Physics Review (Edelman/Penny wrong/s)

Attenuation is determined by which of the following factors? A. Density and stiffness of the medium B. Freq. of sound and propagation speed C. PRF of sound and path length D. Path length and freq. of sound

Path length and freq. of sound

No effects of Cavitation have been observed for an in situ mechanical index value of less then: A. 0.8 B.2 C. 100 D.0.4

0.4

No effects of Cavitation have been observed for an in situ peak rarefaction pressures below aprox: A. 0.8 MPa B. 0.4 Rayls C. 100 Pa D.0.4 MPa

0.4 MPa

The speed of a 5 MHz continuous wave is 1.8 km/sec. The wave is then pulsed with a duty factor of 0.5. Calculate the new propagation speed

1.8 km/s this is the same for CW and PW, because propagation speed depends on the medium of the wave NOT whether it is continuous or pulsed

What is the typical voltage of the signal that is the input to the receiver of an ultrasound system? A. 0.1 volts B. 500 volts C. 250 volts D. 10 uvolts

10 uvolts. The signal sent back to the receiver is extremely small and is in the micro- to millivolts

No effects have been observed for a focused beam having a thermal index value of less then: A. 0.8 B.2 C. 100 D.0.4

2

Which value is closest to the impedance of the soft tissue? A. 1.5 kg Rayls B. 2.5 deci Rayls C. 19 mega Rayls D. 2,000,000 Rayls

2,000,000 Rayles (impedance of soft tissue is in the range of 1.5 to 2,500,000 Rayls

What is the typical range of Doppler shift found in diagnostic imaging examinations?

20 to 20 kHz

What is a typical pulser output voltage that excites the piezoelectric Crystal? A. 0.1 volts B. 500 mvolts C. 40 volts D. 10 microvolts

40 volts. The typical signal made by the pulser to excite the tx crystal may be in the range of tens of volts

In clinical imaging, what is the percentage of intensity that is transmitted when the sound beam strikes a boundary between two soft tissues?

99% or more between two very similar impedances

If the angle of incidence is 40• , 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. <40• B. >40• C. 40• D. Cannot tell the angle of transmission

>40•

True or False. Attenuation and propagation speed are unrelated?

True, attenuation is the weakening of a beam as it travels, has nothing to do with how fast it travels

The incidence between the sound wave and the boundary between Media 2 and 3 is normal. Impedance is different. What happens at the boundary between?

both reflection and transmission occur. there are normal incidence and different impedances

Which of these four pulses with PRF's listed below has the shortest PRP? a. 12kHz b. 6,000 Hz c. 20 kHz d. 1 kHz

c. 20 kHz

How does a cathode ray tube steer the charge particles emitted by the electron so that they sweep across the front screen? A. Phasing B. Mechanical steering C. Using a magnetic feild D. Reflecting off of a mirror

c. Using a magnetic feild

What is the duty factor if the pulse duration is 1µs and the pulse repetition period is 1ms? a. 100% b. 0.1 c. 0.01 d. 0.001

d. 0.001 The duty factor is 0.001, or 10^-3. 10^-6 divided by 10^-3 = 10^-3, or 0.001

No biological effects have been observed for and unfocused beam having free-feild SPTA intensities below: A. 100 mW/cm2 B. 10 W/cm C. 1000 mW/cm2 D. 1540 m/s

A. 100 mW/cm2

If all other factors remain unchanged, what happens to the duty factor [increases, decreases, remains the same] when imaging depth increases?

decreases

Acoustic Impedance is ____ x ____.

density x prop. speed

The difference in the front matching layer and the backing layer create?

destructive interference and significantly reduces reverberation artifact

What is the duty factor of the pulse duration is 1 millisecond, and the pulse repetition period is 1 second?

duty factor is 0.001 or 0.1%, 0.001 divided by 1.0 = 0.001

Acoustic velocity and Compressibility (Inversely, Directly, Unrelated)

inversely

Elasticity and Speed of Sound (Inversely, Directly, Unrelated)

inversely

[Related how?] Acoustic velocity and density. (Inversely, Directly, Unrelated)

inversely

Impedance is associated with _____

only the medium

If the initial intensity of a sound beam is less than the final intensity, then the gain in dB is ___ (+ or -).

positive

____ is the time from the start of a pulse to the end of that pulse.

pulse duration

____ is the time from the start of a pulse to the start of the next pulse.

pulse repetition period

Impedance is important in _____ at boundaries

reflections

Sound travels through a large quantity of muscle tissue. The reflector will be displayed. A. Too close to the reflector B. Too far from the reflector C. In the correct location D. Sound does not travel through muscle tissue

A. Too close to the transducer (muscle = ?mm/sec)0

Which of the following best describes the components of the damping material? A.epoxy resin loaded with tungsten B.tungsten resin loaded with lead zirconate titanate C.lead zirconate titanate impregnated with tungsten D. Tungsten impregnated with lead

A.epoxy resin loaded with tungsten

No effects have been observed for a focused beam having intensities below value of less then: A. 2 mW/cm B. 1 W/cm2 C. 100 mW/cm2 D. 4 mW/cm2

B. 1 W/cm2

The typical range of frequency for diagnostic ultrasound imaging is: A. 20 to 20,000 Hz B. 1 to 20 MHz C. 10 to 20 MHz D. 12 to 100 MHz

B. 1 to 20 MHz

What is the total amount of attenuation that occurs if a 6.0-MHz sound beam travels through 4 cm of soft tissue? A. 24 dB B. 12 dB C. 6 dB D. None of the above

