Ultrasound Physics Exam 1

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The frequency of a transducer does not change. If the diameter of the new piezoelectric crystal increase, what happens happens to the near zone length?

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The frequency of a transducer does not change. If the diameter of the new piezoelectric crystal increases, what happens to the beam diameter in the far zone?

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The frequency of a transducer does not change. If the diameter of the new piezoelectric crystals increases, what happens to wavelength?

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The frequency of a transducer does not change. If the diameter of the new piezoelectric crystal increase, what happens to the beam diameter in the near zone?

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At the location is the sound beam diameter three time greater than the transducer diameter?

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What is the shape of a sound beam created by a tiny piece of PZT?

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Which of the following explains why a sound beam created by a disc-shaped crystal is hourglass-shaped?

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Which of the following locations is the deepest?

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Which of the following locations is the most shallow?

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A pair of 6MHz probes are identical excepts for the active element diameter. The active element diameters are 6mm and 10mm. The sound beam of which probe will have a shallower focus?

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A pair of 9mm diameter probes are identical except for frequency, which is 3MHZ and 6MHz. WHich beam will have shallower focus?

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Which of the following probes creates a beam with the deepest focus?

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Which of the following probes creates a beam with the shallowest focus?

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Which of the following probes creates a beam with a the shallowest focus?

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Active elements diameter and near zone are directly related?

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Transducer frequency and near zone length are inversely related.

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Wavelength and near zone length are inversely related.

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A pair of 6 MHz probes are identical excepts for the active element diameter, which is 6 mm and 10 mm. Which beam will be more compact in the far field?

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A pair of 9 mm diameter probes are identical except for frequncies, which are 3 MHz and 6MHz. Which sound beam will spread out more in the far field>

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Which of the following probes creates a beam with least divergence?

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Which of the following probes creates a beam with most divergence?

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Which of the following probes create a beam with the most divergence?

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Transducer frequency and beam divergence are inversely related

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Active element diameter and beam divergence are inversely related.

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Mechanical scanning and linear phased arrays create sector-shaped images

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Many active elements fire at almost the same time in mechanical scanner.

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Many active elements fire at almost the same time in a phased array scanner.

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Which of the following transducers is best described as mechanically steered and fixed, single focused?

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Which of the following is best described as mechanically steered and multi-focus?

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Which of the following transducers creates a rectangular shaped image?

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A linear phased array transducer has 128 crystals. How many of these crystals are fired to create a single sound beam?

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A linear sequential array transducer has 128 crystals. How many of these crystals are fired to create a single sound beam?

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In a linear phased array, what is the firing patten that steers a beam to the left or right?

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In linear phased arrays, what is the firing pattern that focuses a sound beam?

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There are large time delays in the firing pattern of a linear phased array transducer.

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A machine that displays A-mode and Two- dimensional image is called a duplex scanner.

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A machine that displays a Doppler and two-dimensional images is called a duplex scanner.

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Which of the following improves elevational resoultion?

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Side lobes degrade axial resolution

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Side lobes degrade lateral resolution

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Which of the following forms of resolution improve when frame rate increases?

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Which of the following is consistent with improved temporal resolution?

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All of the following decrease temporal resolution except?

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A sonographer adjusts an ultrasound scan to double the depth of view from 5 cm to 10 cm. What happens to the frame rate?

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A sonographer adjusts an ultrasound scan to double the depth of view fro 5 cm to 10 cm. If the frame rate remains the same which on of the following also occurs?

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A sonographer adjusts an ultrasound machine to change the sector siz for 90 to 45 degrees. Nothing else changes. What happends to the frame rate?

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A sonographer adjusts an ultrasound system to change the sector size for 90 to 45 degree. The frame rate was unchanged. What else must have happened?

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A sonographer using a phased array ultrasound system turns off the multi-focus feature. What is the most likely consequence of this action?

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A sonographer increases the line density from 1 line per degree of the sector to 3 lines per degree of the sector. What is the most likely consequence of this action?

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A sonographer reduces the sector angle for 90 degrees to 30 degrees. At the same time, the ultrasound system automatically increases the lines density from 1 line per degree to 2 lines per degree. No other change is made. What will happen to the frame rate?

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A sonographer reduces the sector angle for 90 degrees to 30 degrees. At the same time, the ultrasound system automatically increases the lines density from 1 line per degree to 3 lines per degree. No other change are made. What will happen to temporal resolution?

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Which of the following is most important in determinging the frame rate of a system?

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Which of the following is most important in determining frame rate of a system?

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What is the frame rate if each image of the ultrasound system is created in 0.02 sec (1/50 sec)

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What is the time needed to make a single image if the frame rate of an ultrasound system is 20 Hz?

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The critical factor in determining frame rate, line density, and imaging depth is the tranducer style.

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The number of lines per frame and the frame rate determine the frequency

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The number of lines per frame and frame rate determine the PRF

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If the imaging depth of a scan is 15 cm and there are 100 lines in the image, then the number of pulses making up the scan is 1500.

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If the imaging depth of a scan is 15 cm and there are 100 lines in the image, then the number of pulses making up the scan is 100.

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If 100 scan lines make up an image and the frame rate is 30 per second, then the transducer's frequency is 3,000 HZ

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If 100 scan lines make up an image and the frame rate is 30 per second, then the system's PRF is 3,000 Hz

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When the frame is 30Hz, how long does it take to create a frame?

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Under certain conditions, an ultrasound system creates imagine in 0.01 seconds. What is the frame rate?

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What is the fundamental limitation of temporal resolution?

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All of the following are components of an ultrasound system except?

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This type of pulser generates a constant electrical signal in the form of a sine wave

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This type of pulser generates a single electrical spike, which ultimately creates a single sound pulse.

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This type of pulser generates numerous electrical spikes, which ultimately create a single sound pulse

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