US - Understanding US Physics - 7 Flashcards
def GO-RETURN TIME
aka time-of-flight
=elapsed time from pulse creation»_space; pulse reception
GO-RETURN TIME r/t depth
direct
avg speed - soft tissue
1.54 mm/micro.s
GO-RETURN TIME equation r/t depth
DEPTH (mm) = [1.54mm/micro.s x GO-RETURN TIME(micro.s)]
/ {2}
13 microsecond rule
w/ soft tissue, every 13 micro.s = 1 cm reflector depth
travel distance r/t reflector distance
travel distance = 2x reflector distance
draw - travel distance, reflector distance
note ch 7
def PULSE REPETITION PERIOD (PRP)
PRP = time from start–start of a pulse
PULSE REPETITION PERIOD (PRP) r/t max depth
direct
PULSE REPETITION PERIOD (PRP) r/t shallow depth
down PRP
shallow DEPTH
PULSE REPETITION PERIOD (PRP) r/t deep depth
up PRP
deep DEPTH
draw PULSE REPETITION PERIOD (PRP) r/t shallow & deep depth
note ch 7
PULSE REPETITION PERIOD (PRP) equation r/t soft tissue
PRP (micro.s) = IMAGING DEPTH (cm) x 13micro.s/cm
soft tissue - speed of sound
154,000 cm/s
PULSE REPETITION FREQUENCY (PRF) r/t max depth
inverse