2
Davies Ultrasound Physics Review questions with || || || || || ||
precise detailed answers || ||
1. What action would be most in keeping w the ALARA principle while performing a
|| || || || || || || || || || || || || || ||
diagnostic ultrasound exam? - ✔✔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? -
|| || || || || || || || || || || || || ||
✔✔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.
3. To minimize the risk of biologic effects of ultrasound to the fetus, which imaging mode
|| || || || || || || || || || || || || || || ||
tradeoff would be most applicable? - ✔✔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? -
|| || || || || || || || || || || || ||
✔✔Heating
,2
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: -
|| || || || || || || || || || || || ||
✔✔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: - ✔✔Is hospital-acquired
|| || || || || || || || || || ||
7. Thermally induced biologic effects should be preventable by avoiding a local tissue
|| || || || || || || || || || || || ||
temperature increase exceeding: - ✔✔1°C || || || ||
8. Which intensity descriptor has the lowest numeric value for the characterization of a
|| || || || || || || || || || || || || ||
pulsed-wave ultrasonic field? - ✔✔SATA || || || ||
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: - ✔✔Increase transmit power
|| || || || || || || || || || ||
,2
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: - ✔✔Epidemiological study
|| || || || || || || || || || ||
Which of the following actions is NOT compliant w HIPPA? - ✔✔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? - ✔✔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? - ✔✔Protected health information
|| || || || || || || || || || ||
14*What should you limit when the thermal index exceeds 1? - ✔✔Exposure time
|| || || || || || || || || || || ||
15*To practice the ALARA principle, which of the following techniques should you employ?
|| || || || || || || || || || || ||
- ✔✔Use the lowest transmit power that allows adequate tissue visualization
|| || || || || || || || || || ||
Use a high gain and low transmit power
|| || || || || || ||
The thermal index indicates: - ✔✔Estimated temperature increase in tissue
|| || || || || || || || ||
, 2
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? -
|| || || || || || || || || || || || ||
✔✔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? - ✔✔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? - ✔✔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? - ✔✔PW doppler
|| || || || || || || || || || || || || ||
Using a hydrophone, you can measure: - ✔✔Pressure amplitude and duty factor
|| || || || || || || || || || ||
Which of the following parameters relates to tissue heating? - ✔✔Absorption
|| || || || || || || || || ||
23* Which of the following occurs when you use the maximum system gain?
|| || || || || || || || || || || ||
Davies Ultrasound Physics Review questions with || || || || || ||
precise detailed answers || ||
1. What action would be most in keeping w the ALARA principle while performing a
|| || || || || || || || || || || || || || ||
diagnostic ultrasound exam? - ✔✔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? -
|| || || || || || || || || || || || || ||
✔✔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.
3. To minimize the risk of biologic effects of ultrasound to the fetus, which imaging mode
|| || || || || || || || || || || || || || || ||
tradeoff would be most applicable? - ✔✔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? -
|| || || || || || || || || || || || ||
✔✔Heating
,2
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: -
|| || || || || || || || || || || || ||
✔✔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: - ✔✔Is hospital-acquired
|| || || || || || || || || || ||
7. Thermally induced biologic effects should be preventable by avoiding a local tissue
|| || || || || || || || || || || || ||
temperature increase exceeding: - ✔✔1°C || || || ||
8. Which intensity descriptor has the lowest numeric value for the characterization of a
|| || || || || || || || || || || || || ||
pulsed-wave ultrasonic field? - ✔✔SATA || || || ||
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: - ✔✔Increase transmit power
|| || || || || || || || || || ||
,2
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: - ✔✔Epidemiological study
|| || || || || || || || || || ||
Which of the following actions is NOT compliant w HIPPA? - ✔✔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? - ✔✔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? - ✔✔Protected health information
|| || || || || || || || || || ||
14*What should you limit when the thermal index exceeds 1? - ✔✔Exposure time
|| || || || || || || || || || || ||
15*To practice the ALARA principle, which of the following techniques should you employ?
|| || || || || || || || || || || ||
- ✔✔Use the lowest transmit power that allows adequate tissue visualization
|| || || || || || || || || || ||
Use a high gain and low transmit power
|| || || || || || ||
The thermal index indicates: - ✔✔Estimated temperature increase in tissue
|| || || || || || || || ||
, 2
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? -
|| || || || || || || || || || || || ||
✔✔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? - ✔✔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? - ✔✔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? - ✔✔PW doppler
|| || || || || || || || || || || || || ||
Using a hydrophone, you can measure: - ✔✔Pressure amplitude and duty factor
|| || || || || || || || || || ||
Which of the following parameters relates to tissue heating? - ✔✔Absorption
|| || || || || || || || || ||
23* Which of the following occurs when you use the maximum system gain?
|| || || || || || || || || || || ||
