units & measurements

cm to mm

Move decimal right

mm to cm

Move decimal left

Area

Length × width

Volume

Length × width × height

Speed of sound in soft tissue

1,540 m/s or 1.54 mm/µs

1 cm depth reflector

13 µs

how to calculate total distance traveled

amount of cm x 2 (because it’s the distance going and coming back)

calculate time for depth reflector

cm x 13 (bc one cm is equal to 13)

Period

Time for one complete cycle

Frequency

Number of cycles of a periodic process that occurs per unit time

Time and frequency relationship

Inverse relationship

Velocity

Speed in a particular direction

Acceleration

Rate of change in velocity

20 Hz or below

Infrasound

audible

20-20000 hz

ultrasound

20000 Hz or above

Anechoic

Black with no echoes

Hypoechoic

Dark with low echoes

Isoechoic

Same or equal amount of echo

Hyperechoic

Bright with many echoes