Download SPI Ultrasound Physics Finals Study Guide.pdf and more Exams Nursing in PDF only on Docsity!
SPI Ultrasound Physics Finals Study
Guide
What do waves transfer from one location to another? - โ Energy Which of the following best describes sound waves? - โ Longitudinal, Mechanical wave As sound travels through a medium, what term best describes the effects of the medium on the sound wave? - โ Acoustic Propagation Properties Describe the term "Compression" - โ Squeezed Together Describe the term "Rarefraction" - โ Stretched Apart Name the 7 parameters that describe sound waves - โ Period Frequency Amplitude Power Intensity Wavelength Propagation Speed What is the horizontal axis of a graph called? - โ X-axis How many nanoseconds are in 9 seconds? - โ 9,000,000, Which of the following is not a measure of area? - โ Cubic Meters
List these metric terms in increasing order: - โ Micro Milli Deci Deca Hecto Mega All of the following are measures of length except: - โ Second Pair of waves are in phase, what occurs when these waves interfere? - โ Constructive Interference Sound can be characterized as: - โ Cyclical oscillation in certain variables Sound is best described as - โ A series of compressions and rarefraction Which of the following are considered acoustic parameters? - โ Frequency Period Sound must propagate through a - โ medium Name the 3 acoustic variables - โ Pressure Density Distance What are the units of "Pressure" - โ Pa How are the height of a person and the color of their automobile related? - โ Unrelated How much bigger is a billion than a million? -
The pulse repetition frequency (PRF) is the - โ Reciprocal of pulse repetition period (PRP) What is the pulse duration equals to? - โ Period multiplied by the number of cycles in the pulse If all the factors remain unchanged, what happens to the duty factor, when the pulse repetition frequency increases? - โ Increases What happens to the pulse duration when a sonographer decreases the maximum imaging depth in an ultrasound scan? - โ Remains the same In diagnostic imaging, what establishes the pulse repetition frequency? - โ The source of the sound What are the units of pulse repetition frequency (PRF)? - โ 1 /seconds Using a specific transducer, what happens to the spatial pulse length as the sonographer increases the maximum imaging depth? - โ Remains the same Which of the following terms does NOT belong with the others - โ Shallow Imaging While using the same ultrasound machine and transducer, which of the following can a sonographer alter? - โ Pulse repetition period (PRP) Pulse repetition frequency (PRF) Duty Factor A sonographer adjusts the maximum depth of an ultrasound system. Which of the following also changes? - โ PRF & PRP
If all other factors remain unchanged, what happens to the duty factor when imaging depth increases? - โ Decreases A sonographer adjusts the depth of view of an ultrasound scan from 8 cm to 16 cm. Would each of the following parameters change? Period PRF Duty Factor PRP - โ Period = Remains the same PRF = Decrease Duty Factor = Decrease PRP = Increase What determines the pulse duration? - โ Source of the wave What event does Snell's law govern? - โ Refraction An ultrasound wave strikes an interface between two media at a 90 degree angle. The propagation speeds of the media are identical. However, the densities of the media are different. Which is true? - โ Reflection will definitely occur What are the units of the intensity reflection coefficient? - โ None Acoustic impedance is a property of the _______ and has the units of _______ - โ Medium, Rayls (Z) Increasing output power is the most common way to improve (increase) the signal-to- noise ratio. - โ True These five operations of the receiver must be performed in the appropriate order for the system to function properly, please rank them: - โ Amplification
The _______, of an analog scan convert is excellent because of the large number of storage elements within the matrix - โ Spatial resolution The dynamic range of a system: - โ Is the ratio, between the largest and smallest signals which is accurately measured Gray scale systems typically use _______ as a means of signal dynamic range reduction. - โ Compression Which of this statements regarding a bit of computer memory is false? - โ It is a smallest element of an image Is the following a form of information usually digital or analog? The signal from the transducer to the receiver _______ - โ Analog An uncompressed signal has a dynamic range of 90 dB. the signal undergoes 30 dB of compression. What is the dynamic range of the compression signal? - โ 60 dB (Subtract) Which of the following statements regarding a pixel is false? - โ It displays up to 3 gray shades simultaneously The acronym TGC denotes - โ Time Gain Compensation Which of the following is not true about spatial compounding? - โ Can be performed with a mechanical transducer Demodulation is a process of: -
โ Changing an electrical signal's form Which of these components typically has the lowest dynamic range? - โ Display All of the following are consistent with an image containing only black and white and no other shades of gray except: - โ Wide dynamic range The process of demodulation incorporates which of the following tasks? - โ Enveloping Rectification What is the primary disadvantage of video tape and computer this methods of image archiving? - โ The information is vulnerable to erasure when exposed to strong magnetic field Why are sonographic images usually compressed before sending to PACS? - โ Reduce the time to transmit the image Dynamic frequency tuning uses only _______ frequency reflections to create the superficial portion of the image and _______ frequency signals are used to create deeper portions of the image. - โ High Lower Where does code excitation takes place? - โ In the pulser With frequency compounding, how many pulses are transmitted down each scan line? - โ 1 Which of the following technologies uses long sound pulses to create an image? - โ Code excitation In modern Elastography, how are the tissues deformed? - โ Automatically Which of these is binary number? -
โ Three dimensional real time image Which of the following forms of focusing is different from the others? - โ Dynamic receive True or False? The curved pattern of delays in the electrical spikes used in a phased array transducer focuses the beam during reception. - โ False All of the following describe dynamic receive focusing EXCEPT - โ may be used by single crystal transducers How are the PZT crystals excited when using an ultrasound system with linear sequential array transducers? - โ In a specific order Which of the following is best described as mechanically steered and multi-focus? - โ Annular phased array transducer Which imaging modality places dots of dissimilar gray scale on the display? - โ B-mode Which transducer possesses the best slice thickness resolution? - โ 1 1/2 dimensional arrays A linear sequential array transducer has 128 crystals. How many crystals are fired to create a single sound beam? - โ A small group True or False, As frame rate increase, the image quality may degrade. - โ True A sonographer, using a phased array ultrasound system, turns off the multi-focus feature. What is the most likely consequence of this action? - โ The temporal resolution improves A sonographer adjusts an ultrasound machine to double the depth of view from 5 cm to 10 cm. If the frame rate remains the same, which one of the following also changed? - โ Narrower Sector
Which of the following is consistent with increased or improved temporal resolution? - โ Higher frame rate A sonographer increases the line density from 1 line per degree of sector to 3 lines per degree of sector. What is the consequence of this action? - โ The temporal resolution decrease What is the primary advantage of multiple focal zones along each scan line of a two dimensional image? - โ Improved lateral resolution A sonographer changes an image's sector size from 90 to 45 degree. The frame rate remained unchanged. What else must have happened? - โ The line density was doubled
