ULTRASONOGRAPHY LECTURE II

Key Wave Properties

Important characteristics of waves that influence sonography.

Ultrasound

Sound waves with frequencies above the human hearing range, used in medical imaging.

Physics of Ultrasound

The study of the physical principles governing ultrasound behavior and propagation.

Acoustics

A branch of physics that deals with sound and sound waves.

Experiential Definition of Sound

What we hear through the human auditory system.

Physical Definition of Sound

Propagation of pressure variations through a medium from a sound source to a listener.

Mechanical Wave

A form of energy causing mechanical disturbance through vibration of molecules in a medium.

Longitudinal Wave

A type of mechanical wave where molecules move in the same direction as the wave.

Medium

A substance through which sound travels, requiring molecules for transmission.

Acoustic Variables

Characteristics of sound that include pressure, density, and particle motion.

Ultrasound Wave

A sound wave that travels in a sinusoidal form.

Longitudinal Wave

A type of ultrasound wave characterized by compression and rarefaction.

Transverse Wave

A type of ultrasound wave where particle motion is perpendicular to wave direction.

Compression

Regions of high pressure in a sound wave.

Rarefaction

Regions of low pressure in a sound wave.

Frequency

The number of cycles per second in a sound wave, measured in Hertz (Hz).

Ultrasound Imaging Frequency Range

The frequency range for ultrasound imaging, typically 2-20 MHz.

Period (T)

The time it takes for a sound wave to complete one cycle, measured in seconds or microseconds.

Wavelength

The distance over which one cycle of a wave occurs.

Propagation Velocity

The speed at which a sound wave travels through a medium, influenced by density and stiffness.

Amplitude

The strength or intensity of a sound wave, affecting image brightness in ultrasound.

Power

The rate at which energy is transmitted into the body, measured in watts (W).

Intensity

The amount of energy per second passing through a specified area, measured in decibels (dB).

Pressure

The amount of force applied over a specific area, measured in Pascals (Pa).