Artifacts - Introduction - 2
Introduction
What is it? Ultrasound image(s) generated from echoes that does(do) NOT have an anatomic correlate -- whether it be size, shape, location...
It is NOT real. At most, partially real.
We encounter it everyday like what you seen on this window. What do you see on it?
Not only do you see what you expect such as the lights, lamps, and candles in the building, but you can, also, see a car, a bus, trees, sky and some other structures. The latter group of images do not originate from behind the glass yet you see them because light is reflected from the object (ie. car) to the window then into your field of vision.
It is NOT real. At most, partially real.
We encounter it everyday like what you seen on this window. What do you see on it?
Not only do you see what you expect such as the lights, lamps, and candles in the building, but you can, also, see a car, a bus, trees, sky and some other structures. The latter group of images do not originate from behind the glass yet you see them because light is reflected from the object (ie. car) to the window then into your field of vision.
US Artifacts are not esoterics for experts only. It is an integral part of the PoCUS competency continuum. It starts with image acquisition: choosing the correct probe, fine-tuning the knobs, and the ability to attain more than one view attenuates, if not mitigates, artifact production. Even if you acquired images, you need to be able to interpret whether what you are seeing is real or not; and some artifacts are clinical useful in the correct setting, and some are not. If it is not interpreted correctly, you may ignore the artifact yet, in fact, it is diagnostic; or you choose to use it, but incorrectly interpreted its meaning. All this can lead to faulty synthesis. Ultimately, this will impact clinical decision which can be potentially dangerous. So, it is worth introducing the concepts then revisiting them in the future after you have the learned the clinical correlate. You will find the images makes a lot more sense as you scan more and more.
Is there anyway to mitigate, or, at least, attenuate the artifacts?
These are 3 simple ways to deal with them:
These are 3 simple ways to deal with them:
- Recognition: You have to know what you are looking at is an artifact - or, at least, suspect it so that you may further test it
- Knobology: Certain artifacts can be mitigated/attenauted/accentuated depending on the settings
- >1 View: View the region of interest at >1 view - most artifacts will not persist when imaged from another angle (especially when you change the sonographic environment - distance, tissue traversed). This is an easier solution than playing around the knobology. Just remember the idiom, "One View is No View."
Take Home Messages:
- US Artifact has no anatomical correlate in the region being scanned
- It can either be an image interpretation confounder, or a diagnostic aid
- Know when you are looking one
- Be suspicious of "misplaced" echoes as being an artifact
- Always verify by imaging from >1 view