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Davies SPI REVIEW Questions and
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What action below would be most in keeping with the ALARA principle while performing a diagnostic ultrasound examination?
A: Allow multiple students to scan an obstetrical patient because the fetus is in a good position for imaging.
B: Prolong the sonogram to make videos of the fetus for each family member.
C: Complete the diagnostic scan in a timely fashion at the lowest output power that achieves a quality image.
D: Maximize the acoustic output to brighten the overall image.
E: Extend the sonogram beyond the intended scope of the exam requisition. ✔✔C: Complete the
diagnostic scan in a timely fashion at the lowest output power that achieves a quality image.
What does the ALARA principle stand for? ✔✔As Low As Reasonable Achievable
During performance of an obstetrical ultrasound exam you adjust the system parameters to improve the image. Which of the following parameters would increase acoustic exposure?
A: Increase gain
B: Increase TGC
C: Increase frequency
D: Increase transmit power
E: Increase frame averaging ✔✔D: Increase transmit power
While performing a sonogram to minimize risk to the fetus which imaging mode trade off would be most applicable?
A: Use M-mode instead of pulsed-wave Doppler to measure the fetal heart rate.
B: Use color Doppler instead of power Doppler to image the umbilical cord.
C: Use pulsed-wave Doppler instead of power Doppler to evaluate the fetal heart.
D: Use harmonics instead of fundamental to image the fetal spine.
E: All of the above. ✔✔A: Use M-mode instead of pulsed-wave Doppler to measure the fetal
heart rate.
Gain, TGC, and frame averaging do not affect _______ and therefore do not affect _______.
✔✔-Sound transmission
T or F: Increasing frequency does not increase exposure. ✔✔True
C: Hospital-acquired
D: Not contagious
E: Requires isolation ✔✔C: Hospital-acquired
Thermally induced biological effects should be preventable by avoiding a local tissue temperature increase exceeding:
A: 1 degree C
B: 4 degrees C
C: 10 degrees C
D: 95 degrees F
E: None; thermal effects have no threshold. ✔✔A: 1 degree C
Which intensity descriptor has the lowest numerical value for the characterization of a pulsed- wave ultrasonic field?
A: SATA
B: SPTA
C: SATP
D: SPTP
E: These intensity descriptors are only used for continuous-wave ultrasound. ✔✔A: SATA
Increased tissue heating could occur when you:
A: Decrease frequency.
B: Increase transmit power.
C: Decrease exposure time.
D: Decrease pulse repetition frequency.
E: All of the above ✔✔B: Increase transmit power.
A study designed to determine if there is an association between an adverse effect in a population and exposure to a particular agent is a(n):
A: Case report
B: Epidemiological study
C: In vitro study
D: In vivo study
E: Single-incident investigation ✔✔B: Epidemiological study
Which of the following actions is NOT compliant with HIPAA?
A: Private health indicator
B: Personal heart index
C: Personal health information
D: Private health institute
E: Protected health information ✔✔E: Protected health information
What should you limit when the thermal index exceeds 1?
A: Overall gain
B: TGC
C: Exposure time
D: Scanning depth
E: All of the above ✔✔C: Exposure time
To practice the ALARA principle which of the following techniques should you employ?
A: Always use the least amount of Reciever gain that allows adequate tissue visualization.
B: Adjust the controls so that the MI and TI read outs exceed 1.
C: Use the lowest transmit power that allows adequate tissue visualization.
D: Use the highest frame averaging setting.
E: Maximize exposure time. ✔✔C: Use the lowest transmit power that allows adequate tissue
visualization.
The thermal index indicates:
A: Estimated maximum temperature increase in tissue
B: Minutes of exposure time before heating is too great
C: Seconds of exposure time before heating is too great
D: Acoustic power in milliwatts
E: Liklihood of cavitation ✔✔A: Estimated maximum temperature increase in tissue.
Which operator control most directly adjusts the intensity of the transmitted pulse?
A: Receiver gain
B: Depth of scanning
C: Acoustic output (transmit) power
D: Time gain compensation (TGC)
E: Pulse repetition frequency ✔✔C: Acoustic output (transmit) power
Which of the following would show the highest intensity value?
E: Fetal monitor Doppler ✔✔D: PW Doppler
Using a hydrophone you can measure?
A: Impedance
B: Pressure amplitude
C: Duty factor
D: All of the above
E: B and C only ✔✔E: B and C only
Which of the following parameters relates to tissue heating?
A: Absorption
B: Impedance
C: Refraction
D: Propagation speed
E: All of the above ✔✔A: Absorption
Which of the following occurs when you use the maximum system gain?
