US Flashcards
What generated the US?
Piezoelectric crystal and ceramic material
oscillate and produce periodic vibration
US propagation in human soft tissue =
1540 m/s
Refraction=
Whaen the US beam travels btw. two different medium with an oblique incidence
What can we get when using about 200 US transducer at the same time in the same location?
Increased temparture MRI Guided Focused US
Convex probe features
3.5-5.5 MHz
Good penetration
Lower resolution
Linear probe features
8-5
Poor penetration
Higher resolution
Which other US probes do you know?
TEE
Phase array (cardio)
Laparoscopic
Pencil
What is the simplest mode of US?
A mode
When do we use M mode?
Cardiology mostly
M mode=
shows the reflecting echoes position’s change over time along a single US beam
Motion as function of time
Which mode of US is used usually?
B mode
In Doppler, when the source of the sound is approaching-
The pitch is Lower/Higher
The wavelength is Longer/Shorter
The pitch is Higher
The wavelength is Shorter
Different Doppler modes (4)
Color
Contineous (CW)
Pulse (PW)
Power
Flow towards the trancducer will be what color?
Red
Blue on Doppler indicated
Flow is away from the trancducer
What is contineous Doppler good for?
It can make very high velocity measurable
What is Power Doppler used for?
To display flow without directional information
How can we measure soft tissue elasticity and stiffness?
Sonoelastography
Stiffer structure will be in what color?
Blue
Softer structure will be in what color?
Red
2 types of elastography
- Static, with compression- Strain elastography
2. Dynamic, newer- Shear wave elastography
Where should we look for free abdominal fluid on US exam?
Perihepatic space Hepatorenal recess Splenorenal recess Rectovesical recess (Male) Douglas pouch (Female) Ileocoecal region
Hepatorenal recess is laso called
Morisons’s pouch
