Ultrasound Technology Quiz

Sound waves with frequencies above the range of human hearing.

A medical imaging technique that uses high-frequency sound waves to create images of soft tissues.

The process of transmitting signals or waves through a substance or medium to a specific point.

A device that generates sound pulses, detects echoes, and directs the pulse through the patient.

Ultrasound uses non-ionizing longitudinal sound waves, unlike CT and nuclear medicine which use ionizing radiation.

Ultrasound records signals from reflected sound waves, while X-rays rely on transmission through tissues.

The speed of sound waves varies depending on the medium (solid, liquid, or gas) it travels through.

Ultrasound creates detailed gray-scale tomographic images that represent tissue structure.

Electromagnetic waves, like light, do not require a medium to travel and can move through a vacuum. They are made up of energy packets called photons.

Sound waves, also known as phonons, are mechanical waves that need a medium (solid, liquid, or gas) to travel. They cannot travel through a vacuum.

Ultrasound imaging utilizes high-frequency sound waves to create images of internal structures in the body. It is safe and effective to view soft tissues, unlike X-rays which use radiation.

Piezoelectric materials transform mechanical pressure into electrical energy and vice versa. They play a crucial role in ultrasound transducers for both generating and detecting sound waves.

The Direct Piezoelectric Effect is when a piezoelectric material generates electricity when mechanical stress is applied. The Reverse Piezoelectric Effect is when an electric field causes the material to compress or stretch.

Zinc Oxide, Gallium Nitride, Quartz, Bone, and some proteins are examples of materials that exhibit the piezoelectric effect.

A device like a transducer converts one form of energy into another. In ultrasound, piezoelectric materials are used within the transducer for generating and detecting sound waves.

The number of wave cycles per second.

The distance between two consecutive points of the same phase on a wave.

The speed at which sound travels through a medium.

A property of a medium that describes its resistance to compression.

The relationship between frequency, wavelength, and the speed of sound.

How the speed of sound changes as it travels from one medium to another.

The change in wavelength of an ultrasound wave as it travels between mediums.

The change in speed of an ultrasound wave as it transitions between different materials.

The reflected ultrasound wave retains its original wavelength and stays in phase with the incoming wave.

The strength of reflection depends on the difference in acoustic impedance between two materials.

Ultrasound waves bounce off boundaries with large impedance differences, like between soft tissue and bone.

Ultrasound waves reflect weakly when encountering small impedance differences, like between different soft tissues.

Scattering occurs when an ultrasound beam encounters irregular surfaces or particles that are similar in size to the wavelength of the ultrasound.

Scattered echoes from the incident ultrasound beam form a cone around the reflection axis.

Scatter intensity decreases proportionally to the fourth power of frequency (f^4).

Speckle is the grainy, textured noise in ultrasound images caused by constructive interference of scattered ultrasound waves from different tissue sites.

Transmission is the part of the ultrasound beam that passes through tissue without being reflected back.

Refraction occurs when a transmitted ultrasound beam changes direction as it passes through different tissues with varying sound speeds.

Attenuation is a decrease in ultrasound intensity as it travels through tissue.

Absorption is the main cause of ultrasound attenuation, where tissue absorbs ultrasound energy.

The absorption coefficient describes how much ultrasound energy is absorbed by tissue, increasing with frequency.

The half-value thickness (HVT) is the distance in tissue where ultrasound intensity decreases by half (3 dB).

Higher frequency ultrasound has a higher attenuation coefficient and a smaller HVT, meaning it loses intensity faster.

Acoustic impedance (Z) describes how sound travels through a material. It's influenced by the material's density (how heavy it is) and the speed of sound within that material.

Each material has a unique and constant acoustic impedance. This means sound interacts differently depending on the material.

Acoustic impedance can be related to a material's stiffness and flexibility. Similar stiffness allows sound to pass through, while large differences cause reflection.

When sound encounters a boundary between two materials with very different acoustic impedances, more sound reflects back, and less passes through.

Acoustic impedance differences are essential for ultrasound imaging. By measuring how sound is reflected at tissue boundaries, details within the body can be visualized.

Specular reflection is a type of ultrasound reflection that happens when sound interacts with a smooth tissue boundary. It’s the key to creating clear ultrasound images.

When an ultrasound wave strikes a surface perpendicularly, a portion of the wave reflects back, providing valuable information for ultrasound imaging.

Specular reflection is essential for creating detailed ultrasound images because it provides strong, focused reflections that accurately reveal internal structures.