Ultrasound Theory Flashcards
What type of image is produced
B- mode image
What is AI
Acoustic impedance is the measure of resistance that ultrasonic waves encounter as they pass through time
Where does changes in acoustic impedance occur
At interfaces
A higher Difference in acoustic impedance causes
Stronger echoes
What transducers are better for superficial structures (eg muscoskeletal)
Higher frequency transducers
What transducers are better for deep structures e.g. abdomen
Lower frequency transducers
What do Doppler examine
Movement mainly bloodflow
What angle to hold the Doppler at
45 to 60° angle to axial beam
What does the colour red mean in Doppler examinations
Blood flow Towards transducer
What does the colour blue mean in Doppler examinations
Blood flow away from transducer
What is required for acoustic coupling
Gel
Curved away transducers emit
Lower ultrasonic waves which means you can see deeper structures
Phased away transducers are used to see
The heart
On the short axis blood vessels appear as a
Circle
On the long axis blood vessels appear as a
Tube
