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;
211 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What is the definition of frequency? |
# of cycles per second |
|
|
|
Formula for frequency? |
f=1/p |
|
|
|
Units of frequency? |
Hz MHz 1/sec |
|
|
|
What is frequency determined by? |
Sound source |
|
|
|
What is the definition of period? |
Length of time it takes for 1 cycle to occur |
|
|
|
What is period determined by? |
Sound source |
|
|
|
Units of period? |
Microseconds |
|
|
|
Formula for period? |
T=1/f or P=1/f |
|
|
|
What is wavelength? |
Distance or length of one complete cycle |
|
|
|
What is wavelength determined by? |
Sound source & medium |
|
|
|
Units of wavelength? |
mm |
|
|
|
Formula for wavelength? |
lambda=c/f lambda=upside down Y |
|
|
|
Definition of pulse duration? |
The time of the U.T. pulse (duration) |
|
|
|
What is pulse duration determined by? |
Machine Sound source |
|
|
|
What are the units of pulse duration? |
Microseconds |
|
|
|
Formula for pulse duration? |
PD=# of cycles in pulse x period PD=# of cycles/frequency |
|
|
|
What is the definition of amplitude? |
Bigness of the wave |
|
|
|
What is amplitude determined by? |
Sound source |
|
|
|
What are the units of amplitude? |
Pascals, cm, g/cm3, dB |
|
|
|
What is power determined by? |
Sound source |
|
|
|
What are the units of power? |
Watts |
|
|
|
What is the definition of intensity? |
Concentration of energy in a sound beam |
|
|
|
What is intensity determined by? |
Sound source |
|
|
|
Units of intensity? |
Watts, cm2 |
|
|
|
Formula for intensity? |
Watts/cm2 |
|
|
|
What is the definition of propagation speed? |
Speed at which sound travels in a medium |
|
|
|
What is speed determined by? |
Medium |
|
|
|
Units of speed? |
mm/microsecs m/s |
|
|
|
What is the definition of attenuation? |
Weakening of sound as it travels |
|
|
|
Units of attenuation? |
dB |
|
|
|
Formula of attenuation? |
dB=1/2mHz x cm
|
|
|
|
Definition of spatial pulse length? |
Length or distance of a U.T. pulse |
|
|
|
What is spatial pulse length determined by? |
Medium & sound source |
|
|
|
Units of spatial pulse length? |
mm |
|
|
|
Formula for spatial pulse length? |
SPL(mm)=pulse x wavelength (mm) SPL(mm)=pulse x speed/frequency |
|
|
|
Units of impedance? |
Ralz |
|
|
|
Definition of pulse repetition period? |
Time from inception of one pulse to the inception of the next pulse |
|
|
|
Pulse repetition period is determined by? |
Sound source |
|
|
|
Formula for pulse repetition period? |
PRF= 1/PRP PRP= 1/PRF |
|
|
|
Definition of pulse repetition frequency? |
# of pulses of sound the U.T. transducer emits in 1 sec |
|
|
|
Units of pulse repetition frequency? |
Hz or kHz |
|
|
|
Definition of range? |
Calculates depth of the echo producing structure |
|
|
|
Formula of range? |
D=R x T |
|
|
|
Definition of duty factor? |
Function of time that the U.T. machine is sending out a pulse |
|
|
|
What is duty factor determined by? |
Sound source |
|
|
|
Units of duty factor? |
None |
|
|
|
Formula for duty factor? |
DF= PD/PRP |
|
|
|
Attenuation coefficient? |
Amount of attenuation of sound per cm of travel |
|
|
|
Units of attenuation coefficient? |
dB/cm |
|
|
|
Formula of attenuation coefficient? |
AC(dB/cm)= frequency(MHz)/2 |
|
|
|
The time it takes a wave to vibrate a single cycle, or the time from the start of a cycle to the start of the next cycle is called? |
Period |
|
|
|
The number of particular events that occurs in a specific duration of time is called? |
Frequency |
|
|
|
+3dB |
increases by 2 |
|
|
|
+6dB |
Increases by 4 |
|
|
|
+9dB |
Increases by 8 |
|
|
|
+10dB |
Increases by 10 |
|
|
|
+20dB |
Increases by 100 |
|
|
|
-3dB |
decreases by 1/2 |
|
|
|
-6dB |
Decrease by 1/4 |
|
|
|
-9dB |
Decreases by 1/8 |
|
|
|
-10dB |
Decreases by 1/10 |
|
|
|
-20dB |
Decreases by 1/100 |
|
|
|
List 3 components of attenuation? |
Reflection, absorption, & scatter |
|
|
|
Can duty factor be changed by the sonographer? |
Yes by depth |
|
|
|
