Davies Ultrasound Physics Review Questions with Answers
(100% Correct Answers)
Where is the point of maximum intensity in a sound beam?
A: Curie point
B: Fresnel zone
C: Focal point
D: Fraunhofer zone
E: F number —Answer: C: Focal point
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. —Answer: C.
Complete the diagnostic scan in a timely fashion at the lowest output power that achieves a
quality image.
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?
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,A: Increase gain
B: Increase TGC
C: Increase frequency
D: Increase transmit power
E: Increase frame averaging —Answer: D: Increase transmit power
To minimize the risk of biological effects of ultrasound to the fetus, which imaging mode
tradeoff 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. —Answer: A. Use M-mode instead of pulsed-wave Doppler to measure the
fetal heart rate.
What potential bioeffect occurs through absorption of sound energy by tissue?
A. Cavitation
B. Heating
C. Attenuation
D. Reflection
E. Refraction —Answer: B. Heating
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,When practicing universal precautions you should do all of the following EXCEPT:
A: Wear gloves when there is a potential for contact with patient bodily fluids.
B: Change gloves when moving from one patient to another.
C: Wash hands immediately after gloves are removed.
D: Wear face masks or eye protection whenever there is a possibility of blood splashing into
your face.
E: Wash gloves between exams for re-use from one patient to another. —Answer: E: Wash
gloves between exams for re-use from one patient to another.
A nosocomial infection is defined as one that:
A. Is resistant to antibiotics
B. Is restricted to the respiratory system
C. Is hospital-acquired
D. Is not contagious
E. Requires patient isolation —Answer: C. Is 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
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, E: None; thermal effects have no threshold. —Answer: 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. —Answer: 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 —Answer: 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
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(100% Correct Answers)
Where is the point of maximum intensity in a sound beam?
A: Curie point
B: Fresnel zone
C: Focal point
D: Fraunhofer zone
E: F number —Answer: C: Focal point
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. —Answer: C.
Complete the diagnostic scan in a timely fashion at the lowest output power that achieves a
quality image.
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?
© 2025 All rights reserved
,A: Increase gain
B: Increase TGC
C: Increase frequency
D: Increase transmit power
E: Increase frame averaging —Answer: D: Increase transmit power
To minimize the risk of biological effects of ultrasound to the fetus, which imaging mode
tradeoff 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. —Answer: A. Use M-mode instead of pulsed-wave Doppler to measure the
fetal heart rate.
What potential bioeffect occurs through absorption of sound energy by tissue?
A. Cavitation
B. Heating
C. Attenuation
D. Reflection
E. Refraction —Answer: B. Heating
© 2025 All rights reserved
,When practicing universal precautions you should do all of the following EXCEPT:
A: Wear gloves when there is a potential for contact with patient bodily fluids.
B: Change gloves when moving from one patient to another.
C: Wash hands immediately after gloves are removed.
D: Wear face masks or eye protection whenever there is a possibility of blood splashing into
your face.
E: Wash gloves between exams for re-use from one patient to another. —Answer: E: Wash
gloves between exams for re-use from one patient to another.
A nosocomial infection is defined as one that:
A. Is resistant to antibiotics
B. Is restricted to the respiratory system
C. Is hospital-acquired
D. Is not contagious
E. Requires patient isolation —Answer: C. Is 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
© 2025 All rights reserved
, E: None; thermal effects have no threshold. —Answer: 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. —Answer: 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 —Answer: 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
© 2025 All rights reserved
