DAVIES ULTRASOUND PHYSICS
REVIEW EXAM QUESTIONS WITH 100%
CORRECT ANSWERS LATEST VERSION
2025/2026.
1. What action would be most in keeping w the ALARA principle while performing a diagnostic
ultrasound exam? - ANS Complete the diagnostic scan in a timely fashion at the lowest
output power that achieves a quality image
Advocating use of the ALARA principle (as low as reasonably achievable) prudently minimizes
the risk of bio effects (even tho epidemiological studies have revealed no known risk associated
with the use of diagnostic ultrasound).
2. During performance of an obstetric ultrasound exam, you adjust the system parameters to
improve the image. Which of the following parameters would increase acoustic exposure? -
ANS Increase transmit power.
The transmit power is the only control listed that will affect the exposure of the patient to
acoustic power. Gain, TGC, and frame averaging (persistence) do not affect sound transmission
and therefore do not affect exposure. Increasing frequency will not increase exposure.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,3. To minimize the risk of biologic effects of ultrasound to the fetus, which imaging mode
tradeoff would be most applicable? - ANS Use M-mode instead of pulsed-wave Doppler to
measure the fetal heart rate.
Pulsed wave Doppler increases the time average intensity compared to M-mode.
4. What potential bioeffect occurs through absorption of sound energy by tissue? -
ANS Heating
Sound attenuation in tissue is primarily due to absorption (conversion of ultrasound to heat).
5. When practicing universal precautions, you should do all the following EXCEPT: - ANS Wash
gloves between exams for reuse from one patient to another. (It is recommended that gloves be
worn during every ultrasound examination. They should be discarded after use).
-wear gloves when there is a potential for contract with patient body fluid
-change gloves when moving from one patient to another
-Wash hands immediately after gloves are removed
- Wear face masks or eye protection whenever there is a possibility of blood splashing in your
face
6. A nosocomial infection is defined as one that: - ANS Is hospital-acquired
7. Thermally induced biologic effects should be preventable by avoiding a local tissue
temperature increase exceeding: - ANS 1°C
8. Which intensity descriptor has the lowest numeric value for the characterization of a pulsed-
wave ultrasonic field? - ANS SATA
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,SATA, a term that is infrequently used, means spatial average, time average. Note: I(SPTA) is the
spatial peak, time average intensity; I(SPTP) is the spatial peak, temporal peak.
9* Increased tissue heating could occur when you: - ANS 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 an: - ANS Epidemiological study
Which of the following actions is NOT compliant w HIPPA? - ANS Reviewing your neighbors
medical studies on your hospital PACS system so you can give her your opinion of her condition
The Health Insurance Portability and Accountability Act (HIPPA) includes rules to protect the
privacy of the individuals health information. This answer would violate HIPPA
What does the mechanical index indicate on an ultrasound system? - ANS The likelihood of
cavitation during an ultrasound exam
Mechanical index is derived from the peak rarefaction pressure and the ultrasound freq,
parameters shown to be associated w onset of cavitation
In medicine, what do the initials PHI indicate? - ANS Protected health information
14*What should you limit when the thermal index exceeds 1? - ANS Exposure time
15*To practice the ALARA principle, which of the following techniques should you employ? -
ANS Use the lowest transmit power that allows adequate tissue visualization
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Use a high gain and low transmit power
The thermal index indicates: - ANS Estimated temperature increase in tissue
Temperature increase is calculated assuming certain values for the absorption and thermal
properties of tissues and taking into account factors such as beam geometry, freq and power.
Technically, it is the ratio of the power being produced to the power needed for a 1° C
temperature increase if tissues have the assumed properties
17*The operator control most directly adjusts the intensity of the transmitted pulse? -
ANS Acoustic output (transmit) power
Pulse repetition freq can also affect the intensity, specifically the I(SPTA) because it affects the
duty factor
Which of the following would show the highest intensity value? - ANS SPTP
Note that Im is the intensity over the half wave period within the transmit pulse where it is the
greatest! This term is seldom specified
Which intensity parameter is not applicable for continuous wave ultrasound? - ANS SPPA and
SAPA refer to pulse average intensities, which do not apply to continuous wave ultrasound.
Which of the following would most likely have the highest SPTA value? - ANS PW doppler
Using a hydrophone, you can measure: - ANS Pressure amplitude and duty factor
Which of the following parameters relates to tissue heating? - ANS Absorption
4 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
REVIEW EXAM QUESTIONS WITH 100%
CORRECT ANSWERS LATEST VERSION
2025/2026.