True or false: Intensity is indirectly related to the area. |
True |
|
|
|
The discovery that certain materials will deform when placed in a strong electrical field was discovered by which two gentleman? |
Pierre & Jacques Curries |
|
|
|
If you switch from a 5 MHz transducer to a 10 MHz transducer, you will transmit sound at a wavelength that is ______ as long. |
Half |
|
|
|
True or false: In order to be classified as ultrasound, a sound wave must have a frequency of GREATER THAN 20 Hz. |
False |
|
|
|
Which of the following mediums does sound travel slowest? |
Lung |
|
|
|
Place in order of greatest to least propagation speed in soft tissue. Soft tissue, lung, fat, bone |
Bone, soft tissue, fat, lung |
|
|
|
Acoustic velocity of ultrasound in bone? |
4080 m/s |
|
|
|
The number of cycles that an acoustic variable goes through in 1 second of time is? |
Frequency |
|
|
|
Which of the following acoustic parameters of the medium is most important in determining the velocity of sound in the medium? |
Bulk modulus of the medium |
|
|
|
The term “compression zone” refers to what? |
Particle density |
|
|
|
If you switch from a 2.5 MHz transducer to a 5 MHz transducer, you will transmit sound at a wavelength that _____. |
Decreases |
|
|
|
Sound with a frequency of lower that 20 Hertz is called what? |
Infrasound |
|
|
|
If frequency increases, what happens to wavelength? |
Decreases |
|
|
|
If frequency is 7 MHz, what is the period? |
F=7 F=1/p T=1/7 T=? T=7 |
|
|
|
If period is 0.14mm/ms, what is the frequency? |
T= .14 F=1/p F=? F= 1/.14 F=1.4 |
|
|
|
The speed of a 7.5 MHz continuous wave is 1.5 Km/sec. if the wave is then pulsed with a duty factor of .3, what is the speed? |
None of the above |
|
|
|
A linear format will produce what image shape? |
Rectangular |
|
|
|
The product of density of the medium multiplied by the speed of sound is? |
Impedance |
|
|
|
Of sound travels from Medium 1 (low acoustic velocity) into Medium 2 (high acoustic velocity), the frequency of the sound will do what? |
Stay the same |
|
|
|
True or false: Frequency is determined by the sound source only. Not the medium. |
True |
|
|
|
In which medium will sound travel slower? Medium 1 has a density of 9 & stiffness of 6
Medium 2 has a density of 8 & stiffness of 6 |
Medium 1 |
|
|
|
Which of the following will create the fastest speed of sound? High density, high stiffness Low density, high stiffness High density, low stiffness |
Low density, high stiffness |
|
|
|
True or false: Speed increases as frequency increases |
False |
|
|
|
What is the wavelength of a 3 MHz sound in soft tissues? |
Lambda=c/f 1.54MHz / 3= .51mm |
|
|
|
Directly, inversely, or unrelated? Frequency & period |
Inversely |
|
|
|
Directly, inversely, or unrelated? Frequency & period |
Inversely |
|
|
|
Directly, inversely, or unrelated? Wavelength & frequency |
Inversely |
|
|
|
Directly, inversely, or unrelated? Elasticity & speed of sound |
Inversely |
|
|
|
Directly, inversely, or unrelated? Stiffness & sound speed |
Directly |
|
|
|
Directly, inversely, or unrelated? Frequency & sound speed |
Unrelated |
|
|
|
Directly, inversely, or unrelated? Acoustic velocity & density |
Inversely |
|
|
|
Two media A & B have the same densities. A is 10% higher than in medium B. Which medium has the higher acoustic impedance & by how much? |
A; by 10% |
|
|
|
Sound is traveling variations of acoustic variables can you name all 4? |
Pressure, density, particle motion (distance) & temperature |
|
|
|
Define pressure? |
Concentration of force |
|
|
|
Units of pressure? |
Pascals, lbs/sq in, & atmospheres |
|
|
|
Define density? |
Concentration of mass or weight of a material |
|
|
|
Units for density? |
Kilo per cubic cm3 (Kg/cm3) |
|
|
|
Define distance? |
Measurement of particle motion |
|
|
|
Units for distance? |
m, cm, ft |
|
|
|
Describe sound |
Mechanical & longitudinal |
|
|
|
When you have regions of low pressure and density this is called? |
Rarefaction |
|
|
|
When you have regions of high pressure and density this is called? |
