111 Formulas

Question 1

Frequency (MHz)

Answer 1

Prop Speed (mm/us) / Wavelength (mm)

Question 2

Frequency (MHz) *Inverse

Answer 2

1 / Period (us)

Question 3

Period (us)

Answer 3

1 / Frequency (MHz)

Question 4

Wavelength (mm)

Answer 4

Prop Speed (mm/us) / Frequency (MHz)

Question 5

PRF (kHz)

Answer 5

1 / PRP (ms)

Question 6

PRP (ms)

Answer 6

1 / PRF (kHz)

Question 7

PD (us)

Answer 7

Period (us) x #cycles in the pulse

Question 8

SPL (mm)

Answer 8

wavelength (mm) x #cycles in the pulse

Question 9

Duty Factor (unitless)

Answer 9

PD (us) / PRP (us)

Question 10

Quality Factor (unitless)

Answer 10

Op Freq / Bandwidth

Question 11

Prop Speed (mm/us)

Answer 11

Wavelength (mm) x Freq (MHz)

Question 12

Intensity (W/cm2)

Answer 12

Power (Watts) / Area (cm2)

Question 13

Intensity direct proportion to

Answer 13

Power & Amp2

Question 14

Amplitude units

Answer 14

Dependent on acoustic variable (Pa, g/cm3, cm, dB, etc)

Question 15

Attenuation Coefficient (dB/cm)

Answer 15

0.5 dB/cm x Freq (MHz)

Question 16

Frac Bandwidth

Answer 16

Bandwidth / Op Freq

Question 17

Positive Decibels

Answer 17

Signal strengthens (3dB=1/2; 6dB=1/4; 9dB=1/8; 12dB=1/16)

Question 18

Negative Decibels

Answer 18

Signal lessens (3dB=1/2; 6dB=1/4; 9dB=1/8; 12dB=1/16)

Question 19

Impedance (rayls)

Answer 19

density (kg/m3) x Prop Speed (m/s)

Question 20

IRC (unitless)

Answer 20

(Z1 - Z2)^2 / (Z1+Z2)^2

Question 21

IRC

Answer 21

Reflected Intensity (mW/cm2) / Incident Intensity (mW/cm2)

Question 22

ITC

Answer 22

1 - IRC

Question 23

ITC

Answer 23

Transmitted Intensity (W/cm2) / Incident Intensity (W/cm2)

Question 24

Range Equation (mm)

Answer 24

1/2 x [prop speed (mm/us) x pulse round trip time (us)]

Question 25

Op Freq (MHz)

Answer 25

Prop Speed (mm/us) / 2 x Thickness of element (mm)

Question 26

Lateral Resolution (mm)

Answer 26

Beam Width (or diameter) (mm)

Question 27

Axial Resolution (mm)

Answer 27

SPL (mm) / 2

Question 28

PRF (Hz)

Answer 28

foci x LinesPerFrame x FrameRate

Question 29

Pen Depth formula

Answer 29

Pen Depth (cm) x PRF (Hz)

Question 30

Typical DFs

Answer 30

Sonography- 0.1-1.0%

Doppler- 0.5-5.0%

Question 31

Typical DFs

Answer 31

Sonography- 0.1-1.0%

Doppler- 0.5-5.0%

Question 32

Useful freq for diagnostic

Answer 32

2 to 15 MHz

Question 33

Freq for optham deem and intravasc

Answer 33

Up to 50

Question 34

Transducer elem impedance compared to soft tissue

Answer 34

20 times more