Operator controls

Knobology

is the study of knobs or the functionality of controls

Monitor

Displays the ultrasound image with 2D, color and spectral doppler

Which part is near field and which part is far field

near field is on top and far field is on the bottom

power (dB)

Amplifies the sound into the patient; controls brightness

Determines the strength of the pulse sent into the human body

when the transmitted pulse is strong, the echos returning will be brighter

Generally, the preset is sufficient for imaging

ALARA

As low as reasonably achieveable

Low output power - high receiver gain

when the image is too bright

you can reduce the power (output)*

sector

Linear array

curved array

low frequency =

high pentration

high frequency =

low pentration

high frequencies

superficial structures

better resolution, but less penetration

low frequencies

deep structures

not as good resolution, but better penetration

Depth

Allows for adjustment of the image size

properly display body part being imaged

relational anatomy should be included

Harmonic imaging

frequency of the ultrasound pulse, which is twice the transmitted frequency, to create images. This technique improves image quality by enhancing contrast and resolution and reducing noise and artifacts,

overal Gain

“volume” control

Amplify sound

controls overall brightness of an image

time/depth gain compensation

Helps to create a uniform image by adjusting uneven brightness regardkess of depth

shallower structures will be brighter and deeper structures will be darker

compensate for attenuation that occurs with increasing depth

uses slide pods to control gain at different depths in specific regions of the image

Gain / TGC

should be adjusted so that tissue and its interfaces are recognizable

different tissues have different echo densities

Fat

Medium level gray; hyoechoic

different tissues have different echo densities

Fibrous tissue, ligaments, and skin

hyperechoic compared to fat

different tissues have different echo densities

calcifications

Markedly hyperechoic compared to fat

Fat

Medium level gray; hypoechoic

Muscle

Moderately hypoechoic compared to fat

Malignant solid nodules

midly to markedly hypoechoic compared to fat

simple cysts

markedly hypoechoic compared to fat and anechoic

Focal zone poition and number

tightest part of the ultrasound beam \beam is hourglass shaped

Focal zone is placed at or ?

below area of interest

focal zones

it will slow frame rate or image acquisition, but give bettter detail and resolution

the more focal zones used

the slower the frame rate

What is Dual image

displays 2 images side by side

image width

narrows swctor width

improves lateral resolutions

edges of masses are sharper

increased frame rate

able to steer the beam 90 degrees to structure

Improved reflection!

titnt/color maps - b-mode

colorization transforms the b-mode image from standard shades of gray to an alternative color display

Gain maps

Gray maps will add other levels of gray to the factory presets already in your machine

it provides subtle changes to the near or far fields

other maps change the shade of gray altogether

Dynamic range

Reflects the number of shades of gray that are displayed on the image

Also known as long compression

it is a function that varies to accommodate the range of intensities from the larhest to the smallest echo that the systen can handle

Low Dynamic range =

high contrast

less shades of gray

more blacks and whites

high Dynamic range =

low contrast

more shades of gray

allows for demonstration of subtle tissue contrast

contrast resolution

it is directly affected by the dynamic range setting on the ultrasound unit

if the dynamic range setting is set too low, the image contrast can make a solid structure appear cystic

is the dynamic range is set to high there is little contrast and a subtle mass may blend in with surrounding fat lobules

eedge enhancement

also known as sharpnes

a filtering technique that sharpens the image by identifying and enhancing the interfaces or boundaries between structures

leads to “crisper” images

smoothing

removes speckle noise from the ultrasound images

adjusting the image persistence causes individual frames of the scan to linger

persistence blends the individual frames with the images in the successive frames this creates — to the ultrasound image

increasing persistence will smooth the image but

reduces the system frame rate

decreasing persistence creates a more

pixilated/speckled image

what is the right way to zoom

is right zoom while the image is live

pre - processing

controlled by sonographer

altering data prior to it entering the machine

permanent and cant be changed

controls that cant be changed

post processing

controlled by sonographer

altering data after it enters the machine

these changes are not permanent

controls that can change a frozen image

read magnification

color maps

contrast variations

soft or lower contrast maps

sharper or higher contrast maps

controls that cant change a frozen image

TGC

write magnification

log compression

Doppler: detects movement of

RBC’s

color box

detects flow within region of interest (ROI)

size

should just contain the area of interest

too bigh = slows down frame rates

color gain

similar to b mode gain

SD - spectral doppler

Provides velocity or frequency shift information of blood flow on a graph

uses sample volume gate to obtain information

vascular: use an angle to flow

carfiac; no angle used

SD Gain

similar to B mode and CD gain

M-mode motion/time

information displayed runs along the cursor

depth is the vertrical axis

time is the horizontal axis

the echo brightness is related to the strength of the ref;ected echos

blood filled cavities should have no echoes

Freeze key

stops or starts the display image

allows for image capture

unfreezing returns to real time image

opportunity to annotate image, perform calculations store image

Trackball

guides cursor on the screen

can move the image through the different cycles imaged

positions measurement calipers

change size of scan area for zoom and color box size

cine loop

capture several images and sores them as a clip

image store / print

image capture button that saves image to hard drive

keybored

controls like annotation or comments on/off erase/clear.clear screen

backspace

new patient key /end

current patient

annotation

body marker labes are used for labeling anatomical structures

entering patients info

patient data is obtained from electronic medical records (EMR) and radiology info system (RIS)

ris

intergrates with the emr scheduling digital dictations and worklists

using the ultrasound system

select appropriate exam preset and transducer

exam preset

established baseline for that particular exam

step two transducer

high frequency transducer: small parts, thin patients, superficial structures; when detail is important

low frequency transducer; abdomen, OB/gyn, large patients; when penetration is needed

step 3 Gel application

gel is has inert properties

provides a media for sound waves to enter body

getting the image

1.adjust depth

2.Adjust focal zones: at or below area of interest

3.transducer frequency

4.adjust overall gain

5.adjust TGC

6. other technical adjustments

how to produce the best image possible

1.strong knowledge of anatomy and pathophysiology

2.patience and perseverance

3.understanding ultrasound physics

4. familiarization of the sonographic machine and controls