Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
104 Cards in this Set
- Front
- Back
- 3rd side (hint)
Heating depends most directly on |
SPTA |
|
|
The time average intensity refers to intensity average of |
Pulse repetition period |
|
|
The following signals represent intensities from a pulse echo scanner. which valve is the highest? |
I(SPPA) |
|
|
Which intensity has the lowest value |
I TA (on and off) |
|
|
The term I m defines the |
Maximum intensity and has units of watts per centimeter squared |
|
|
The SPTP intensity of a typical post acoustic wave |
Exceeds The SATA intensity, exceeds the SPTE intensity, exceeds the SATP intensity (all of them) |
|
|
If an unfocused transducer produces 10 MW of power and the transducer has an area of 2 cm² the SATA at the transducer surface is |
5 mW/cm^2 |
|
|
The AIUM statement on bioEffects claims that there have been no KNOWN effects from exposure to tissue at spatial peak temporal average intensities below for a focused sound beam |
1000 mW/cm^2 (1W/cm^2) |
|
|
The AIUM statement on bio affects claims that there have been no known affects from exposure to tissue at spatial peak temporal average intensities below for an unfocused sound beam |
100 mW/cm^2 |
|
|
Another term for beam uniformity ratio is |
SP/SA factor |
|
|
All of the following are unitless except |
Frequency |
|
|
The (SA) spatial average for the ultrasound beam is 30. The SP (spatial peak) intensity is 60. The BUR ratio is (SP/SA) |
60/30 |
|
|
A sound beam with equal intensities across the beam will have a beam uniformity ratio that is equal to |
One |
|
|
Ultrasound transducer A has a uniformity factor of five. Transducer B has a beam uniformity ratio of one. Which transducer has the brighter center |
Transducer A |
If BUR is greater than one the center of the beam has higher BUR values |
|
Two acoustic beams have identical SPTP intensities of 400 MW/cm². One beam is pulse while the other is continuous wave. Which beam has the highest SPTA intensity |
The continuous wave |
|
|
What are the acceptable units for the beam uniformity coefficient |
None of the above |
It’s always unitless |
|
What is another name for the beam uniformity coefficient |
SP/SA factor |
|
|
Acoustical power is given in |
Watts |
|
|
Units for acoustical intensity are |
Megawatts per centimeter squared |
|
|
Which of the following devices are used for measuring acoustical pressures and determining acoustical intensities |
Hydrophone |
|
|
Intensity is related to the |
Square of the pressure amplitude |
|
|
The following signals represent intensities from a pulse echo scanner. Which value is the highest |
I(SPPA) |
|
|
The ultrasound mode producing the highest spatial peak time average intensity is |
Pulse Doppler |
|
|
Which intensity has the lowest value |
TA(includes on and off) |
|
|
The AIUM statement on bioEffects claims that there have been no known effects from exposure to tissue at spatial peak – temporal intensity below _______ in and unfocused beach |
100 mW/cm^2 |
|
|
Heating depends most directly on |
SPTA |
|
|
The time average intensity refers to intensity average of |
Pulse repetition period (on & off) |
|
|
If an unfocused transducer produces a power of 20 MW of power, and the transducer has an area of 2 cm², the I(SATA) transducer surface is |
10 mW/cm^2 |
P/A 20/2=10 |
|
The AIUM statement on bioeffects claims that there have been no known effects from exposure to tissue at spatial peak – temporal intensity is below _______ in and focused beam |
1000 mW/cm^2 |
|
|
All of the following are accepted for ultrasound bioeffects except |
Transducer type |
|
|
______________ cabbie ocean is the expansion and contraction of gas bubbles with potential micro streaming |
Stable |
|
|
The AIUM has stated that there has been no confirmed reports of adverse affects to living mammals if the temperature rise is less than |
2°C |
|
|
All of the following are ways to test for ultrasound effects for ultrasound bioeffects except |
Biology |
|
|
Mechanisms by which ultrasound energy could induce a biological effect include |
Heating |
|
|
At present the best indication that there have been no ill-effects on the human fetus exposed to ultrasound comes from |
Epidemiological studies |
|
|
Exposure of cells in a fluid is an example of |
In vitro study |
|
|
