Term
| Format using multiple pulses sent from one starting point that travel in the same direction, creating vertical parallel scan lines. |
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Definition
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Term
| Format using multiple pulses sent from the same starting point that travel in slightly different directions. |
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Definition
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Term
| Format using multiple pulses sent from different starting points along a curved line. |
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Definition
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Term
| Measures the change in frequency of moving objects. |
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Definition
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Term
| Color doppler measures the _______ velocity of blood flow. |
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Definition
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Term
| Spectral doppler measures the _______ velocity of blood flow. |
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Definition
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Term
| Time for one cycle to occur. |
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Definition
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Term
| Relationship between period and frequency. |
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Definition
| Reciprocals (inversely related) |
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Term
| Number of cycles that occur in one second. |
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Definition
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Term
| Measurement of signal strength. |
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Definition
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Term
| Concentration of energy in a sound beam. |
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Definition
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Term
| Part of the sound beam with the highest intensity. |
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Definition
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Term
| Length of one complete cycle. |
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Definition
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Term
| The only parameter of waves determined by the medium and the source. |
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Definition
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Term
| Wavelength determines ______ resolution. |
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Definition
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Term
| The ________ the wavelength, the better the resolution. |
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Definition
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Term
| Wavelength is ___________ related to frequency. |
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Definition
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Term
| How to calculate wavelength. |
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Definition
| c/f or 1.54 mm per us/frequency |
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Term
| The distance sound waves travel through a medium in one second. |
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Definition
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Term
| Propagation speed is fastest in _______, slowest in _____. |
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Definition
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Term
| The inability to be compressed. |
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Definition
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Term
| The relative weight of the volume of a material. |
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Definition
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Term
| Stiffness is ________ related to the speed of sound. |
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Definition
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Term
| Density is ________ related to the speed of sound. |
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Definition
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Term
| Weakening of sound as it travels through a medium. |
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Definition
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Term
| Common measurement for electrical signal strength and brightness of images. |
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Definition
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Term
|
Definition
3 2.00 -3 0.50
6 4.00 -6 0.25
9 8.00 -9 0.125
10 10.0 -10 0.10 |
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Term
| Two things that determine attenuation. |
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Definition
| path length and frequency |
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Term
| Distance and frequency are ________ related to attenuation. |
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Definition
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Term
| Three types of attenuation |
|
Definition
| absorption, reflection, and scattering |
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Term
| Type of reflection in which sound is reflected off a smooth boundary in one direction. |
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Definition
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Term
| Three parts of a sound beam when it encounters an interface. |
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Definition
| Incident, reflected, and transmitted |
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Term
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Definition
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Term
| When a wave reflects off an irregular surface and radiates in more than one direction. |
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Definition
| Diffuse (Backscatter) Reflection |
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Term
| Advantage of diffuse reflection. |
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Definition
| Suboptimal angles can produce reflections back to the transducer |
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Term
| Disadvantage of diffuse reflection. |
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Definition
| Lower strength than a specular reflector. |
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Term
| Images are best when the angle of incidence is __________ to the structure's surface. |
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Definition
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Term
| Type of scattering that occurs when the size of red blood cells are less than the wavelength. |
