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22 Cards in this Set
- Front
- Back
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What is the go-return time?
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The time from pulse creation to pulse reception
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What is the pulse repetition period (PRP)?
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The time from the start of one pulse to the start of the next pulse
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Beyond their definitions, what is the difference between the go-return time and PRP?
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There is none
(The formula for depth in Edelman, P. 106 uses go-return time. This same formula is solved for time, using units of cm instead of mm, and with PRP substituted for go-return time, in Edelman, P. 107.) |
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What is the speed of sound in soft tissue
a) in m/sec? b) in mm/microsec? |
a) 1540 m/sec
b) 1.54 mm/microsec |
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What is the formula for depth, expressed in terms of go-return time?
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Depth (mm) = (1.54 mm/microsec) x (go-return time (microsec) / 2)
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What is the formula for PRP, expressed in terms of depth?
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PRP (microsec) = (imaging depth (cm) x 13 microsec/cm)
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What is the go-return time to an object which is 1 cm deep in soft tissue?
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13 microseconds
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What is the PRP when the imaging depth is set to view an object which is 1 cm deep in soft tissue?
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13 microseconds
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What is the formula for PRF, expressed in terms of depth?
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PRF (Hz) = (77,000 cm/sec) / imaging depth (cm)
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What are the six major components of an ultrasound system?
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1. Transducer
2. Pulser and beam former 3. Receiver 4. Display 5. Storage 6. Master synchronizer |
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What are the 5 functions of the receiver?
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1. Amplification
2. Compensation 3. Compression 4. Demodulation 5. Rejection |
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Which functions of the receiver are operator-dependent?
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Except for demodulation, all are operator-dependent
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What is a synonym for amplification?
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Receiver gain
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What is the purpose of compensation?
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To correct for attenuation at various depths.
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What are the two purposes of compression?
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1. To keep an image's grayscale content within the range of detection of the human eye
2. To keep the electrical signal levels within the accuracy range of the system's electronics |
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What is a synonym for compression?
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Dynamic range
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What is the purpose of demodulation?
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To change the electrical signals into a form more suitable for CRT display
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What are the two parts of demodulation?
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1. Rectification (converting all negative voltages into positive voltages)
2. Smoothing (eliminating small "bumps" in the voltage signal) |
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What is the difference between amplification and compensation?
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Amplification processes all signals identically.
Compensation allows for different treatments to be applied to signals originating at different depths. |
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What function of an ultrasound system is exclusively dedicated to boosting signal loss due to attenuation?
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Compensation
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What components of an ultrasound system can utilize compression?
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1. Receiver
2. Scan converter 3. Monitor |
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What is the function of the pulser?
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To create electrical signals to excite the transducer's PZT crystals.
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