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202 Cards in this Set
- Front
- Back
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T/F
ALL NUMERICAL VALUES SHOULD HAVE CORRESPONDING UNITS. |
TRUE
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WHAT ARE THE UNITS OF VOLUME?
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cm3, ft3,
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T/F
PERCENT IS A UNIT |
FALSE
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WHAT IS THE MEANING, PREFIX, AND SYMCOL FOR THE FOLLOWING:
1.10^9 2. 10^6 3. 10^3 4. 10^-3 |
1. BILLION-GIGGA- G
2. MILLION-MEGA- M 3. THOUSAND-KILO-k 4. THOUSANDTH-MILLI-m |
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THESE ARE KNOWN AS "THE EEFECTS OF THE MEDIUM UPON THE SOUND WAVE"
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ACOUSTIC PROPAGATION PROPERTIES.
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THESE ARE KNOWN AS " THE EFFECTS OF THE SOUND WAVE UPON THE BIOLOGIC TISSUE"
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BIOLOGIC EFFECTS
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DESCRIBE BOTH COMPRESSIONS AND RAREFACTIONS IN SOUND.
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COMPRESSIONS: INCREASES IN PRESSURE OR DENSITY
RAREFACTIONS: DECREASES IN PRESSURE OR DENSITY. |
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T/F
SOUND MUST TRAVEL THROUGH A MEDIUM, IT CAN NOT TRAVEL THROUGH A VACUUM. |
TRUE
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T/F
SOUND DOES NOT TRAVEL IN A STRAIGHT LINE. |
FALSE
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WHAT ARE THE UNITS OF PRESSURE?
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PASCALS (Pa)
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LIST THE 7 PARAMETERS THAT DESCRIBE SOUND WAVES:
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1.PERIOD
2.FREQUENCY 3.AMPLITUDE 4.POWER 5.INTENSITY 6.SPEED 7.WAVELENGTH |
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WHAT ARE THE THREE ACOUSTIC VARIABLES?
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1.PRESSURE
2. DENSITY 3. DISTANCE |
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CONCENTRATION OF FORCE WITH IN AN AREA?
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PRESSURE
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MEASURE OF PARTICLE MOTION?
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DISTANCE
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CONCENTRATION OF MASS WITH IN AN OBJECT?
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DENSITY
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THESE INFORM US WHICH WAVES ARE SOUND WAVES.
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ACOUSTIC VARIABLES
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THESE DESCRIBE THE FEATURES OF A PARTICULAR SOUND WAVE.
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ACOUSTIC PARAMETERS
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DEFINED AS " THE TIME REQUIRED TO COMPLETE ONE CYCLE "
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PERIOD
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NUMBER OF CERTAIN EVENTS THAT OCCUR IN A PARTICULAR TIME DURATION.
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FREQUENCY
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WHAT ARE THE UNITS FOR FREQUENCY?
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HERTZ (Hz) (PER SECOND)
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T/F
FREQUENCY AFFECTS PENETRATION AND AXIAL RESOLUTION. (IMAGE QUALITY) |
TRUE
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WHAT ARE THE TYPICAL VALUES OF FREQUENCY?
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2MHz-10MHz
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A WAVE WITH A FREQUENCY EXCEEDING 20,000 Hz (20kHz). SO HIGH THAT IT IS NOT AUDIBLE.
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ULTRASOUND
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HEARD BY MAN, FREQUENCIES BETWEEN 20Hz-20,000Hz.
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AUDIBLE SOUND
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SOUND WITH FREQUENCIES LESS THAN 20Hz. SO LOW THAT IS NOT AUDIBLE.
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INFRASOUND
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AS FREQUENCY increases PERIOD_______.
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DECREASES
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FREQUENCY (Hz) X PERIOD (sec) =________.
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1
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LIST THE THREE "BIGGNESS PARAMETERS"
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AMPLITUDE, POWER, INTENSITY.
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THE DIFFERENCE BETWEEN THE AVERAGE VALUE AND THE MAXIMUM VALUE OF AN ACOUSTIC VARIABLE.
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AMPLITUDE
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WHAT ARE THE UNITS OF AMPLITUDE?
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THOSE OF THE ACOUSTIC VARIABLES. (PRESSURE, DENSITY, PARTICLE MOTION)
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WHAT ARE THE UNITS OF THE THREE ACOUSTIC VARIABLES?
