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7 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Sensitivity |
The ability of an imaging system to DETECT WEAK ECHOES. ability of a Doppler system to DETECT WEAK OR SMALL DOPPLER SHIFTS |
Detect weak or small |
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Cavitation |
PRODUCTION OF BUBBLES, two types: STABLE and TRANSIENT. tested in a liquid medium will increase with sufficient pressure AMPLITUDE And FREQUENCY |
Two types |
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Peak Rarefaction pressure |
An increase in RARE-FACTIONAL PRESSURE would cause an INCREASED POSSIBILITY of cavaitations. |
Mechanical index |
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ALARA- As Low As Reasonably Achievable |
Minimum risk while obtaining the necessary diagnostic benefit of ultrasound. The AIUM patient safety standard recommends using minimum output power. |
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Hydrophone |
Ultrasound measuring device used to measure pressure amplitude, pulse waveform and bandwidth. It is able to calculate acoustic pulse parameter. A small transducer element mounted on the end of a needle. Generally, Sonographer outputs are lowest and spectral Doppler outputs are highest. |
Outputs |
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Mechanical index |
An indicator proposed by AIUM that’s related to cavitation. This is equal to the PEAK RAREFACTIONAL PRESSURE divided by the square root of the resonant frequency. MI is higher with higher pressure and lower frequency. |
Cavitation |
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Thermal index |
A number used by the AIUM that related to TIUSSE heating that could be produced by a sound beam. This is equal to transducers output power. Three types of classifications: TIS for soft TISSUE, TIB for bone, TIC for Cranial bone, at skins surface. Unfocused beams are more likely to cause temperature elevation. Tempurature rise of more than 2 degrees is considered significant. |
Unfocused |