Compression |
|
|
|
1 cycle/sec is termed? |
Hertz |
|
|
|
1,000 cycles/sec |
1 kHz 1.0 x 10^3 |
|
|
|
1,000 cycles/sec |
1 kHz 1.0 x 10^3 |
|
|
|
1,000,000 cycles/sec |
1mHz 1.0 x 10^6 |
|
|
|
Frequency is determined by? |
Sound source |
|
|
|
What is sound source? |
Transducer & machine |
|
|
|
Can the sonographer adjust frequency? |
No |
|
|
|
What is the speed of soft tissues? |
1540 m/s 1.54 mm/microseconds |
|
|
|
The number of cycles that an acoustic variable goes through in 1 sec of time is called? |
Frequency |
|
|
|
How is PRP & PRF related? |
They are married, inversely related, & are reciprocals. |
|
|
|
Can sound travel in a vacuum? |
No |
|
|
|
If frequency increases, penetration ________. |
Decreases |
|
|
|
Start of one pulse to start of the next pulse is? |
PRP Pulse repetition period |
|
|
|
Speed of bone is? |
4080 m/s |
|
|
|
How much time does it take for a UT pulse to travel in 1 cm & back in soft tissues? |
13 seconds |
|
|
|
The # of pulses occurring in 1 second is called? |
PRF pulse repetition frequency |
|
|
|
What is the equation for period? |
P=1/f |
|
|
|
What is the equation for frequency? |
F=1/p |
|
|
|
What is the equation for distance? |
D=R x T |
|
|
|
What is the equation for impedance? |
Impedance= density x speed Z= p x c |
|
|
|
What is the equation for pulse duration? |
PD= # of cycles in pulse x period |
|
|
|
What is the equation for SPL? |
SPL(mm) = pulse x wavelength(mm)
SPL(mm)= pulse x speed/ frequency |
|
|
|
What is the equation for intensity? |
Watts/cm2 |
|
|
|
What is the equation for intensity? |
Watts/cm2 |
|
|
|
What is the equation for attention? |
dB=1/2 MHz x cm |
|
|
|
What is the equation for imaging depth? |
Rate x time/2 |
|
|
|
What must sound have to travel in? |
Medium |
|
|
|
Compression? |
An area of increased particle density |
|
|
|
Rarefaction? |
An area of decreased particle density |
|
|
|
What are the 4 acoustic variables? |
Pressure, density, particle motion (distance), temperature |
|
|
|
Infrasound? |
Below range of human hearing LESS than 20Hz |
|
|
|
Infrasound? |
Below range of human hearing LESS than 20Hz |
|
|
|
Audible sound? |
Within the range of human hearing 20-20,000 Hz |
|
|
|
Infrasound? |
Below range of human hearing LESS than 20Hz |
|
|
|
Audible sound? |
Within the range of human hearing 20-20,000 Hz |
|
|
|
Ultrasound? |
Above the range of human hearing GREATER than 20,000 Hz |
|
|
|
What are the 2 properties of the medium? |
Hardness & density |
|
|
|
What are the 2 properties of the medium? |
Hardness & density |
|
|
|
Sound speed in air? |
330 m/s |
|
|
|
What are the 2 properties of the medium? |
Hardness & density |
|
|
|
Sound speed in air? |
330 m/s |
|
|
|
Sound speed in fat? |
1460 m/s |
|
|
|
Sound speed in liver? |
1555 m/s |
|
|
|
Sound speed in muscle? |
1600 m/s |
|
|
|
Sound speed in bone? |
4080 m/s |
|
|
|
Sound speed in bone? |
4080 m/s |
|
|
|
Sound speed in lung? |
500 m/s |
|
|
|
Definition of impedance? |
The resistance that sound encounters in traveling through a medium |
|
|
|
What is the equation of impedance? |
Z=p•c |
|
|
|
What is the equation for range? |
D= R x T |
|
|
|
What is the 13 Microsecond Rule? |
It takes 13 microseconds to travel 1 cm & back in soft tissue |
|
|
|
What determines PRF? |
Sound source |
|
|
|
What are the units of PRP? |
Seconds |
|
|
|
What are the 6 intensity values? |
SPTP SPPA SPTA SATP SAPA SATA |
|
|
|
Definition of spatial? |
Distance or space |
|
|
|
Definition of spatial? |
Distance or space |
|
|
|
Definition of temporal? |
Time |
|
|
|
Definition of peak? |
Maximum |
|
|
|
Definition of average? |
Mean |
|
|
|
What does SPTP equal? |
SPTA |
|
|
|
What does SATP equal? |
SATA |
|
|
|
What happens when sound hits a boundary? |
Transmitted, reflected, scattered, & refracted |
|
|
|
Specular reflection? |
*Smooth* Arise from large smooth boundaries Similar to a reflection in mirror |
|
|
|
What is scattering? |
Occurs when sound encounters irregular, rough, heterogenous, or small boundary tissues Sound is redirected into many directions |
