Reflection
Ultrasound imaging is based on echoes of transmitted sound waves.

The more a structure reflects the sound waves, the whiter the structure appears on the screen.

An-, hypo- and hyperechoic
Some structures are great reflectors of ultrasound waves and appear bright white (hyperechoic) on the ultrasound screen.

Other structures reflect only little and appear hypoechoic (gray).

Air, fluid, blood all appear anechoic (black) which means there is no reflection at all.

Three types of transducers are used in basic emergency ultrasound:

A systematic approach will facilitate successful scanning:

Imaging
Ultrasonography is an imaging method based on ultrasound.

Ultrasonography uses the impulse-echo principle of generating and emitting short pulses of ultrasound that are reflected at tissue interfaces and subsequently recorded by the receiver.

The reflected sound wave is essential for the production of the ultrasound images.

Frequency
The frequency of a sound wave is equal to the number of wave tops per time unit.

The SI unit for frequency is Hertz (Hz) = wave tops pr second.

Ok, so that does not sound simple…

This is what you need to know:
The longer the distance the sound wave travels, the more energy is lost to absorption.

The ability of a sound wave to penetrate through tissue depends on the frequency of the sound wave – a lower frequency (lower number of wave tops) gives a better penetration.

On the other hand, a higher frequency (more wave tops) causes a higher resolution, but a lower penetration.

The presets relevant for basic emergency ultrasound are:

Physics
In physics, the word “ultrasound” refers to sound with a frequency the human ear cannot perceive.

Application
Ultrasound is used among other things as a sonic depth finder in navigation, for cleansing of sensitive objects (e.g. contact lenses) and in testing non-disruptive materials in order to detect faults and fractures.

In medical diagnostics, ultrasound can be used for visualisation of anatomical structures and for assessment of physiological processes.

The ultrasound used for medical diagnostics is usually between 2 and 18 MHz.

The first look at an ultrasound machine can be an intimidating experience.

You see a bunch of unfamiliar buttons and knobs and confusion sets in. The user manual is often poorly designed, which only adds to the confusion. You turn it on, stare at a screen, and feel lost.

But, it can be made simple and easy, and you can quickly master the machinery through a basic understanding of ultrasound and by using a few controls.

Learn the few essential buttons – On/Off, select transducer, select preset, adjust gain and depth – and you are up and running.