To minimize exposures to ultrasound, sonographers should scan using |
Low transmit power, high receiver gain |
|
|
___________________ is the science of identifying and measuring the characteristics of an ultrasound beam that are relevant to its potential for producing biological effects |
Dosimetry |
|
|
Protocol is established in specific information is obtained |
Prospective study |
|
|
When testing ultrasound equipment for cyst detection the best method is |
Tissue equivalent test object |
|
|
What standard is best used in a quality assurance program |
Objective |
|
|
What form of resolution is evaluated by measuring the width of reflections arising from small point targets |
Lateral resolution |
|
|
What form of resolution is evaluated by visualizing closely spaced pins that are parallel to the beams main access |
Axial resolution |
|
|
At what intervals should quality assurance evaluations be performed |
Routinely |
|
|
What potential bioeffect occurs through absorption of sound energy by tissue |
Heating |
|
|
Thermally induced biologic affects should be preventable by avoiding a local tissue temperature increase exceeding |
1°C |
|
|
Which intensity descriptor has the lowest numerical value for the characterization of a pulsed wave ultrasonic field |
SATA |
|
|
Increased tissue heating could occur when you |
Increase transmit power |
|
|
A study designed to determine if there is an association between an adverse effect in a population and exposure to a particularly agent is an |
Epidemiologic studies |
|
|
What does the mechanical index indicate on an ultrasound system |
Minutes of exposure time before tissue heating is too great |
|
|
What should you limit when the thermal index exceeds one |
Exposure time |
|
|
To practice the ALARA principle which of the following techniques should you employ |
Use the lowest transmit power that allows the adequate tissue visualization |
|
|
The thermal index indicates |
Minutes of exposure time before heating is too great |
|
|
Which operator control most likely adjust the intensity of the transmitted pulse |
Acoustic output (transmit) power |
|
|
Of the following would have the highest intensity value |
SPTP |
|
|
Which intensity parameter is not applicable for continuous wave ultrasound |
SPPA, SAPA |
|
|
Which of the following would most likely have the highest SPTA value |
PW Doppler |
|
|
Using a Hydro phone you can measure |
Pressure amplitude and duty factor |
|
|
Which of the following occurs when you use the maximum system gain |
None of the above |
|
|
Per for him being a sonographic examination and noticed that the thermal index is greater than one any increase in temperature would be greatest in |
Bone |
|
|
Which of the following parameters relates to tissue heating |
Absorption |
|
|
The motion of particles and fluid is sometimes observed in an intense ultrasound beam this is termed |
Acoustic streaming |
|
|
You are performing a sonographic examination and noticed that the TI reading is one. What does that indicate |
The patient’s temperature has increased 1°C as a result of ultrasound scan |
|
|
What sonographic application has the lowest FDA approved SPTA value |
Ophthalmic |
|
|
The following advantage is associated with use of the MI and TI indices |
Information is available on the screen to help the sonographer implement the ALARA principal |
|
|
When scanning with PW Doppler you would affect the acoustic exposure by changing which of the following |
Pulse repetition frequency |
|
|
During the performance of an obstetric ultrasound you must adjust your system parameters to improve the image. Which of the parameters would increase acoustic exposure |
Increase transmit power |
|
|
Which of the following statements are true of a tissue equivalent phantom |
It has the same propagation speed as that of soft tissue, it attenuates ultrasound at a rate similar to soft tissue, embedded in it are solid masses and cystic structures, it is the device of choice for quality studies |
|
|
Which of the following is different for a tissue equivalent phantom and an AIUM 100 test object |
Grayscale |
|
|
All of the following may be used to evaluate Doppler systems except |
Tissue equivalent phantom |
|
|
Which modes of Doppler may be assessed with the Doppler phantom |
