Imaging - Ultrasound Flashcards
What will a sever angle of the ultrasound beam cause?
- Refraction and poor reflection.
- Can also increase artefacts.
Why should you hold the probe evenly across the skin surface?
- To allow an even take up of contrast media so the image produce is of a good quality throughout.
- if it’s uneven on one side then that side will be a lower quality image.
What is a high frequency ultrasound?
- Smaller and more direct.
- Give lots of information.
- Stay tight together and quite straight.
- Can’t go very deep in terms of getting an image, only shallow but produces a highly detailed image.
When might you use a high frequency ultrasound?
- Cardiac imaging (valves, input & output).
What is a low frequency ultrasound?
- Less quality/resolution images but allows imaging of deeper structures.
- Also able to see a wider field of view to see where we are.
When might you use a low frequency ultrasound?
- Abdomen scan, GI scan & internal organs.
The ultrasound probe head (transducer) is made up of 4 different materials, what are they?
- Metal or plastic outer casing.
- Piezoelectric crystals.
- Plastic ‘nose’ (touches patient).
- Acoustic insulator.
what does an acoustic insulator do?
- Concentrates/ promotes sound-waves to move forward into patient so they’re as helpful as can be.
Why should you never use surgical spirit as a contact media?
- Corrodes the nose piece and kills it over time.
What is an artefact?
- Something that gets in the way of structures and can mislead you to interpret different things.
What are the 3 C’s of patient prep for ultrasound?
- Clip
- Clean
- Contact Gel
Why should you ensure the patient is clipped and clean before an ultrasound?
- Because dirt and hair could cause artefacts on the image.
- Also if the patient is dirty, you might need to push the probe in harder to produce an image which will cause pain and discomfort to the patient.
Why should you try and soak the contact medium gel for 5 minutes if you can?
- Because the uptake will be better and therefore better quality images will be produced.
How will the images show if the patient is dirty or hairy?
- Speckly.
You can use a stand off for things like tendons and superficial structures, what is this and what does it do?
- It’s a gel pad that allows more distance between probe head and structure.
