SPI Exam Pool Questions and answers. 100% Accurate, graded A+.

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SPI Exam Pool Questions and answers. 100% Accurate, graded A+. What is described as the ability of an object to resist compression and relates to the hardness of a medium? - ✔✔stiffness An i ... ncrease in PRF would lead to - ✔✔an increase in DF what has the higher propagation speed? air, bone, soft tissue or water - ✔✔bone what has a lower propagation speed? water, soft tissue, bone or lung tissue - ✔✔lung tissue as imaging depth increases, the PRF must - ✔✔decrease what law describes the amount of refraction that occurs at an interface? - ✔✔Snell's law pressure is typically expressed in - ✔✔pascals the typical range of frequency for diagnostic ultrasound imaging is - ✔✔1 to 20 MHz the attenuation coefficient in soft tissue is equal to - ✔✔one-half of the operating frequency micro denotes - ✔✔millionth what is described as the distance over which one cycle occurs - ✔✔wavelength what requires an oblique interface and a propagation speed mismatch - ✔✔refraction areas of high pressure and density are referred to as - ✔✔compressions spl can be calculated by - ✔✔multiplying the number of cycles by the wavelength density is typically measured in - ✔✔Kilograms per centimeter cubed as a sound wave travels through the human body, the intensity of the sound wave decreases as a result of - ✔✔attenuation what is the total attenuation that occurs if a 6 MHz sound beam travels through 4 cm of soft tissue - ✔✔12 dB, attenuation= f/2 * pL as imaging depth increases, PRP - ✔✔increases what are the units of df - ✔✔unitless the percentage of time that the ultrasound system is producing pulses of ultrasound describes the - ✔✔df density and propagation speed are - ✔✔inversely related what is determined by the sound source and medium - ✔✔wavelength what is defined as the number of ultrasound pulses emitted in 1 second - ✔✔prf what is defined as only the active time - ✔✔pd the intertia of the medium describes its - ✔✔density what is determined by the sound source only - ✔✔frequency if the angle of incidence is 40 degrees, what is the angle of transmission at the interface if medium 1 has a propagation speed of 1320 m/s and medium 2 has a propagation speed of 1700 m/s - ✔✔less than 40 degrees the change in the direction of the original sound wave that occurs when sound interacts with two different tissue types that have a different propagation speed is - ✔✔refraction which of the following is an appropriate unit of measurement for propagation speed - ✔✔millimeters per microsecond the major component of attenuation is: - ✔✔absorption in clinical imaging, the wavelength typically measures between - ✔✔.1 to .8 mm the df for cw ultrasound is - ✔✔100% what is the change in intensity if the power decreases by half - ✔✔intensity is halved damping of the sound beam - ✔✔reduces the spl adding damping to the transducer improves which type of resolution - ✔✔axial what time is defined as the beginning of one pulse to the beginning of the next pulse and, therefore, includes both the "on" and "off" time - ✔✔prp what are the units for pressure - ✔✔pascals or pounds per square inch what term is defines as "the power of a wave divided by the area over which the power is distributed" - ✔✔intensity transducers have material within them that, when electronically stimulated, produces ultrasound waves. This is most likely some form of: - ✔✔lead zirconate titanate what is the change in power if the amplitude triples - ✔✔it increases nine times the portion of the sound beam where the molecules are farther apart describes an area of - ✔✔rarefraction if only the density of a medium is increased, then the - ✔✔propagation speed will decrease sound is technically a - ✔✔mechanical and longitudinal wave the maximum value or minimum value of an acoustic variable minus the equilibrium value of that variable describes the - ✔✔amplitude what is the speed of sound in soft tissue - ✔✔1540 m/s what is considered the narrowest part of a sound beam - ✔✔focal zone what part of the transducer stops the ringing of the element - ✔✔damping material along with image depth, what also determines frame rate - ✔✔number of lines per frame which type of resolution is an accurate representation of moving structures - ✔✔temporal resolution if the depth is increased and the frame rate is unchanged, what must have decreased - ✔✔the number of lines per frame what transducer can be described as having the scan lines originate from a common point of origin - ✔✔sector array along with crystal diameter (aperture), what is the divergence in the far field also determined by - ✔✔frequency what would cause a decrease in temporal resolution - ✔✔increased line density what would cause an increase in frame rate - ✔✔increased PRF what is true of the diameter of the sound beam in the fresnel zone - ✔✔it decreases with distance from the transducer which resolution typically has the lowest number in clinical imaging - ✔✔longitudinal what would most likely increase the near-zone length - ✔✔large crystal diameter, high frequency what would most likely decrease beam divergence in the far field - ✔✔large crystal diameter, high frequency imaging transducers typically have - ✔✔low-quality factors, wide bandwidths what does damping material produce - ✔✔decreased sensitivity, wide bandwidths, low-quality factors what electrical pattern produces electronic focusing of the ultrasound beam - ✔✔curved in an unfocused, single-element transducer, the width at the focal point of the sound beam measures how much compared to the beam width at the fact of the transducer - ✔✔one-half what facilitates the transmission of sound from the element into the patient's skin - ✔✔matching layer what describes the range of frequencies present within the beam - ✔✔bandwidth which type of interference results in higher-amplitude sound waves - ✔✔constructive interference what affects temporal resolution - ✔✔line density, image depth, number of focal zones what are the components of the damping material - ✔✔epoxy resin loaded with tungsten what are synonyms for axial resolution - ✔✔range, depth, radial what does temporal resolution relate to - ✔✔frame rate what is referred to as the far zone - ✔✔fraunhofer zone what states that waves are the result of the interference of many wavelets produced at the face of the transducer - ✔✔Huygen's principle what is the resolution in the third dimension of the beam - ✔✔elevational what is the relationship between the frequency and the near zone - ✔✔the higher the frequency, the longer the near-zone length what is defined as changing the timing of the shocking elements in order to shape and steer the beam - ✔✔phasing what are the components of spatial resolution - ✔✔contrast, axial, elevational which transducer has no range resolution - ✔✔continuous-wave what transducer is not used for imaging - ✔✔continuous-wave what transducer is also referred to as a sector or vector transducer - ✔✔phased-array what shortens the length of the pulse by decreasing the number of cycles in the pulse - ✔✔backing material what produces a pie-shaped image - ✔✔phased arra [Show More]

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