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PRESSURE- PASCALS
DENSITY- GRAMS/CUBIC cm PARTICLE MOTION- cm, inches, units of distance |
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T/F
AMPLITUDE MAY BE EXPRESSED IN DECIBELS, dB. |
TRUE
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AMPLITUDE ________ AS SOUND PROPAGATES THROUGH THE BODY.
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DECREASES
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WHAT IS THE DIFFERENCE BETWEEN THE MAXIMUM AND MINIMUM VALUES OF AN ACCOUSTIC VARIABLE KNOWN AS?
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PEAK-TO-PEAK AMPLITUDE
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THE RATE THAT WORK IS PERFORMED, OR THE RATE OF ENERGY TRANSFER IS KNOWN AS:
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POWER
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WHAT ARE THE UNITS OF POWER?
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WATTS
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POWER ________ AS SOUND PROPAGATES THROUGH THE BODY.
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DECREASES
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WHAT IS THE RELATIONSHIP BETWEEN POWER AND AMPLITUDE?
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POWER IS PROPORTIONAL TO THE WAVE'S AMPLITUDE SQUARED
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THE CONCENTRATION OF ENERGY IN A SOUND BEAM.
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INTENSITY
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WHAT IS THE EQUATION OF INTENSITY?
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POWER (watts) /
BEAM AREA (cm^2) |
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INTENSITY ________ AS SOUND PROPAGATES THROUGH THE BODY.
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DECREASES
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AS INTENSITY INCREASES, POWER ____________.
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INCREASES
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AS WELL AS POWER, INTENSITY IS PROPORTIONAL TO__________.
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AMPLITUDE SQUARED.
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THE LENGTH OR DISTANCE OF A CYCLE IS KNOWN AS:
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WAVELENGTH
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WHAT ARE THE UNITS OF WAVELENGTH?
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ANY UNIT OF LENGTH (METERS, mm)
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T/F
WAVELENGTH IS DETERMINED BY BOTH THE SOURCE AND THE MEDIUM. |
TRUE. ( ONLY ONE THAT IS DETERMINED BY BOTH )
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WHAT IS THE FORMULA FOR WAVELENGTH?
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=PROPAGATION SPEED / INTENSITY
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L=C/F <--------- WHAT DOES THIS FORMULA REFER TO?
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WAVELENGTH
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HIGHER FREQUENCY = ?
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SHORTER WAVELENGTH
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LOWER FREQUENCY =?
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LONGER WAVELENGTH
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IN SOFT TISSUE, SOUND WITH A FREQUENCY OF 1MHz HAS A WAVELENGTH OF____________.
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1.54mm
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AS A RULE : DIVIDE ______ BY FREQUENCY IN______ TO AQUIRE THE WAVELENGTH IN SOFT TISSUE.
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1.54mm, MHz ( PAY ATTENTION TO THE UNITS!!!!)
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THE RATE THAT SOUND TRAVELS THROUGH A MEDIUM IS KNOWN AS:
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PROPAGATION SPEED
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WHAT IS THE AVERAGE SPEED OF ALL SOUND (REGAURDLESS OF FREQUENCY) IN BIOLOGIC OR "SOFT TISSUE"
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1.54km/s=1,540m/s=1.54mm/us
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WHAT IS THE INCREASING ORDER OF THE SPEED IN SPECIFIC MEDIUMS?
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LUNG (AIR)<<FAT<SOFT TISSUE<<BONE
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WHAT ARE THE PROPAGATION SPEEDS OF THE FOLLOWING?:
AIR, BLOOD (SOFT TISSUE), TENDON |
AIR- 330 m/s
BLOOD (ST)- 1540m/s TENDON- 1850m/s |
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STIFFNESS AND SPEED TRAVEL________ DIRECTION. WHILE DENSITY AND SPEED TRAVEL_______ DIRECTION.
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SAME, OPPOSITE
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BULK MODULUS IS ________ AS STIFFNESS.
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THE SAME
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WHAT IS THE EQUATION FOR SPEED?
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FREQUENCY (Hz) x WAVELENGTH (meters)
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THE ONLY ONE OUT OF THE 7 PARAMETERS THAT IS DETERMINED BY ONLY THE MEDIUM IS:
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SPEED
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WHEN TWO WAVES "INTERFERE", THEY ARE KNOWN AS ONE OF TWO THINGS:
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IN PHASE AND OUT OF PHASE.
