CH. 1 Q's

The attenuation coefficient in soft tissue is equal to: A. 1/2 the operating frequency B. Double the operating frequency C. Frequency x Path Length D. Total decibels

A. 1/2 the operating frequency

An increase in PRF would lead to: A. An increase in DF B. A decrease in PD C. An increase in the number of cycles D. A decrease in resolution

A. An increase in DF

Areas of high pressure and density are referred to as: A. Compressions B. Rarefrations C. Diffractions D. Refractions

A. Compression

Which of the following is an appropriate unit of measurement for propagation speed? A. mm/us B. W/cm^2 C. ms D. kHz

A. mm/us

The typical range of frequency for diagnostic ultrasound imaging is: A. 20 to 20,000 Hz B. 1 to 20 MHz C. 2 to 15 kHz D. 12 to 100 MHz

B. 1 to 20 MHz

The major component of attenuation is: A. Scatter B. Absorption C. Transmission D. Refraction

B. Absorption

The portion of the sound beam where the molecules are farther apart describes an area of: A. Compression B. Rarefaction C. Refraction D. Amplitude

B. Rarefraction

The change in the direction of the original sound wave that occurs when sound interacts with two different tissue types that have a different propagation speed is referred to as: A. Wavelength B. Scattering C. Refraction D. Absorption

C. Refraction

In clinical imaging, the wavelength typically measures between: A. 1 and 10 Hz B. 1540 and 2000 m/s C. 0 and 1 D. 0.1 and 0.8 mm

D. 0.1 and 0.8 mm

Which of the following is considered the speed of sound in soft tissue? A. 1.54 m/s B. 0.77 m/s C. 100 mW/cm^2 D. 1540 m/s

D. 1540 m/s

The maximum value or minimum value of an acoustic variable minus the equilibrium value of the variable describes the: A. Power B. Intensity C. DF D. Amplitude

D. Amplitude

What is the change in power if the amplitude triples? A. It doubles B. It triples C. It quadruples D. It increases nine times

D. It increases nine times Power is proportional to amplitude

Which of the following would have the lowest propagation speed? A. Water B. Soft Tissue C. Bone D. Lung Tissue

D. Lung Tissue

All of the following are true of power except: A. As amplitude increases, power remains the same B. Power is proportional to amplitude squared C. Intensity is proportional to power D. Power is measured in milliwatts

A. As amplitude increases, power remains the same

As sound wave travels through the human body, the intensity of the sound wave decreases as a result of: A. Attenuation B. Elevational Resolution C. Huygen's Principle D. Refraction

A. Attenuation

Which of the following is determined by the sound source only? A. Frequency B. Wavelength C. SPL D. Propagation Speed

A. Frequency

Density and propagation speed are: A. Inversely related B. Directly related C. Directly proportional D. Unrelated

A. Inversely related

Density is typically measured in: A. Kilograms per centimeter cubed B. Millimeters C. Watts per square centimeter D. Pascals

A. Kilograms per centimeter cubed

Micro denotes: A. Millionth B. Hundredth C. Million D. Billionth

A. Millionth

What time is defined as the beginning of one pulse to the beginning of the next pulse and, therefore, includes both the "on" and "off" time? A. PRP B. PD C. DF D. PRF

A. PRP

Damping of the sound beam: A. Reduces the SPL B. Increases the SPL C. Increases the PD D. Has no impact on SPL or PD

A. Reduces the SPL

Which of the following is described as the ability of an object to resist compression and relates to the hardness of a medium? A. Stiffness B. Density C. Pressure D. Inertia

A. Stiffness

The DF for CW ultrasound is: A. 1.0% B. 100% C. 20,000 Hz D. 8 Pa

B. 100%

What is the total amount of attenuation that occurs if a 6MHz sound beam travels through 4 cm of soft tissue? A. 24 dB B. 12 dB C. 6 dB D. 1.5 dB