Color flow Doppler, pulse wave Doppler, power mode Doppler, continuous wave Doppler |
|
|
Which two of the following devices convert ultrasound energy into heat |
Hydrophone/Calorimeter |
|
|
The___________ measures beam intensity at the specific locations, where as a _______________ measures the entire energy and a sound wave |
Thermocouple, calorimeter |
|
|
Which of the following is not a potential mechanism for production of bioeffects from ultrasound exposure to the body |
Fractionation |
|
|
Which of these terms best describes the empirical investigation of bioeffects |
Exposure to response time |
|
|
Comprehensive and scholarly review of bioeffects is performed by the American Institute of ultrasound and medicine for all of the reasons except |
Ultrasound is considered highly toxic |
|
|
True or false: the AIUM considers in ultrasound induced biologic tissue temperature rise of less than 2° Centigrade above normal body temperature is safe for clinical studies |
True |
|
|
In studying bioeffects which research approach is more important |
Both mechanistic and empirical |
|
|
Under which condition is it permissible to perform a diagnostic ultrasound exam |
When the benefits outweigh the risks |
|
|
Some ultrasound of bio effect studies are performed in a vevo what is the meaning of in vivo |
Observable in a living body |
|
|
According to the AIUM at what in situ tissue temperature is there a danger to a fetus |
41°C |
|
|
Which is considered the most important for the sonographer with regards to bioeffects |
Duration of the study |
|
|
Which of the following sound beams has a characteristic that’s most likely to cause temperature elevation in soft tissue |
Unfocused |
|
|
Research has indicated that cavitation____________________ |
Can be lethal to living things |
|
|
Which of the following statements regarding cavitation is true |
Stable cavitation relates to oscillating bubbles while transient relates to bursting bubbles |
|
|
Which of the following is related to cavitation bio Effects |
MI |
|
|
Which selection has the highest mechanical index |
Low frequency, high pressure |
|
|
Which sound wave is least likely to Caviation |
6 MHz, two megapascals |
|
|
What is epidemiology The study of |
Prevalence of disease |
|
|
Epidemiologic students of in utero exposure to ultrasound have concluded all of the following findings except |
None of the above |
|
|
Which of the following epidemiologic studies is considered most likely to produce meaningful results |
Prospective and randomized |
|
|
What is the highest SPTA intensity of an on focused ultrasound waves where there has been no observed a bio effects |
100 MW/cm² |
|
|
Certain studies of bio affects are performed in Vitro what is the meaning of in vitro |
Discernible in a test tube |
|
|
Which component of an ultrasound system exposes a patient’s greatest risk |
Transducer |
|
|
Two acoustic beams have identical SPTP intensities of 400 MW/cm². One beam is pulsed while the other is continuous wave. Which beam has the highest SPTA intensity |
Continuous wave |
|
|
The term I sub M defines ________the and has units of____________ |
Maximum intensity, watts per centimeter squared |
|
|
With a continuous wave sound of being which of the following four intensities are the same |
SAPA & SATA |
|
|
The SPTP intensity of a typical pulsed acoustic wave |
Exceeds the SATA intensity exceeds the PSTA exceeds the SATP |
|
|
What does the beam uniformity coefficient measure |
Spatial distribution of sound energy |
|
|
Which of the following values can correctly designate both the duty factor in the beam uniformity coefficient |
100% |
|
|
What is the importance of describing sound beam intensity is in a variety of ways with regard to space and time |
It’s important when studying bio effects |
|
|
True or false: one reason focused ultrasound beams with low intensity’s are less likely to cause bioeffects is it a focused beam is less efficient and heating a large mass of tissue to a critical temperature |
True |
|
|
True or false: focused sound beams are considered less likely to create bioeffects because the beams will strike fewer gas bubbles that could potentially caviate |
True |
|
|
True or false: is generally believed that the ultrasound bioeffects are minimal at intensity levels of those produced by diagnostic imaging appointment |
True |
|