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WHEN THE AMPLITUDE OF THE NEW, COMBINED WAVE, IS LARGER THAN EITHER TWO OF THE ORIGINAL WAVES, THIS IS KNOWN AS:
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CONSTUCTIVE INTERFERENCE.
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WHEN THE AMPLITUDE OF THE NEW WAVE IS LESS THAN ONE OF THE ORIGINAL WAVES, THIS IS KNOWN AS:
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DESTRUCTIVE INTERFERENCE
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IN-PHASE WAVES INTERFERE__________, WHILE OUT OF PHASE WAVES INTERFERE________.
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CONSTRUCTIVELY, DESTRUCTIVELY
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IN DIAGNOSTIC ULTRASOOUND IMAGING, SHORT BURSTS, OR _____ , OF ____ ______ ARE USED TO CREATE ANATOMIC IMAGES.
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PULSES; ACOUSTIC ENERGY.
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A COLLECTION OF CYCLES THAT TRAVEL TOGETHER IS KNOWN AS:
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A PULSE
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WHAT ARE THE TWO COMPONETS OF PULSED ULTRASOUND?
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THE CYCLES (ON, TRANSMIT TIME)
THE DEAD TIME (OFF OR RECEIVE TIME) |
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WHAT ARE THE FIVE ADDITIONAL PARAMETERS OF PULSED ULTRASOUND?
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PULSE DURATION
PRP PRF DUTY FACTOR SPL |
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THE TIME FROM THE START OF A PULSE TO THE END OF THAT PULSE , THE ACTUAL TIME THE PULSE IS ON:
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PULSE DURATION
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IN CLINICAL IMAGING, A PULSE IS COMPRISED OF HOW MANY CYCLES?
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2-4
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WHAT IS THE EQUATION FOR PULSE DURATION?
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# OF CYCLES IN PULSE* PERIOD
# OF CYCLES IN PULSE/ FREQUENCY |
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THE TIME FROM THE START OF ONE PULSE TO THE START OF THE NEXT PULSE IS KNOWN AS:
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PRP
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AS IMAGING DEPTH INCREASES, PRP_____.
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INCREASES
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THE NUMBER OF PULSES THAT OCCUR IN ONE SECOND:
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PRF
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PRF IS (RELATED/UNRELATED) TO FREQUENCY?
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UNRELATED
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PRF DEPENDS ONLY UPON:
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IMAGING DEPTH
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WHAT TYPE OF RELATIONSHIP DO IMAGING DEPTH AND PRF HAVE?
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INVERSE (WHEN ONE INCREASES THE OTHER DECREASES)
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WHAT IS THE RELATIONSHIP BETWEEN PRF AND PRP?
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INVERSE
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THE PERCENTAGE OR FRACTION OF TIME THAT THE SYSTEM TRANSMITS SOUND:
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DUTY FACTOR
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WHAT ARE THE UNITS OF DUTY FACTOR?
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UNITLESS!
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T/F
CONTINUOUS WAVE SOUND CANNOT BE USED TO MAKE ANATOMICAL IMAGES. |
TRUE
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WHAT IS THE EQUATION FOR DUTY FACTOR?
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PULSE DURATIN / PRP*100
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THE DISTANCE FROM THE START TO THE END OF ONE PULSE:
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SPATIAL PULSE LENGTH
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WHAT IS THE EQUATION FOR SPL?
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SPL= #OF CYCLES * WAVE LENGTH
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THE CONCENTRATION OF THE POWER IN A BEAM:
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INTENSITY
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WHAT ARE THE UNITS OF INTENSITY?
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W/CM^2
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PEAK:
AVERAGE: SPATIAL: TEMPORAL: PULSE: |
1. MAXIMUM VALUE
2. THE MEAN VALUE 3. REFERING TO DISTANCE OR SPACE 4. REFERING TO ALL TIME 5. REFERING ONLY TO THE TIME THE PULSE EXISTS |
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WHAT DOES SPTA STAND FOR?
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SPATIAL PEAK, TEMPORAL AVERAGE
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WHAT DOES SATA STAND FOR?
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SPATIAL AVERAGE, TEMPORAL AVERAGE
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WHAT DOES SPPA STAND FOR?
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SPATIAL PEAK, PULSE AVERAGE.
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WHAT DOES SAPA STAND FOR?
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SPATIAL AVERAGE, PULSE AVERAGE.
