(2nd) quiz 1

To convert electrical energy

What is the primary function of a piezoelectric crystal in an ultrasound transducer?

Lead zirconate-titanate

Which material is commonly used in piezoelectric crystals due to its high sensitivity

To absorb ultrasound

What is the purpose of the damping material in an ultrasound transducer?

Phased array probe

Which ultrasound probe is best suited for cardiac imaging?

To eliminate air gaps

What is the primary advantage of using a coupling medium (gel) in ultrasound imaging?

B-mode

Which mode displays a two-dimensional grayscale image of anatomical structures?

Spatial pulse length

What determines axial resolution in ultrasound imaging?

Appears black

Which of the following is a characteristic of an anechoic structure?

To reduce acoustic impedance

What is the function of the matching layer in a transducer?

Endocavitary probe

Which probe is typically used for endovaginal examinations?

Transducer/probe

A device that converts electrical energy into ultrasound waves and receives echoes to create images.

Piezoelectric principle

the principle where mechanical pressure generates electrical charges in certain crystals.

Matching layer

The layer in a transducer that reduces acoustic impedance mismatch between the crystal and skin.

A mode

The mode that displays amplitude spikes representing echo depth and intensity.

Coupling medium/gel

a gel applied to the skin to eliminate air gaps during ultrasound

Lateral resolution

The resolution determined by beam width, affecting the ability to distinguish side-by side objects.

Acoustic shadowing

The phenomenon where sound waves pass through Auid without attenuation, causina brightness behind the structure.

Doppler mode

A Doppler technique that displays blood flow velocity as a spectral waveform, allowing precise measurements.

M mode

The mode used to track motion over time, such as fetal heartbeat.

Continuous-Wave Doppler

The Doppler mode used in echocardiography lo evaluate heart valve function.

False, low (high)

PZT crystals are used in transducers due to their low sensitivity.

False, increases (reduces)

The damping material increases the ringing of the piezoelectric crystal.

False, linear (curvilinear)

A linear probe is ideal for deep abdominal imaging.

True

B-mode displays real-time, two-dimensional grayscale images.

False, axial (lateral)

Axial resolution depends primarily on beam width.

False, air (gel)

Air is an excellent coupling medium for ultrasound.

False, darker (brighter)

A hyperechoic structure appears darker than surrounding tissue.

False, rectangular (fan-liked)

The phased array probe produces a rectangular image.

False, Doppler effect (frequency or wavelength)

The Doppler Effect describes the change in amplitude of sound waves when reflecting off moving objects

False, less (more)

Power Doppler is less sensitive to slow blood flow than color Doppler.