Review for US physics

The period of a wave has to do with

Time

The arterial pressure of a standing patient is 120mmHg. What would be the BP at the ankle?

100mmHg

If the number of cycles in a pulse remains the same, but the frequency is increased, what will happen to the pulse duration?

It will decrease

Axial resolution is increased when we have:

High frequency

All of the following are associated with CW Doppler transducer except:

backing material

A duplex ultrasound system displays ______ information

Two-dimensional image and Doppler

A 4MHz sound wave with an intensity of 10.0 mW is attenuated by 3db. What is the final intensity?

5.0 mW

A PW transducer receives an 8MHz electrical stimulus. What frequency would be produced by the active element?

8 MHz

Which of the following formulas is used to calculate propagation speed of sound in a medium?

Speed = Frequency x Wavelength

A reflector that is longer than the wavelength of the sound beam is called a _____reflector?

specular

The resistance that a medium presents to the propagation of sound is called

Impedance

Lateral resolution is most closely related to

Transducer diameter

An ultrasound beam has an initial value of 1200mW/cm2. Its final intensity after travelling through tissue is 120 mW/cm2. The reduction can be expressed a

-10 dB

Which of the following is not associated with turbulent flow?

parabolic

eddy

vortex

swirling

A system is using 10MHz tissue harmonics while scanning. The transducer being used in the study is most likely to be a______

5 MHz curved array

What part of the ultrasound beam is found at 1NZL?

The Focal point

The highest Doppler frequency without the appearance of aliasing is called the _________ and is equal to ________.

Nyquist limit, half of the emitted PRF

The range of frequencies produced by a PW transducer is from 2 MHz to 10 MHz. What is the bandwidth?

8 MHz

True or False: Turbulent flow is considered silent flow.

False

In a pulsed -wave system, what determines the frequency of the sound generated by the probe?

PZT thickness

The effect of sound on soft tissue is referred to as

Bioeffects

True or False: Power Doppler is color flow that shows blood flow direction and velocity

False

When two sound waves meet and merge together to make a larger wave.

Constructive interference

The maximum or minimum change in the energy of a wave is called the _______

Amplitude

What process takes place when echoes return to the transducer?

the reverse piezoelectric effect

One strategy for removing the aliasing involves:

Decreasing the transducer frequency

When scanning, most of the sound energy in an ultrasound beam is attenuated as ____________ energy.

heat

A RUQ study is being done with a 4 Mhz transducer. The image is enhanced by activating the Harmonics feature of the machine. What is the fundamental frequency?

4 MHz

A curved array transducer has a matching layer that is 2mm in thickness. What would be the wavelength of the operating frequency?

4 mm

True or False: Wide bandwidth probes have a low Q- factor

True

When you change the DEPTH when scanning a patient, what part of the pulsed wave are you actually changing?

the off time

Phasic flow most commonly apperars in ________ circulation

venous

Which of the following frequencies is within the human audible range?

15 kHz (20Hz - 20,000Hz)

The technique that fires elements in an array in small groups at a time, is known as

sequential firing or phasing