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T/F
INTENSITIES MAY BE REPORTED IN VARIOUS WAYS, WITH RESPECT TO TIME AND SPACE. |
TRUE
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______ INTENSITY IS THE MOST RELEVANT INTENSITY WITH RESPECT TO TISSUE HEATING.
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SPTA
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ALL INTENSITIES HAVE UNITS OF___________.
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WATTS/CM^2
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______INTENSITY HAS THE HIGHEST VALUE. ________ INTENSITY HAS THE LOWEST VALUE.
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SPTP. SATA
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A # CALLED THE ____ ______ ______ (ALSO CALLED SP/SA FACTOR) DESCRIBES THE SREAD OF A BEAM IN SPACE. IT IS A UNITLESS NUMBER WITH A VALUE OF 1 OR GREATER.
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BEAM UNIFORMITY COEFFICIENT
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THE _____ _____ DESCRIBES THE RELATIONSHIP OF BEAM INTENSITIES WITH RESPECT TO TIME. IT IS A UNITLESS NUMBER WITH A VALUE BETWEEN 0 AND 1.
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DUTY FACTOR
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WHEN PW AND CW HAVE THE SAME SPPA INTENSITIES, THE CW HAS THE HIGHER _________ INTENSITY
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SPTA
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WHEN PW AND CW HAVE THE SAME SAPA INTENSITIES, THE CW HAS THE HIGHER _________INTENSITY.
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SATA
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AN EASY WAY TO REMEMBER THE LOGARITHM OF A SPECIFIC NUMBER IS TO:
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COUNT THE ZEROS
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WHEN YOU SEE THESE TWO WORDS WHEN DEALING WITH UNITS, THE UNITS ARE dB.
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COMPARITVE....RELATIVE
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POSSITIVE dB MEANS GETTING BIGGER, THUS THE INTENSITY IS:
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INCREASING
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3dB MEANS:
10dB MEANS: |
2 TIMES BIGGER
10 TIMES BIGGER |
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NEGATIVE dB MEANS GETTING SMALLER, THUS INTENSITY WILL:
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DECREASE
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-3dB MEANS:
-10 dB MEANS: |
ONE HALF
ONE TENTH |
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AS SOUND TRAVELS IT GETS WEAKER AND WEAKER:
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ATTENUATION
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WHAT ARE THE UNITS OF ATTENUATION?
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dB (MUST BE NEGATIVE)
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ATTENUATION OF SOUND IN SOFT TISSUE DEPENDS UPON THE WAVE'S : (2 THINGS)
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1. DISTANCE
2. FREQUENCY |
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WHAT ARE THE THREE COMPONETS OF ATTENUATION?
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1. ABSORPTION
2. SCATTERING 3. REFLECTION |
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WHY DO WE USE GEL IN U/S?
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TO REMOVE AIR FROM THE PATH OF ULTRASOUND.
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ATTENUATION OF SOUND IN BLOOD IS APPROXIMATELY ________ TO THAT IN SOFT TISSUE.
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EQUAL
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ATTENUATION IS __________ TO PROPAGATION SPEED.
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UNRELATED
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OCCURS WHEN PROPAGATING SOUND ENERGY STRIKES A BOUNDARY BETWEEN TWO MEDIA AND SOME RETURNS TO THE TRANSDUCER.
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REFLECTION
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IF THE BOUNDARY BETWEEN TWO MEDIA HAS IRREGULARITIES, THEN THE WAVE MAY BE CHAOTICALLY REDIRECTED IN ALL DIRECTIONS.
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SCATTERING
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IF A REFLECTOR IS MUCH SMALLER THAN THE WAVELENGTH OF SOUND, THE SOUND IS UNIFORMLY DIVERTED IN ALL DIRECTIONS.
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RAYLEIGH SCATTERING.
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RAYLEIGH SCATTERING IS RELATED TO_________.
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FREQUENCY
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T/F
ATTENUATION ULTIMATELY LIMITS THE MAXIMUM DEPTH FROM WHICH MEANINGFUL REFLECTIONS ARE OBTAINED. |
TRUE
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THE AMOUNT OF ATTENUATION PER CENTIMETER IS KNOWN AS THE:
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ATTENUATION COEFFICIENT
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WHAT ARE THE UNITS OF ATTENUATION COEFFICIENT?
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dB/cm
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IN SOFT TISSUE THE ATTENUATION COEFF. IS APROX. __________ OF THE FREQUENCY.
