RAD-US Flashcards
(44 cards)
What are advantages of an US?
-portable -easy -can do immediately at the bedside -interpret real-time (POCUS) -no radiation -can scan almost anything -low cost -can be taught to anyone!
What are the disadvantages of other imaging modalities (MRI/Ct/X-ray)?
-usually have to move patient -radiation -time consuming -need radiologist to help interpret many -expensive -obesity can be a barrier -may have to give contrast
What are the disadvantages of an US?
-less detailed -can miss things -operator error
What are the advantages of other imaging modalities?
-higher level of detail -less dependent on human error -choice for brain/neuro pathology
How do US work?
Ultrasound probe sends and receives sound waves - the object will transmit waves depending on its density that will bounce back and show a picture based on the sound waves
What does hyperechoic mean?
-tissue reflects -ULS waves appear bright
What things will appear hyperechoic?
-bones -stones -muscle (not super bright) -liver/kidney
What does hypoechoic mean?
-tissue absorbs ULS waves and not a lot is getting reflected back -will appear dark
What things appear hypoechoic?
-blood -fluid
What does isoechoic mean?
same echogenicity as surrounding structures
What does anechoic mean?
-No intermal echos -dark w/ no activity
What is shadowing?
-an object is so reflected that below that there is less activity casting a shadow -this is very common with stones
Does air reflect or absorb US waves?
Neither! It’s the enemy on US
Turning the gain up does what?
It makes the picture brighter so, turning it down makes it darker
What are the kinds of probes we use?
- linear 2. phased array (aka: cardiac) 3. curvilinear 4. endocavitary
Describe the linear probe and what we use it for.
-high frequency = can see better detail but over very small area -used for: skin/soft tissue, blood vessels, most procedures and eye -beams do not go very deep
Describe the phased array probe and what we use it for.
-small face but fans out into larger region -great for getting in between ribs into intercostal spaces (bone causes lots of artifact and can impair image) -best for echo -called the cardiac probe
Describe the curvilinear probe and what we use it for.
-low frequency - poor detail -large, wide face helps with scanning large areas -great for abdominal exam
Describe the endocavitary probe and what we use it for.
-intraoral - looking for peritonsillar abscess -vaginal ultrasound to look at ovaries/uterus
What if a FAST exam?
-focused assessment with sonography in trauma -looking for “free fluid” (blood) in RUQ, LUQ, suprapubic region, orvpericardium -can be expanded to look for hemothorax/pneumothorax as well
What probe do we use for a FAST exam?
-curvilinear probe b/c of the large surface area -doesn’t give a lot of detail, but we can easily identify free fluid/blood
What are the goals of a FAST exam?
-rapidly identify source of hypotension in trauma patient: free-fluid in the abdomen including hemorrhage -check 3 places where blood loss can happen (abdomen, pericardium, and lung) -in hypotensive patient, don’t need to wait for ct > go directly to OR -can decide to put in chest tube immediately -WAY less invasive than DPL (diagnostic peritoneal lavage)
What is a DPL?
-diagnositc peritoneal lavage -put fluid into the abdomen and draw it back out to see if blood comes back -we don’t want to do this if we can avoid it, because we’re violating the peritoneum
What are views of the bedside echo?
-parasternal long axis -parasternal short axis -subxiphoid -apical 4 chamber **not the same as a detailed cardiology echo