1. What action would be most in keeping w the ALARA principle while performing a diagnostic
ultrasound exam? - ANS Complete the diagnostic scan in a timely fashion at the lowest
output power that achieves a quality image
Advocating use of the ALARA principle (as low as reasonably achievable) prudently minimizes
the risk of bio effects (even tho epidemiological studies have revealed no known risk associated
with the use of diagnostic ultrasound).
2. During performance of an obstetric ultrasound exam, you adjust the system parameters to
improve the image. Which of the following parameters would increase acoustic exposure? -
ANS Increase transmit power.
The transmit power is the only control listed that will affect the exposure of the patient to
acoustic power. Gain, TGC, and frame averaging (persistence) do not affect sound transmission
and therefore do not affect exposure. Increasing frequency will not increase exposure.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,3. To minimize the risk of biologic effects of ultrasound to the fetus, which imaging mode
tradeoff would be most applicable? - ANS Use M-mode instead of pulsed-wave Doppler to
measure the fetal heart rate.
Pulsed wave Doppler increases the time average intensity compared to M-mode.
4. What potential bioeffect occurs through absorption of sound energy by tissue? -
ANS Heating
Sound attenuation in tissue is primarily due to absorption (conversion of ultrasound to heat).
5. When practicing universal precautions, you should do all the following EXCEPT: - ANS Wash
gloves between exams for reuse from one patient to another. (It is recommended that gloves be
worn during every ultrasound examination. They should be discarded after use).
-wear gloves when there is a potential for contract with patient body fluid
-change gloves when moving from one patient to another
-Wash hands immediately after gloves are removed
- Wear face masks or eye protection whenever there is a possibility of blood splashing in your
face
6. A nosocomial infection is defined as one that: - ANS Is hospital-acquired
7. Thermally induced biologic effects should be preventable by avoiding a local tissue
temperature increase exceeding: - ANS 1°C
8. Which intensity descriptor has the lowest numeric value for the characterization of a pulsed-
wave ultrasonic field? - ANS SATA
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,SATA, a term that is infrequently used, means spatial average, time average. Note: I(SPTA) is the
spatial peak, time average intensity; I(SPTP) is the spatial peak, temporal peak.
9* Increased tissue heating could occur when you: - ANS 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 an: - ANS Epidemiological study
Which of the following actions is NOT compliant w HIPPA? - ANS Reviewing your neighbors
medical studies on your hospital PACS system so you can give her your opinion of her condition
The Health Insurance Portability and Accountability Act (HIPPA) includes rules to protect the
privacy of the individuals health information. This answer would violate HIPPA
What does the mechanical index indicate on an ultrasound system? - ANS The likelihood of
cavitation during an ultrasound exam
Mechanical index is derived from the peak rarefaction pressure and the ultrasound freq,
parameters shown to be associated w onset of cavitation
In medicine, what do the initials PHI indicate? - ANS Protected health information
14*What should you limit when the thermal index exceeds 1? - ANS Exposure time
15*To practice the ALARA principle, which of the following techniques should you employ? -
ANS Use the lowest transmit power that allows adequate tissue visualization
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Use a high gain and low transmit power
The thermal index indicates: - ANS Estimated temperature increase in tissue
Temperature increase is calculated assuming certain values for the absorption and thermal
properties of tissues and taking into account factors such as beam geometry, freq and power.
Technically, it is the ratio of the power being produced to the power needed for a 1° C
temperature increase if tissues have the assumed properties
17*The operator control most directly adjusts the intensity of the transmitted pulse? -
ANS Acoustic output (transmit) power
Pulse repetition freq can also affect the intensity, specifically the I(SPTA) because it affects the
duty factor
Which of the following would show the highest intensity value? - ANS SPTP
Note that Im is the intensity over the half wave period within the transmit pulse where it is the
greatest! This term is seldom specified
Which intensity parameter is not applicable for continuous wave ultrasound? - ANS SPPA and
SAPA refer to pulse average intensities, which do not apply to continuous wave ultrasound.
Which of the following would most likely have the highest SPTA value? - ANS PW doppler
Using a hydrophone, you can measure: - ANS Pressure amplitude and duty factor
Which of the following parameters relates to tissue heating? - ANS Absorption
4 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