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ONE HALF
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IS A CHARECTERISTIC OF THE MEDIUM ONLY AND IS CALCULATED, NOT MEASURED.
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IMPEDANCE
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WHAT ARE THE UNITS OF IMPEDANCE?
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RAYLS (Z)
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REFLECTION OF AN ULTRASOUND WAVE DEPENDS ON:
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DIFFERENT ACOUSTIC IMPEDANCES OF THE MEDIA ON EITHER SIDE OF THE BOUNDARY.
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ANOTHER PHRASE FOR "NORMAL INCIDENCE" AND "ORTHOGONAL" IS :
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RIGHT ANGLE
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WHAT IS OBLIQUE INCIDENCE?
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ANYTHING OTHER THAN 90 DEGREES
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WITH OBLIQUE INCIDENCE, INCIDENT INTENSITY=?
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TRANSMITTED +REFLECTED
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WITH OBLIQUE INCIDENCE:
REFLECTION ANGLE=? |
INCIDENT ANGLE
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TRANSMISSION WITH A BEND, IS KNOWN AS:
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REFRACTION
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REFRACTION OCCURES WHEN TWO CONDITIONS ARE MET:
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1. OBLIQUE INCIDENCE
2. DIFFERENT PROPAGATION SPEEDS |
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THE PHYSICS OF REFRACTION ARE DESCRIBED BY:
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SNELL'S LAW
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WHAT IS THE EQUATION ASSOC. WITH SNELL'S LAW?
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SINE(TRANSMISSION ANGLE)/SINE (INCIDENT ANGLE) = PROP SPEED 1/PROP SPEED 2.
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THE TIME NEEDED FOR A PULSE TO TRAVEL TO AND FROM THE TRANSDUCER AND THE REFLECTOR IS CALLED:
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GO-RETURN TIME OR TIME OF FLIGHT
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WHAT IS THE 13 MICROSECOND RULE?
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IN SOFT TISSUE, EVERY 13 MICROSECONDS OF GO-RETURN TIME MEANS THE REFLECTOR IS 1cm DEEPER IN THE BODY.
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ANY DEVICE THAT CONVERTS ONE FORM OF ENERGY TO ANOTHER
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TRANSDUCER
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A PROPERTY OF CERTAIN MATERIALS TO CREATE A VOLTAGE WHEN THEY ARE MECHANICALLY DEFORMED.
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PIEZOELECTRIC EFFECT
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MATERIALS DEFORM OR CHANGE SHAPE WHEN A VOLTAGE IS APPLIED TO THEM.
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REVERSE PIEZOELECTRIC EFFECT.
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ANOTHER WORD FOR PIEZOELECTRIC MATERIALS
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FERROELECTRIC MATERIAL
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WHAT DOES "PZT" STAND FOR?
|
LEAD ZIRCONATE TITANATE
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NAME THREE OTHER WORDS PZT COULD BE REFERED TO AS.
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CERAMIC, ACTIVE ELEMENT, CRYSTAL.
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WHAT IS THE CURIE TEMP?
|
360 DEGREES C OR 680 DEG. F
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T/F
IT IS OK TO STERILIZE A TRANSDUCER. |
FALSE. (DISINFECT)
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IT IS 1/2 WAVELENGTH THICK.
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ACTIVE ELEMENT
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THIS MAKES A SHORT PULSE WHICH MAKES A BETTER IMAGE.
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DAMPING ELEMENT OR BACKING MATERIAL
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NAME 2 ADVANTAGES OF DAMPING MATERIAL.
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-SHORTENS SPL, PULSE DURATION
-INCREASES PIC ACCURACY BY IMPROVING AXIAL RESOLUTION. |
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NAME 3 CHARECTERISTICS OF BACKING MATERIAL:
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-DECREASED OUTPUT POWER
-DECREASED TRANSDUCER SENSITIVITY -DECREASED "Q" FACTOR |
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RANGE OF FREQUENCIES BETWEEN THE HIGHEST AND THE LOWEST FREQ. EMITTED FROM THE TRANSDUCER.
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BANDWIDTH
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A UNITLESS NUMBER REPRESENTING THE EXTENT OF DAMPING.