A: Increased tissue heating
B: Increased risk of cavitation
C: Fluid particle streaming
D: Increased sound absorption
E: None of the above ✔✔E: None of the above
You are performing a sonogram and notice that the thermal index (TI) is greater than 1. Any increase in temperature would be greatest in:
A: Liver
B: Lung
C: Kidney
D: Bone
E: Bladder ✔✔D: Bone
The motion of particles in a fluid is sometimes observed in an intense ultrasound beam. This is termed:
A: Acoustic streaming
B: Transient cavitation
C: Thermal interaction
D: Rarefaction
The following advantage is associated with use of the MI and TI indices:
A: The system will automatically adjust parameters to limit exposure under adverse conditions.
B: The system will beep to notify the sonographer when indices are too great.
C: The system will shut down when exposure becomes too great.
D: The sonographer can easily dial in a safe exposure limit for each patient.
E: Information is available on the screen to help the sonographer implement the ALARA
principle. ✔✔E: Information is available on the screen to help the sonographer implement the
ALARA principle.
When scanning with pulsed-wave Doppler you would affect the acoustic exposure by changing which of the following?
A: Doppler gain
B: High pass filter
C: Pulse repetition frequency
D: Baseline position
E: Doppler angle ✔✔C: Pulse repetition frequency
What should you do to avoid nosocomial and cross-infection with sonographic probes?
A: Probe cleaning should always precede high-level disinfection.
B: Covering a probe with a condom is a sufficient barrier to infection for intracavitary probes.
C: Disinfection using a germicide compatible with the transducer is indicated when the probe is in contact with mucous membranes.
D: Alcohol soak of each probe should occur between patients.
E: A and C ✔✔E: A and C
The mass you are imaging has a diameter of 35mm. This value can also be expressed as:
A: 350 cm
B: 0.35 cm
C: 3.5 cm
D: 35 m
E: 3.5 m ✔✔C: 3.5 cm
Relative measurement of intensity based on a logarithmic scale is expressed in:
A: Newtons per cm squared
B: Watts per cm squared
C: Decibels
D: Pascals
E: Number of electrical impulses applied to the transducer per second. ✔✔C: Number of cycles
per second.
While performing a Doppler ultrasound examination you adjust the pulse repetition frequency to 12 kHz. This can also be expressed as:
A: 0.12 Hz
B: 1200 Hz
C: 1.2 MHz
D: 12,000 Hz
E: 120 MHz ✔✔D: 12,000 Hz
In sound wave propagation a region of elevated pressure is termed:
A: Compression
B: Demodulation
C: Rarefaction
D: Period
E: Resonance ✔✔A: Compression
When you switch from a 2.5 MHz to a 5 MHz transducer the sound wavelength:
A: Doubles
B: Quadruples
C: Halves
D: Quarters
E: Is unaffected ✔✔C: Halves
Sound propagates through tissue as a series of _______ and ______. ✔✔-Compressions
-Rarefactions
Wavelength is ______ to frequency. Doubling the frequency ______ the wavelength. ✔✔-
Inversely proportional
-Halves
Wavelength depends on what two factors?
A: Frequency and amplitude.
B: Amplitude and propagation speed.
C: Period and frequency.
Which of the following factors does NOT affect impedance?
A: Stiffness
B: Density
C: Propagation speed
D: Frequency
E: All of the above affect impedance. ✔✔D: Frequency
What is the propagation speed of fat? ✔✔1,460 m/s
What is the propagation speed of liver? ✔✔1,555 m/s
What is the propagation speed of blood? ✔✔1,560 m/s
What is the propagation speed of muscle? ✔✔1,600 m/s
What is the propagation speed of bone? ✔✔4,080 m/s
Impedance increases if _______ is increased or ______ is increased and is also affected by
______ and is not affected by _______. ✔✔-Density
-Propagation speed
-Stiffness
-Frequency
You are imaging a structure containing two media having the same acoustic impedance. What will occur at the boundary of the two structures?
A: All of the sound will be transmitted.
B: All of the sound will be reflected.
C: Some of the sound will be refracted.
D: Some of the sound will be reflected and some of the sound will be transmitted.
E: Most of the sound will be absorbed at the media boundary. ✔✔A: All of the sound will be
transmitted.
Indicates a 90 degree angle of incidence. ✔✔Normal incidence
What is the purpose of the gel coupling between the transducer and the skin?
A: To reduce heating of the epidermis caused by sound absorption and friction.