B. 12 dB

A stenosis of 75% in the area is equal to what percent of stenosis in diameter? A. 25% B. 50% C. 75% D. 100%

B. 50%

Which of the following is not an accrediting agency of sonography labs? A. American Institute of Ultrasound in Medicine B. American Registry of Diagnostic Medical Sonography C. Intersocietal Commission for the Accreditation of vascular laboratories D. American College of Radiology

B. American Registry of Diagnostic Medical Sonography

As imaging depth increases, pulse repetition Period : A. Remains constant B. Increases C. Decreases D. Double

B. Increases

What happens as the frequency of the transducer increases? A. Penetration ability is increased B. The amount of scatter is increased C. The frequency shift is decreased D. The amount of attenuation is decreased

B. The amount of scatter is increased

Which of the following is not a true statement? A. Lateral resolution varies with depth B. A larger aperture results in a shorter near zone length C. A larger aperture produces less divergence in the far field D. Lateral resolution may also be referred to as azimuthal resolution

B. a larger aperture results in a shorter NZL

Refraction is affected by ____ in the media

the speed of sound

A sound wave travels 26us to a reflector. How far away is the reflector, assuming the medium is soft tissue? A. 0.5cm B. 1.0cm C. 2.0cm D. 4.0cm

C. 2.0 cm (4.0 cm would be total distance from reflector back to tx to make an image)

Which of the following frequency shifts would exhibit aliasing if the PRF is 5000 Hz? A. 1.0 kHz B. 2.5kHz C. 3.0 kHz D. none of the above

C. 3.0 kHz

The AIUM test object can evaluate all of the following except: A. Vertical distance B. Horizontal distance C. Contrast resolution D. Axial resolution

C. Contrast resolution

Which of the following is not a way in which venous blood is assisted in returning to the heart? A. Calf pump B. Inspiration C. Expiration D. Venous valves

C. Expiration

The part of the machine responsible for timing the reception of the pulses to determine their location is the: A. Beam former B. scan converter C. Master synchronizer D. Display

C. Master synchronizer

Which of the following is a methodical way of evaluating equipment performance on a routine basis to ensure proper and accurate equipment function? A. Accreditation B. Quality assurance C. Preventative maintenance D. Credentialing

C. Preventative maintenance

[True of False] PRF and PRP are determined only by the imaging depth

true

Which of the following test phantoms should be stored in an airtight container and in a controlled temperature? A. AIUM test object B. Doppler testing phantom C. Tissue-equivalent phantom D. String phantom

C. Tissue-equivalent phantom

The end diastolic component is missing on a spectra way form. Which of the following should be adjusted to fix this? A. Gain B. Scale C. Wall filter D. Frequency

C. Wall filter

A sound pulse travels in Medium 1 and strikes an interface with another tissue, Medium 2, at 30•. The angle of transmission is 10•. In which medium is the impedance higher? A. Medium 1 B. Medium 2 C. Can't be determined

C. refraction of sound at a boundary is unrelated to the impedances of the media.

Which of the following is not a credential granting body for sonographer's A. American Registry of Diagnostic Medical Sonography B. Cardiovascular credential international C. American Registry of Radiographic Technologists D. American Institute of Ultrasound in Medicine

D. American Institute of Ultrasound in Medicine

The only certifying agency that offers credentialing exams for cardiac and vascular testing is: A. ACR B. AIUM C. ICAVL D. CCI

D. CCI

Which of the following will not eliminate aliasing? A. increasing the PRF B. Increasing the Nyquist limit above frequency shift C. Decreasing the sample depth D. Increasing the frequency shift above the Nyquist limit

D. Increasing the frequency shift above the Nyquist limit

All of the following are goals for a quality assurance program except: A. Document proper equipt. Performance B. Optimize image quality consistently C. Keep detailed results from quality assurance testing D. Report equipt. malfunctions annually

D. Report equipt. malfunctions annually

What must be known in order to calculate distance to a reflector? A. Attenuation, speed, density B. Attenuation, impedance C. Density, speed D. Travel time, speed

D. Travel time, speed (Recall Range equation) D = speed x travel time D=C*t

Which two attributes help establish their acoustic impedance of a medium? A. Density and temperature B. Density and stiffness C. Stiffness and elasticity D. Elasticity and compressibility

Density and stiffness (Stiffness is directly related to propagation speed. Since z= density x propagation speed. B is the only logical answer from given

[T or F] The power of a wave is halved, The intensity is reduced to one fourth it's original value.

False. Intensity is the power of the beam divided by its cross-sectional area. If we halve the power then will halve the intensity

[❗️FIX] What is the relationship between alter sound frequency and the attenuation coefficient and soft tissue?

Him soft tissue, the attenuation go fishing in decibels per centimeter is approximately one half of the ultrasonic frequency and megahertz

If pulse repetition frequency increases, then the duty factor: A. Remains constant B. Increases C. Decreases D. Doubles

Increases

Which of the following is true of the diameter of the sound beam in the fresnel zone? A. It increases B. It decreases C. It does not change D. It is unpredictable

It decreases ❌it increases

In clinical imaging, what is the percentage of intensity that is reflected when the sound beam strikes a boundary between two soft tissues?

Less than or 1% (it is very little that gets reflected with two similar impedances like soft tissue to soft tissue interfaces

Which of the following is an appropriate unit of measurement for propagation speed? A. Millimeters per microsecond (mm/us) B. Watts per centimeter squared (W/cm2) C. Microseconds (us) D. Kilohertz (kHz)

Millimeters per microsecond (mm/us)