How does ultrasound work?

What is ultrasound?

Ultraound is a common imaging modality that allows visualisation in real-time. As such it is becoming increasingly popular on the wards for diagnosis and management purposes. You should be familiar with its operation and know in which situations it may help your clinical decision making.

What is ultrasound used for?

Ultrasound can be used for

Assessment of jugular venous pressure (JVP)

Venepuncture

Focused assessment for screening in trauma (FAST)

Lumbar puncture

Thoracentesis

Paracentesis

Evaluation of abdominal organs

Biopsy

Pregnancy

How does ultrasound work?

1. High-frequency sound waves are transmitted from a transducer.

2. These sound waves are then reflected by different tissue types in different ways.

3. The reflected sound waves are then picked up by the ultrasound transducer.

4. The sound waves are then transformed into an image by special software.

The first steps of performing an ultrasound involve:

Turning on the machine (easy, but often overlooked; often a button in the upper left or right corner of the keypad).

Entering the patient’s information (e.g. name, date of birth, hospital number).

Selecting an appropriate ultrasound probe for the area being examined.