Final- Ultrasound (7/24/23) Flashcards
When was ultrasound first used in medicine?
What was it popular in?
Why was it popular?
- 1950’s
- Popular first in obstetrics
- It was popular because there was no ionizing radiation.
Advantages of ultrasound.
- Identify anatomical structures
- Relationship of the needle to tissues
- Increases accuracy
- “See” spread of LA
- May decrease time performing pain blocks/assessments
- May decrease complications
Ultrasound waves travel between these Mhz.
- 2-20 Mhz
What is the range of audible sounds?
- 20-20,000 Hz
What can ultrasound waves do when they encounter a surface?
- Transmit through the surface
- Reflect on the surface
- Something in between
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?
- 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
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 at a superficial depth
- Great to use to start a central line with to look for an IJ
Describe a Curve Array
- Low frequency (2-5 MHz)
- Poorer resolution
- Great for deeper tissue
- Used to look at gallbladder or stomach to assess NPO
Describe a Phased Array
- Lowest frequency (1-3 MHz)
- Useful for echocardiography
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.