Reject Overview
Adjustable
Only weak signbals affected
Strong signals remain unchanged
Weak echoes appear or are eliminated from image
CRT
Monitor
Displays the information from returning echoes
2 user controls
brightness
contrast
Output Power
vs
Reciever Gain
patient exposure to sound energy is affected by output power NOT by reciever amplification
Output Power SUmmary
changes brightness of image
alters signal to noise ratio
alters patient exposure
bioeffect concerns
decrease this first if image too bright
Reciever Gain Summary
Changes brightness of entire image
does not affect signal to noise ratio
does not change patient exposure
NO bioeffect concern
increase this first if image is too dark
Persistance
frame averaging that allows echo information to be accumulated over time
Persistence Increase
subtle texture differences will be enhanced
Persistence Decrease
allows user to evaluate moving structures more easily
Zoom/Magnification
allows image magnification by increasing the pixal size
2 types
Read
Write
Read Zoom
occurs after the image is stored
number of pixals or scan lines is the same as original image
Can appear blurry
Write Zoom
Occurs while active scanning
box is placed on screen and the area seen within can be expanded to fill screen
number of pixals and scan lines remain the same
image is not degraded
Calipers
Markers available to measure distance
linear
ellipsoid
trace
Annotation
allows the labeling of the image
may be keyboard or preprogrammed keys
may be voice activated
Dual image
allows the screen to be split in order to show 2 views of an image or compare anatomy of abnormal side to normal side