B. 12 dB

If the angle of incidence is 40 degrees, what is the angle of transmission at the interface if medium 1 has a propagation speed of 1320 m/s and medium 2 has a propagation speed of 1700 m/s? A. 0 degrees B. > 40 degrees C. < 40 degrees D. Cannot tell the angle of transmission

B. > 40 degrees Medium 2 > Medium 1

Which of the following would have the highest propagation speed? A. Air B. Bone C. Soft tissue D. Water

B. Bone

The prefix "Centi" denotes: A. Thousandths B. Hundredths C. Millions D. Hundreds

B. Hundredths

As imaging depth increases, PRP: A. Remains constant B. Increases C. Decreases D. Doubles

B. Increases

What is the change in intensity if the power decreases by half? A. Intensity doubles B. Intensity is halved C. Intensity is one-fourth D. Intensity does not change

B. Intensity is halved Power and intensity are directly related

All of the following are true of wavelength except: A. It is determined by both the medium and sound source B. It is equal to the period divided by frequency C. It is inversely related to frequency D. It is directly related to period

B. It is equal to the period divided by frequency

Pressure is typically expressed in: A. Frequency B. Pascals C. Decibels D. Kilograms per centimeter cubed

B. Pascals

If only the density of a medium is increased, then the: A. Propagation speed will increase B. Propagation speed will decrease C. Propagation speed will stay the same D. None of the above

B. Propagation speed will decrease

Which of the following requires an oblique interface and a propagation speed mismatch? A. Reflection B. Refraction C. Normal incidence D. Damping

B. Refraction

All of the following relate to the strength of the sound wave except: A. Amplitude B. Wavelength C. Intensity D. Power

B. Wavelength

What are the units for pressure? A. feet, inches, centimeters, or miles B. pascals or pounds per square inch C. kilograms per centimeter cubed D. hertz, kilohertz, or megahertz

B. pascals or pounds per square inch

SPL can be calculated by: A. # of cycles x frequency B. Period/Frequency C. # of cycles x wavelength D. # of cycles/wavelength

C. # of cycles x wavelength

Which of the following would be considered ultrasonic? A. 10 Hz B. 18 kHz C. 0.5 MHz D. 200 Hz

C. 0.5 MHz

Adding damping to the transducer improves which type of resolution? A. Transverse Resolution B. Temporal Resolution C. Axial Resolution D. Elevational Resolution

C. Axial Resolution

The percentage of time that the ultrasound system is producing pulses of ultrasound describes the: A. PRP B. PD C. DF D. PRF

C. DF

As imaging depth increase, the PRF must: A. Not change B. Increase C. Decrease D. PRF does not relate to imaging depth

C. Decrease

The inertia of the medium describes its: A. Attenuation characteristics B. Stiffness C. Density D. Elasticity

C. Density

What term is defined as "the power of a wave divided by the area over which the power is distributed?" A. Amplitude B. Power C. Intensity D. Absorption

C. Intensity

Transducers have material within them that, when electronically stimulated, produces ultrasound waves. This is most likely some form of: A. Tungsten Acetate B. Dilithium Zirconium C. Lead Zirconate Titanate D. Barium Sulfate

C. Lead Zirconate Titanate

Which of the following is defined as the number of ultrasound pulses emitted in 1 second? A. PRP B. DF C. PRF D. SPL

C. PRF

Sound is technically a: A. Transverse and longitudinal wave B. Mechanical and transverse wave C. Nonmechanical and pressure wave D. Mechanical and longitudinal wave

D. Mechanical and longitudinal wave

Which of the following is defined as only the active time? A. DF B. PRF C. Period D. PD

D. PD

Which of the following describes the amount of refraction that occurs at an interface? A. Bernoulli's Law B. Poiseuille's Law C. Law of reflection D. Snell's Law

D. Snell's Law

What are the units of DF? A. dB B. dB/cm C. Hz D. Unitless

D. Unitless

Which of the following is described as the distance over which one cycle occurs? A. PD B. DF C. Period D. Wavelength

D. Wavelength

Which of the following is determined by the sound source and medium? A. Speed B. Frequency C. Period D. Wavelength

D. Wavelength