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QUALITY FACTOR
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SOUND WAVE'S FREQUENCY = THE FREQUENCY OF THE VOLTAGE APPLIED TO THE PZT BY THE MACHINE'S ELECTRONICS. IS A CHARECTERISTIC OF:
|
CONTINUOUS WAVE TRANSDUCERS
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THE CENTER FREQUENCY IN PULSED TXRS IS DETERMINED BY 2 CHARECTERISTICS OF THE CRYSTAL:
|
-THE THICKNESS
-THE PROP. SPEED OF THE PIEZOELECTRIC MATERIAL |
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THE PROP SPEED FOR PZT IS APROX:
|
4-6mm PER SECOND
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2 CHARECTERISTICS OF A HIGH FREQUENCY TXR:
|
-THIN CRYSTAL
-FAST PZT |
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NARROW BEAMS=??
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BETTER IMAGES
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LOCATION WHERE THE BEAM REATCHES IT'S MINIMUM DIAMETER
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FOCUS OR FOCAL POINT
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NAME 2 ADVANTAGES OF DAMPING MATERIAL.
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-SHORTENS SPL, PULSE DURATION
-INCREASES PIC ACCURACY BY IMPROVING AXIAL RESOLUTION. |
|
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-DECREASED OUTPUT POWER
-DECREASED TRANSDUCER SENSITIVITY -DECREASED "Q" FACTOR |
BACKING MATERIAL
|
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RANGE OF FREQUENCIES BETWEEN THE HIGHEST AND THE LOWEST FREQ. EMITTED FROM THE TRANSDUCER.
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BANDWIDTH
|
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A UNITLESS NUMBER REPRESENTING THE EXTENT OF DAMPING.
|
QUALITY FACTOR
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SOUND WAVE'S FREQUENCY = THE FREQUENCY OF THE VOLTAGE APPLIED TO THE PZT BY THE MACHINE'S ELECTRONICS. IS A CHARECTERISTIC OF:
|
CONTINUOUS WAVE TRANSDUCERS
|
|
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THE CENTER FREQUENCY IN PULSED TXRS IS DETERMINED BY 2 CHARECTERISTICS OF THE CRYSTAL:
|
-THE THICKNESS
-THE PROP. SPEED OF THE PIEZOELECTRIC MATERIAL |
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THE PROP SPEED FOR PZT IS APROX:
|
4-6mm PER SECOND
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2 CHARECTERISTICS OF A HIGH FREQUENCY TXR:
|
-THIN CRYSTAL
-FAST PZT |
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NARROW BEAMS=??
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BETTER IMAGES
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LOCATION WHERE THE BEAM REATCHES IT'S MINIMUM DIAMETER
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FOCUS OR FOCAL POINT
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FOCAL DEPTH IS DETERMINED BY 2 FACTORS:
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-TRANDUCER DIAMETER
-FREQUENCY OF THE US |
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SOUND BEAM DIVERGENCE IS DETERMINED BY 2 FACTORS:
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-TRANSDUCER DIAMETER
-FREQUENCY OF US |
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WHEN PRODUCED BY A TINY SOURCE, WITH A SIZE NEAR THE WAVELENGTH OF THE SOUND, WAVES WILL MAKE THIS SHAPE AS THEY PROPAGATE.
|
V-SHAPED WAVE, ALSO CALLED HUYGEN'S WAVELET.
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|
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THIS EXPLAINS THE HOURGLASS SHAPE OF AN IMAGING TX'S SOUND BEAM.
|
HUYGEN'S PRINCIPLE
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THE ABILITY TO DISTINGUISH TWO STRUCTURES THAT ARE CLOSE TO EACH OTHER FRONT TO BACK, PARALLEL TO, OR ALONG THE BEAM'S AXIS.
|
AXIAL RESOLUTION
|
|
|
WHAT DOES "LARRD" STAND FOR?
|
LONGITUDINAL
AXIAL RANGE, RADIAL DEPTH |
|
|
SHORTER PULSES PROVIDE BETTER _______ RESOLUTION?
|
"LARRD"
|
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CAN AXIAL RESOLUTIN BE CHANGED BY THE SONOGRAPHER?
|
NO, TX IS NEEDED
|
|
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AXIAL RESOLUTION IS BEST IN TRX WITH:
|
-HIGHER FREQUENCY
-FEWEST # OF CYCLES PER PULSE. |
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|
THE MINIMUM DISTANCE THAT TWO STUCTURES ARE SEPERATED BY SIDE-TO-SIDE OR PERPENDICULAR TO THE SOUND BEAM THAT PRODUCES TWO DISTINCT ECHOES.
|
LATERAL RESOLUTION
|
|
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WHAT DOES "LATA" STAND FOR ?
|
LATERAL
ANGULAR TRANSVERSE AZIMUTHAL |
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LATERAL RESOLUTIN IS APPROXIMATELY EQUAL TO:
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BEAM DIAMETER
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LATA RESOLUTON IS USUALLY NOT AS GOOD AS LARRD RESOLUTION BECAUSE:
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US PULSES ARE WIDER THAN THEY ARE SHORT.
