Rad and Para (Ultrasound)

Echogenicity

the appearance of tissues on ultrasound, based on the ability of the tissues to reflect sound waves. Brightness on B-mode

Anechoic

structure lacking in internal echoes or is echo free, appears dark to black

Hyperechoic

tissue reflects more intensely and is brighter than surrounding tissue (subjective eval of adjoining structures)

Hypoechoic

tissue reflects fewer sound waves w/ less intensity, it appears darker (subjective eval of adjoining structures)

Isoechoic

two structures that have ~ same echogenicity toward each other

Attenuation

The loss of sound wave energy as it traverses the tissue/medium due to absorption, reflection, or scattering

What is a benefit of ultrasound in cardiac studies?

Real-time imaging

What can be done with video recordings from ultrasound?

They can be saved and transferred into a 'cine loop'

What is an advantage of using a diagnostic probe in ultrasound?

The ability to move the probe in any direction required

What safety precautions are required when using ultrasound?

None, as safety precautions for ionizing radiation are not required

What is the basic principle of acoustic principles

production of sound waves by an ultrasound probe (transducer) and the return of that reflected sound wave

What is the most important part of an ultrasound

the elements in the transducer

What are the frequencies in

Hertz (Hz)

What is one mega hertz

MHz

What does higher frequency mean

shorter wl, better resolution, less penetration

What is patient prep

clip hair, skin clean, acoustic gel, standing vs. recumbency, v-trough, darkened room

What is B mode

brightness, pixel is either classified as hyperechoic (bright) or hypoechoic (dark)

What is M mode

motion, a cursor line is set over an area of interest as imaged in B mode. it simultaneously creates b-mode image while displaying the motion of the tissues over a 2-D scale

BART

Blue away, red towards

What is Doppler used for?

To image the flow of blood and other liquids while measuring their velocity.

What is Power Color Doppler used for?

To visualize smaller vessels.

What is Pulse Wave Doppler used for?

To measure flow in even smaller vessels than Power Color Doppler.

What is Continuous Wave Doppler used for?

To measure high velocity blood flow.

Gain

Affect the brightness of the image (mods the wl returning to the transducer

Depth

every type and size of transducer has a set maximum and minimum depth at which it can send and receive sound waves

Time gain compensation

allows the operator to selectively adjustthe gain at various depths

Frequency Selection

allows the operatior to change the frequency w/in range allowed by that probe

Optimization

another option found on many newer machines, a single step-up adjustment that automatically optimizes the settings in order to obtain the best image

What is the purpose of an ultrasound transducer?

To change electrical energy into mechanical energy that penetrates tissues.

What does an ultrasound transducer do with reflected sound waves?

It receives the reflected sound waves and converts them back into electrical impulses.

How does the computer utilize the electrical impulses from the ultrasound transducer?

The computer reads the electrical impulses to create an image.

What is the relationship between transducer frequency and maximum scanning depth?

There is an inverse relationship; as frequency increases, maximum depth decreases.

What is the effect of high frequency on wavelength and resolution?

High frequency results in short wavelength and better resolution.

What is the trade-off of using high frequency in ultrasound imaging?

High frequency provides better resolution but less penetration.

What is a Linear Transducer used for?

It provides an image that is straight down instead of arching, commonly used for equine legs.

What is a Convex Transducer typically used for?

It is used typically in ultrasound imaging.

What is a Microconvex Transducer typically used for?

It is used typically in ultrasound imaging.

What should you avoid to prevent damage to piezoelectric crystals in transducers?

Avoid dropping the transducer.

What type of cloth should be used to wipe off remaining acoustic gel from a transducer?

A dry or water-moistened soft cloth.

What solutions can be used to cleanse contaminated fluids from a transducer?

10% bleach solution, a glutaraldehyde-based disinfectant, or 70% isopropyl alcohol.

What are the clinical applications in bovine and ruminants?

Reproductive work including follicle detection, pregnancy examination, and addressing reproductive difficulties.

What are the clinical applications in equine medicine?

Sports medicine and reproductive health.

What is a clinical application in porcine medicine?

Measurement of back fat levels in animals destined for meat production.

What is notable about clinical applications in small animals?

The list of possible applications seems to be almost endless.

Comet Tail

Reflection of sound waves of gas, air, or metal

Edge Shadowing

Reflraction off a filled curves surface (Bladder)

Acoustic Enhancement

Beam traveling at dif speeds due to density

Reverberation

repeated reflection of sound waves off gas

Acoustic Shadowing

where something very dense stops the wave so nothing under it is imaged

Sidew Lobe

usually seen in fluid-filled anechoic structures where there is a divergent adjacent density present