ultrasound

Question 1

ultrasound uses what frequency waves for imaging?

Answer 1

high; 20,000 Hz to ~100 MHz (100,000,000 Hz) ultrasounds; right above audible sound
-in the machine, frequencies range from 2 - ~18 MHz

Question 2

t/f: ultrasound very invasive

Answer 2

false; non-invasive, safe, used in medical diagnostics

Question 3

how does ultrasound react at boundary of two mediums (soft-tissue vs air)?

Answer 3

much of transmitted wave bounces back (reflection) due to mismatch of density; cannot easily transfer its energy across the impedance boundary

Question 4

which structures allow sound waves to pass through?

Answer 4

soft tissues & fluid-filled organs allow most waves to pass through

Question 5

which structures doesn’t allow sounds waves to pass through?

Answer 5

denser structures like bones (sound waves reflected back to transducer)

Question 6

what do the echoes of the waves tell us?

Answer 6

the time it takes for echoes to return to transducer & strength (amplitude) tells us distance & characteristics of tissues encountered

Question 7

what can the visualization of the ultrasound show?

Answer 7

size, structure, any pathological lesions within organs and tissues

Question 8

can ultrasound be used to see retroflex tongue differences?

Answer 8

no because can’t see tongue tip cuz of the gap (air) between bottom of mouth to the tongue tip