Formula quiz

Period (us)

Period x Frequency = 1

What is the relationship between period and frequency

Period and frequency are inversely related, also known as reciprocals.

Power (watts)

power = amplitude²

How are power and amplitude related?

Power is proportional to amplitude² (directly related)

Intensity (W/cm²)

Intensity (W/cm²) = power (W) / area (cm²)

How are intensity and power related?

Intensity and power are directly related / proportional.

How are Intensity and amplitude related?

Intensity and proportional to amplitude²

What is the rule that defines the relationship between frequency and wavelength of sound in soft tissue (general wavelength formula)

Wavelength (mm) = 1.54 mm/us / frequency (MHz)

How are wavelength and frequency related?

Wavelength and frequency are inversely related

Wavelength formula example with frequency of 2

1.54 mm / 2 = 0.77 mm

Propagation Speed

speed (m/s) = frequency (Hz) x wavelength (m)

How are speed, frequency and wavelength related?

All directly related

Pulse duration (us)

pulse duration (us) = # cycles x period (us)

How are pulse duration and # of cycles related?

Directly related

How are pulse duration and period related

Pulse duration and period are directly related

Other pulse duration formula

pulse duration (us) = # cycles / frequency (MHz)

How are pulse duration and frequency related?

PD and frequency are inversely related

Spatial pulse length (mm)

spatial pulse length (mm) = # cycles x wavelength (mm)

How are spatial pulse length and # of cycles related?

SPL and # of cycles are directly related

How are spatial pulse length and wavelength related?

SPL and wavelength are directly related

How are spatial pulse length and frequency related

SPL and frequency are inversely related

Pulse repetition period (us)

1/PRF or PRF x PRP = 1

Pulse repetition frequency (Hz)

PRF = 1/PRP or PRF x PRP = 1

How are PRP and PRF related?

PRP and PRF are inversely related (reciprocals)

Duty factor (%)

duty factor (%) = pulse duration / pulse repetition period x 100

How are duty factor and pulse duration related?

They are directly related

How are duty factor and PRP related?

DF and PRP are inversely related

Rayleigh scattering

rayleigh scattering ∞ to frequency^4

Relationship between rayleigh scattering and frequency

Rayleigh scattering is proportional to frequency^4 (directly related)

Attenuation (dB)

total attenuation (dB) = Attenuation Coefficient (dB/cm) x distance (cm)

attenuation coefficient

attenuation coefficient (dB/cm) = frequency (MHz) / 2

How is the attenuation coefficient and frequency related?

attenuation coefficient and frequency are directly related

Other attenuation coefficient formula

attenuation coefficient = 0.5 dB/cm/MHz

Impedance (rayls)

Impedance (rayls) = density (kg/m³) x propagation speed (m/s)

Imaging depth (the depth of the reflector can be accurately calculated from the go-return time using the following equation)

depth (mm) = 1.54 mm/us x go-return time (us) / 2

PRP (imaging depth) mathematically in soft tissue:

PRP (us) = imaging depth (cm) x 13 us/cm

PRF (imaging depth) mathematically in soft tissue:

PRF (Hz) = 77,000 cm/s / imaging depth (cm)

Quality factor

Quality factor = main frequency / bandwidth

Frequency (ch.8)

frequency (MHz) = sound’s speed in PZT (mm/us) / 2 x thickness (mm)

Focal depth

Focal depth (mm) = diameter (mm)² x frequency (MHz) / 6

Other focal depth formula

focal depth (mm) = diameter (mm)² / 4 x wavelength (mm)

Axial resolution

axial resolution (mm) = spatial pulse length (mm) / 2

Axial resolution

axial resolution (mm) = wavelength (mm) x # of cycles in pulse / 2

Axial resolution in soft tissue formula:

axial resolution (mm) = 0.77 x # of cycles in pulse / frequency (MHz)

Lateral resolution

Lateral resolution (mm) = beam diameter (mm)

Beam divergence

Sin divergence angle = 1.85 / diameter (mm) x frequency (MHz)

Other beam divergence formula

sin divergence angle = 1.2 x wavelength / diameter