RESOLUTION Flashcards
THREE ASPECTS OF RESOLUTION
- Spatial Resolution
- Temporal Resolution
- Contrast Resolution
The ability of an imaging system to differentiate between structures, images, or events and display them as a separate entity.
resolution
The ability to display two structures situated close together as separate image.
spatial resolution
components of spatial resolution
axial and lateral
Ability to display small targets along the path of the beam as separate entities.
axial resolution
Resolution along the axis of the beam
axial resolution
axial resolution aka
longitudinal resolution
latera resloution aka
azimuthal resolution
Depends upon the width of the ultrasound beam (best where the beam is narrowest)
lateral resolution
formula for axial resolution
Spatial pulse length / 2
unit of axial resolution
mm
Ability of the imaging system to differentiate between tissues and display them as different shades of gray.
contrast resolution
Ability of the imaging system to display events which occur at different times as separate images.
temporal reso
important to echocardiography
temporal reso
temoral reso is determined by
frame rate
no. of images per second
frame rate
two types of planes for hadling the tranducer
longitudinal and transverse
longitudinal on the left and right sides are the patients
superior and inferior
transverse on the left and right sides are the patients
right and left
Displays images in black and white combinations only.
bistable scanninga
a mode stands for
amplitude mode
A single dimension display consisting of a horizontal baseline. This baseline represents time and or distance with upward (vertical) deflections (spikes depicting the acoustic interface)
a- mode
used in opthalmology
a - mode
b mode stands for
brightness mode
A two-dimensional display of the ultrasound.
b-mode
The A-mode spikes are electronically converted into dots and displayed at the correct depth from the transducer.
b-mode
b-mode is aka
b-scan or gray scale sonography
m - mode aka
motion mode
Used to visualize things that are physically moving. The motion occurring in a one dimensional scan line is displayed on the vertical axis over time on the horizontal axis
m-mode
This mode is most commonly used in the evaluation of cardiac valves and fetal heart activity
m - mode
uses the frequency shift of sound waves to measure velocity, typically blood
Doppler
most common uses of doppler
o Color flow doppler CFD
o Power or Angiodoppler
o Spectral doppler (pulsed and continuous wave)
how much distance into the body the image displays in the far field.
depth
Used to adjust the size of the image so that organs and adjacent structures or regions of interest are equally well visualized.
depth
hihger depth = – magnification
higher
Is a knob that adjust the overall UTZ echo signalgain
gain
gain ↑ = ___ reflection =__ brightness
high and high
set up as a column of sliding knobs or may be adjusted for near and far gain.
time gain compensation
Allows selective control of gain at different depths
TGC
allows for the magnification of one area on the screen
ZOOM
This control is used to magnify structures of interest. Various capabilities as provided by the manufacturer.
KEYBOARD
concentrates the sound beam into a smaller beam area than would exist otherwise. This area of focus is where you will obtain your best images.
FOCUS
It can be found on the monitor (arrow), on the vertical millimeter scale
FOCUS
Determines how many shades of gray are demonstrated on an image.
DYNAMIC RANGE
gives fewer grays and increases contrast
DYNAMIC RANGE
Increasing dynamic range gives a wider range of ___ and decreases ____
GRAYS AND CONTRAST
This control captures a single frame from a dynamic image
FREEZE
allow the operator to review a sequence of acquired images
CINE LOOP
Available to measure distances
caliper
Images may be captured for archival or export
acquiring images
