Pregunta 1
Pregunta
What is the term for an area of the image where there is no returning echoes (black)
Respuesta
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hypoechoic
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anechoic
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echogenic
Pregunta 2
Pregunta
What are the advantages of ultrasound?
Respuesta
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Good soft tissue information, real time, no ionising radiation and accurate measure of structures
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Can carry out blood studies, relatively quick and cost effective, highly operator dependant, image interpretation
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Can carry out blood studies, ionising radiation, real time and accurate measure of structures
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Highly operator dependant, accurate measure of structures, image interpretation, highly operator dependant
Pregunta 3
Pregunta
True or False. The frequency of ultrasound is below the human hearing?
Pregunta 4
Pregunta
What frequency range is used for ultrasound?
Respuesta
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20-20,000Hz
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1-20MHz
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20-40MHz
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1-20Hz
Pregunta 5
Pregunta
What are the four basic components of ultrasound equipment?
Respuesta
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Transducer, monitor for display, housing with electronics and controls, coupling gel
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Transducer, timing device, housing with electronics and controls, recording device
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Transducer, monitor for display, housing with electronics and controls, recording device
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Transducer, timing device, housing with electronics and controls, coupling gel
Pregunta 6
Pregunta
When was the piezoelectric effect discovered by Jacques and Pierre Curie?
Pregunta 7
Pregunta
Name the two basic waves by which energy can be transmitted from one point to another
Pregunta 8
Pregunta
True or False? Light and X-rays are electromagnetic waves
Pregunta 9
Pregunta
What are mechanical waves described as?
Respuesta
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propagation of energy through a medium by cyclic pressure variations
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distinguished by energy, frequency and wavelength
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Man-made forces changing the frequency of the wave
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similar to ocean waves
Pregunta 10
Pregunta
Which of the following deformable elastic mediums can be used for propagation?
Respuesta
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Air
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Water
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Soft tissue
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All of the above
Pregunta 11
Pregunta
What is the frequency of a wave?
Respuesta
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The difference between maximum value and equilibrium value
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Length of one cycle
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The number of cycles that occur per second
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The speed of the soundwave as it passes through the tissue
Pregunta 12
Pregunta
True or false? With heavier molecules the sound transmits with faster velocity
Pregunta 13
Pregunta
True or False? With more compressable materials (eg air) the sound transmits at a lower velocity
Pregunta 14
Pregunta
What part of the beam affects the strength of the echo?
Respuesta
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intensity
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transducer
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shadowing
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placement
Pregunta 15
Pregunta
What is the change in direction of an ultrasound beam when it crosses a boundary at an angle?
Respuesta
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Rarefraction
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Attenuation
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Beam angling
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Focusing
Pregunta 16
Pregunta
What do the attenuation processes include?
Respuesta
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absorption
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Divergence
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Scattering
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Reflection
Pregunta 17
Pregunta
Which of the following has the lowest attenuation coefficient?
Respuesta
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Blood
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Lung
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Soft Tissue
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Brain
Pregunta 18
Respuesta
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Is a result of internal friction forces
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Is when ultrasound energy is converted into heat
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Is the change of direction the beam takes when passing through different structures
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Directly removes energy from the beam
Pregunta 19
Pregunta
True or false? Beam divergence cannot occur after refraction of a curved surface
Pregunta 20
Pregunta
What is Rayleigh scattering?
Respuesta
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When the interface the beam hits is
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When the interface the beam hits is >1 wavelength, scattering occurs equally in two directions
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When the interface the beam hits is >1 wavelength, scattering occurs equally in all directions
Pregunta 21
Pregunta
Why is scatter a disadvantage?
Respuesta
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only a small portion of the beam returns to the transducer
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It creates radiation dose to the patient
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scattered waves interact with each other to form back scatter patterns
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Mentally affects the operator
Pregunta 22
Pregunta
Which kind of reflection occurs when a soundwave strikes a large smooth surface?
Respuesta
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non-specular
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diffuse
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specular
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acoustic
Pregunta 23
Pregunta
What is acoustic impedance a product of?
Respuesta
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the material's density and velocity of ultrasound in the material
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the ultrasound's density and the velocity of the material
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the weight of the transducer and the velocity of ultrasound in the material
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the interface beam angle and the material density
Pregunta 24
Pregunta
True or False? Far gain is the amount of gain applied to the distant echoes