Ultrasound Physics Registry Review

These flashcards cover key terminology and concepts from the Ultrasound Physics Registry Review lecture notes.

Properties of Sound

Sound is a mechanical, longitudinal wave that travels through a medium via molecule vibrations, consisting of pressure compressions and rarefactions.

Frequency

The number of cycles per second, measured in Hertz (Hz), indicating how often a wave occurs within a time period.

Wavelength

The length of one complete cycle of a sound wave, depending on both frequency and propagation speed.

Propagation Speed

The speed at which sound travels through a given medium, affected by the medium's stiffness and density.

Intensity

The power per unit area of a sound wave, measured in Watts/cm², indicating energy flow.

Decibels (dB)

A logarithmic unit used to express the ratio of powers, often used to describe intensity changes in ultrasound.

Impedance

A property of a medium indicating its resistance to sound passage, calculated from the product of density and propagation speed.

Attenuation

The reduction in strength of a sound wave as it travels through a medium, often resulting from absorption and reflection.

Doppler Effect

The change in frequency or wavelength of sound waves in relation to an observer moving relative to the source of the sound.

Pulse Repetition Frequency (PRF)

The number of pulses generated by the ultrasound machine per second, which varies with depth to avoid range ambiguity.

Quality Assurance (QA)

Periodic testing of ultrasound equipment to ensure optimal performance and image quality.

ALARA Principle

An acronym for 'As Low As Reasonably Achievable', emphasizing the importance of minimizing patient exposure to ultrasound energy.

Mechanical Index (MI)

A measure indicating the likelihood of cavitation in tissues, reflecting the potential for bioeffects at a given frequency and output.

Time Gain Compensation (TGC)

An adjustable control that compensates for signal attenuation with depth, maintaining uniform brightness across the ultrasound image.