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