E4- Ultrasound Flashcards
When was ultrasound first used in medicine?
What was it popular in?
Why was it popular?
- 1950’s
- obstetrics
- no ionizing radiation.
- US is described as seeing using _____________.
- Examples in nature?
- Military?
- sound waves
- bats + dolphins
- submarines
Advantages of ultrasound.
- Identify anatomical structures
1. * Relationship of the needle to tissues
1. * Increases accuracy
1. * “See” spread of LA
1. * May decrease time performing pain blocks/assessments
1. * May decrease complications
Ultrasound waves travel between these Mhz.
- 2-20 Mhz
Travels differently w/ different structures
What is the range of audible sounds?
- 20-20,000 Hz
- What 3 can ultrasound waves do when they encounter a surface?
sound waves are ______ back to crystals + create impulse on computer
- Transmit through the surface
- Reflect on the surface
- Something in between
Reflected
What is the result when ultrasound waves are transmitted through fluid?
- No signal
- Anechoic
- Dark
What is the result when ultrasound waves are reflected on bones/stones?
- Lots of signals
- Hyperechoic
- Bright
What results when ultrasound waves encounter soft tissue, muscles, and fat?
- Iso/hypoechoic
- Shades of grade
Which picture represents a solid?
Which picture represents fluid?
- Picture A: Solid
- Picture B: Fluid
What is inside the transducer’s head that changes shape with an electric impulse?
- Piezo Electric Crystals
Starts to vibrate … generate sound wave
What are the three types of transducers used in POCUS?
- Linear Array
- Curve Array
- Phased Array
Describe a Linear Array
- High frequency (7-15 MHz)
- Better resolution
- superficial depth
- IV, CVL, art line
Describe a Curve Array
- Low frequency (2-5 MHz)
- Poorer resolution
- Great for deeper tissue
- kidney, liver, spleen, bladder, GI
Describe a Phased Array
- Lowest frequency (1-3 MHz)
- Useful for echocardiography
- axial plane?
- coronal plane?
- sagittal plane?
- top : bottom
- front : back
- Left : right
Static vs Dynamic Approach for Ultrasound
Static: Identifying the target vessel, assessing the patency, marking an appropriate insertion site, and cannulating blindly.
Dynamic: Performing the procedure in real-time and viewing the needle puncturing the vessel wall.
Tips and Tricks for using Ultrasound.
- Proper Ergonomics
- Use Conductive gel
- Hold probe like pencil
- Focus using gain + depth
What is gain?
- brightness signal quality
- adjusted with a knob.
- Twist the knob back + forth until… fluid = black + soft tissue = mid-grey
What is depth?
- 2 up/down buttons
- shown in cm on screen
- start at highest depther + get object in middle of screen
In-plane vs. Out-of-plane refers to the relationship of ______ to the ultrasound plane.
long/short axis refers to ___________ and should always be ______________ axis for procedures
- needle
- vessel ,, long
What is the advantage of in-plane ultrasound?
Disadvantage?
- Advantage: See the whole needle
- Disadvantage: Easy to be off plane
What is the advantage of out-of-plane ultrasound?
Disadvantage?
- Advantage: The needle is positioned directly under the plane of an ultrasound
- Disadvantage: Unclear where tip of the needle is
What do you look for to determine that your guidewire is in the vessel’s lumen?
- Vanishing Sign
