ultrasound 2-4

Piezoelectric effect

This is the ability of a material to generate an electrical charge in response to applied pressure

Piezin

Means to press, pressure, or squeeze

Quartz

Naturally occuring crystals

Lead zirconate titanate

Man made ceramics

Plumbium zirconate titanate

PZT stands for

Quartz, tourmaline, rochelle salt

3 natural crystals

Dipolar molecules

Piezoelectric materials are crystalline materials composed of _______

Electrical to mechanical

Piezoelectric materials are used in the PRODUCTION OF ULTRASOUND by converting?

Mechanical to electrical

Piezoelectric materials are used in the DETECTION OF ECHO by converting?

Acoustic impedance

The resistance offered by tissues to the movement of particles caused by the ultrasound waves

High

A substance which has densely packed molecules will have a _____ acoustic impedance

Low

A substance which has loosely packed packed particles will have a _____ acoustic impedance

1540 meters per second

The average velocity of ultrasonic waves in soft tissue is _____

Acoustic impedance mismatch

The difference in acoustic impedance between two substances is known as the ______

No reflection

Substances with the same acoustic impedance have a total transmission of energy and therefore ______

Ultrasound beam

The area through which the sound energy emitted from the ultrasound transducer travels is known as _____

symmetrical

The beam is three dimensional and is _______ around its central axis

Side lobes

The extraneous beams of the ultrasound generated from the edges of individual transducer

Beam width

Refers to the dimension of the beam in the scan plane