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Definition
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Term
| Redirection of sound in many directions. |
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Definition
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Term
The number of decibels of attenuation that occurs when sound wave travels one
centimeter |
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Definition
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Term
| Main form of attenuation in soft tissue. |
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Definition
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|
Term
| How to calculate attenuation coefficient in soft tissue. |
|
Definition
| dB = per MHZ x per cm x .5 |
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Term
The depth of tissue that results in 3dB
of attenuation. |
|
Definition
| Halve-Value Layer Thickness |
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|
Term
| The acoustic resistance to sound traveling in a medium. |
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Definition
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|
Term
| Reflected intensity + Transmitted intensity = ??? |
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Definition
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|
Term
| What is the impedance formula? |
|
Definition
| impedance = density x prop. speed |
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|
Term
| When transmission occurs at an obliques incidence and the wave becomes bent. |
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Definition
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|
Term
When the speed of medium 2 is GREATER
than the speed of medium 1 the
transmission angle will be _____ than
the incident angle. |
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Definition
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|
Term
| Time it takes for one pulse to occur. |
|
Definition
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|
Term
The distance or length a pulse
occupies in space from the start of
the pulse to the end of the same
pulse |
|
Definition
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|
Term
|
Definition
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|
Term
| A ______ SPL improves image resolution. |
|
Definition
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|
Term
| Pulse duration + one listening time |
|
Definition
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|
Term
| Number of pulses transmitted per second. |
|
Definition
| Pulse Repetition Frequency |
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|
Term
| Percentage of time that pulsed ultrasound is transmitting (not listening). |
|
Definition
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|
Term
| Time it takes from the pulse creation to the pulse reception. |
|
Definition
| Time of Flight or Go-Return Time |
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|
Term
| Time of flight is ______ related to depth. |
|
Definition
|
|
Term
| What is the 13 microsecond rule? |
|
Definition
| For every 13 microseconds of go-round time, the object is 1 cm deeper. |
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|
Term
| The property of a certain material to create a voltage when mechanically deformed. |
|
Definition
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|
Term
| The property of certain material to change shape when voltage is applied to them. |
|
Definition
| Reverse piezoelectric effect |
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|
Term
| Happens when the PZT material is heated above Curie temperature. |
|
Definition
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|
Term
| Temperature at which PZT is polarized, or 365 degrees Celsius. |
|
Definition
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|
Term
Located in front of crystal to insure
transmission of sound between crystal and skin. |
|
Definition
|
|
Term
| Impedance of the matching layer must be between the impedance of the ___ and ____. |
|
Definition
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|
Term
| The matching layer is equal to _____ of the wavelength. |
|
Definition
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|
Term
| Limits the ringing of the element. |
|
Definition
| Damping or backing material |
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|
Term
| A characteristic of frequency: homogenity or pureness of the sound beam. |
|
Definition
| Q-Factor (quality factor) |
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|
Term
| The _____ the q-factor, the better the image. |
|
Definition
|
|
Term
| The range or difference between the highest and the lowest frequencies in the pulse. |
|
Definition
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|
Term
| The lower the Q-Factor, the _____ the bandwidth. |
|
Definition
|
|
Term
| How to calculate Q-Factor. |
|
Definition
| main frequency / bandwidth |
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|
Term
| CW transducer frequency is determined by? |
|
Definition
| The frequency of the electrical signal. |
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|
Term
| PW transducer frequency is determined by? |
|
Definition
| Thickness and speed of sound of PZT |
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|
Term
| Speed of sound of PZT and frequency of sound are _______ related. |
|
Definition
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|
Term
| Thickness and frequency are _________ related. |
|
Definition
|
|
Term
| Relationship between PZT diameter and focal depth. |
|
Definition
|
|
Term
| Relationship between frequency and focal depth. |
|
Definition
|
|
Term
| Relationship between wavelength and focal depth. |
|
Definition
|
|
Term
Crystal diameter and beam divergence are _________ related in unfocused disc
shaped element |
|
Definition
|
|
Term
Frequency and beam divergence are
__________ related in unfocused disc
shaped element |
|
Definition
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|
Term
| A large active element may be thought of as millions of tiny, distinct, V-shaped sound sources (What principle is this?) |
|
Definition
|
|
Term
| Shape of a sound beam when wavelets interfere constructively? |
|
Definition
|
|
Term
| What happens to a sound beam when wavelets interfere destructively? |
|
Definition
|
|
Term
| Ability to distinctly identify 2 structures side by side or perpendicular to the beam |
|
Definition
|
|
Term
| What improves axial and lateral resolution? |
|
Definition
|
|
Term
| How does high frequency improve lateral resolution? |
|
Definition
| narrow beam and less divergence |
|
|
Term
Correct number of reflectors but at
improper depth |
|
Definition
|
|
Term
| Duplicate of true reflector (both real) and duplicate will be side by side at same depth |
|
Definition
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