, you determine angle of box
CF= Color Flow Doppler
Cursor and sample volume used, gate (size of sv), angle
PW= Pulsed Wave Doppler
Blind, no image. Positive/ negative flow by sound
CW= Continuous wave Doppler
Divides image into two screens, rt and lt, you scan, placement
L R (Dual Screen)
Calipers used to measure distance, velocity, resistivity indexes
Measure
Used for labeling each image, text typing
Comments
Can clear measurements or comments
Clear
“Sets” caliper so additional caliper can be activated for measurements
Set
Can narrow field of view, increases PRF= increases image quality
Scan area
Moves calipers, color box, sample volume/ cursor, controls zoom box size
Track ball
Send certain sound waves at (ex) 4MHz, “receijves” only 8MHz returning
Harmonics
Characterature of body, used on image page for location instead of text
Body pattern
Used to measure circular objects-HC and AC, ex
Ellipse
M-mode and Doppler cursor
M/D cursor
Controls number of, and position of focal zones
Focal zone/ Depth
Decibels, gray scale control
up dB= up Grayscale
down dB=down grayscale (more contrast)
dB
Programmed soft touch keys
Annotations
Start of new exam, new patient. enter pt information here
PT ID
On keyboard, deletes entire word at a time
Word delete