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WHERE DOES HIGH FREQUENCY US IMPROVE LARRD RESOLUTION? LATA RESOLUTION?
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LARRD-EVERYWHERE IN THE IMAGE
LATA-FAR FIELD ONLY |
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FOCUSING ALTERS BEAMS IN WHAT THREE WAYS?
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1. NARROWER WAIST IN THE US BEAM
2. SHALLOWER FOCUS 3. SMALLER FOCAL ZONE |
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PHASED ARRAY MEANS:
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"ADJUSTABLE" OR "MULTI-FOCUSING"
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"A-MODE" STANDS FOR?
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AMPLITUDE MODE
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Y-AXIS IN A-MODE IS:
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THE AMPLITUDE OF THE ECHO, MEASURED BY ECHO STRENGTH
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B-MODE STANDS FOR?
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BRIGHTNESS MODE
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RETURING ECHOES ARE PRESENTED AS SPOTS ON THE LINE OF TRAVEL OF THE EMITTED US PULSE.
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B-MODE SCANNING
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THE X-AXIS ON B-MODE IS:
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REFECTOR DEPTH MEASURED BY PULSE'S TIME-OF-FLIGHT
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THE Z-AXIS ON B-MODE IS:
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AMPLITUDE OF ECHOES MEASURED BY ECHO STRENGTH
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M-MODE STANDS FOR:
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MOTION MODE
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_____IS THE ONLY MODE THAT DISPLAYS THE CHANGEING POSITION OF REFLECTORS WITH RESPECT TO TIME.
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M-MODE
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IN M-MODE:
X-AXIS - ?? Y-AXIS - ?? |
X- TIME
Y- REFLECTOR DEPTH MEASURED BY PULSE'S TOF |
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2-D IMAGES MAY BE REFERED TO AS _____ OR _____ SINCE THEY ARE GRAY SCALE.
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B-SCANNS OR B-MODES
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MECHANNINCAL SCANNING, WHAT SHAPE IS THE PZT?
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CIRCULAR AND DISC SHAPPED (LIKE A COIN)
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IN MECHANICAL IMAGING, WHAT IS THE IMAGE SHAPE?
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FAN OR SECTOR SHAPED
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SWITCHED ARRAYS ARE ALSO CALLED?
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SEQUENTIAL ARRAYS
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ADJUSTABLE FOCUS OR MULTI-FOCUS; THESE ARE ACHIEVED ELECTRONICALLY:
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PHASED ARRAYS
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A CONVEX OR "D-SHAPED FIRING PATTEREN" CREATES A___________
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DEFOCUSED OR DIVERGENT BEAM
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THE ______ ________ OF THE SYSTEM CREATES THESE ELECTRONIC PATTERNS. DELAYS ARE APPROX. 10 NANOSECONDS.
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BEAM FORMER
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T/F
LATERAL RESOLUTION IS BETTER WITH PHASED ARRAY. |
TRUE
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ARRAY LOOKS LIKE A "BULL'S EYE" TARGET
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ANNULAR PHASED ARRAY
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STEERING THIS ARRAY TRANSDUCER, IS PERFORMED MECHANICALLY. THIS IS UNLIKE OTHER PHASED ARRAY TRX'S.
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ANNULAR PHASED ARRAY
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WHAT IS USED FOR 4D IMAGING ?
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2D ARRAY
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NAME THE 7 TYPES OF TRANSDUCERS:
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MECHANICAL
LINEAR SWITCHED LINEAR PHASED ARRAY ANNULAR PHASED CONVEX SEQUENTIAL CONVEX PHASED VECTOR |
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*STUDY TANSDUCER CHART*!!!!!!
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*STUDY TRNSDUCER CHART*!!!
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ACOUSTIC IMPEDANCE=
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DENSITY (kg/m^3) X propagation speed (m/s)
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