|
|
|
What are the 2 types of scattering? |
Backscatter (returns to transducer) & Rayleigh (redirected in all directions) |
|
|
|
If frequency increases what happens to scatter? |
It increases |
|
|
|
Incident sound? |
Sound that is coming from the sound source & going into the medium |
|
|
|
Transmitted sound? |
The sound that continues to propagate in the direction it was going, after hitting a boundary or interface |
|
|
|
Transmitted sound? |
The sound that continues to propagate in the direction it was going, after hitting a boundary or interface |
|
|
|
Reflected sound? |
The sound that is reflected at the boundary or interface & returns to the transducer |
|
|
|
Perpendicular? |
Sound travels at 90 degrees |
|
|
|
Perpendicular? |
Sound travels at 90 degrees |
|
|
|
Oblique? |
Sound does not encounter the boundary at 90 degrees |
|
|
|
Correct units for density? |
Ibs/cm3 |
|
|
|
Range for ultrasound? |
Greater than 20kHz |
|
|
|
The useful frequency range for clinical imaging ultrasound is? |
2 MHz to 10 MHz |
|
|
|
Wavelength of a 5 MHz probe in soft tissues is? |
.3mm |
|
|
|
The period for a 5 MHz probe is? |
.2 microsecs |
|
|
|
Period multiplied by the number of cycles in a pulse equals? |
Pulse duration |
|
|
|
Units for amplitude? |
Degrees, dB, Pascals |
|
|
|
The rate of energy transferred into a particular area is? |
Intensity |
|
|
|
Units for intensity? |
Watts/cm2 |
|
|
|
Reflection will occur at the boundary of 2 media if the media impedances are? |
Dissimilar |
|
|
|
The incidence angle is 36 degrees. The reflected angle is? |
36 degrees |
Reflected angle is always equal to incidence angle |
|
|
The best example of a Rayleigh scatter is? |
Red blood cell |
|
|
|
The ultrasound beam strikes an interface at 90 degrees. The incidence is considered? |
Perpendicular |
|
|
|
The amplitude of a wave is 4. Power is? |
16 |
Intensity=P/area = A2 When A=4 I on power=16 |
|
|
Which unit is used to express aortic valve area? |
Cm2 |
|
|
|
What happens to sound when it’s absorbed (what does it turn into)? |
Heat |
|
|
|
When does more absorption take place when using a transducer with a? |
Higher frequency transducer |
|
|
|
What is intensity indirectly related to? |
Area |
|
|
|
With B Mode, the brightness of the dot is proportional to what? |
Strength of the reflected or echo signal amplitude |
|
|
|
With B Mode, the brightness of the dot is proportional to what? |
Strength of the reflected or echo signal amplitude |
|
|
|
What does intensity reflection coefficient mean? |
The % of sounds intensity that is reflected |
|
|
|
True or false: The path length remains the same; increasing frequency will have a decreasing attenuation? |
False |
|
|
|
List 3 components of attenuation: |
Absorption Reflection Scatter |
|
|
|
Sound with a frequency of lower than 20 Hz is called ___ |
Infrasound |
|
|
|
What is the purpose of using harmonica in relation to the benefit manifested in ultrasonic images? |
Makes the image better |
|
|
|
When the frequency of sound is changed due to movement, in relation to the sound source and the reflector of sound, we term this the ____ ____. |
Doppler effect |
|
|
|
When the frequency of sound is changed due to movement, in relation to the sound source and the reflector of sound, we term this the ____ ____. |
Doppler effect |
|
|
|
Name two methods (formats) utilized to present Doppler information to the observer. |
Pulse wave Color Doppler Audible Echo Waveform |
|
|
|
How much time is required for an ultrasound pulse to travel 1 cm and back in soft tissue? |
13 microseconds |
|
|
|
_____ _____ is the time from the start of a pulse to the end of that pulse. |
Pulse duration |
|
|
|
Pulse repetition frequency is the reciprocal of what? |
Pulse repetition period |
|
|
|
The speed of a 5MHz continuous wave is 1.8 km/sec. The wave is then pulsed with a duty factor of 0.5. Calculate the new propagation speed. |
Stays the same
Medium never changed |
|
