Questions and Answers
Which of the following would be considered the narrowest part of the sound beam?
Which of the following is the part of the transducer that stops the ringing of the element?
Along with image depth, which of the following also determines the frame rate?
Number of lines per frame
Which type of resolution is an accurate representation of moving structures?
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Which of the following is the type of transducer that utilizes elements arranged in a concentric pattern?
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There are no moving parts in a mechanical transducer.
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Which of the following would be considered an advantage of a curved linear array over a phased array transducer?
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Along with crystal diameter, divergence in the far field is also determined by which of the following?
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Which of the following would cause a decrease in temporal resolution?
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Which of the following would cause an increase in frame rate?
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Which of the following is true about the diameter of the sound beam in the Fresnel zone?
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Which resolution is best in clinical imaging?
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Which of the following will increase the near zone length?
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Which of the following will decrease beam divergence in the far field?
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Imaging transducers have:
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Damping material produces all of the following except:
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Which of the following electrical patterns produces electronic focusing of the ultrasound beam?
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In an unfocused, single element transducer, the focal point of the sound beam measures how much of the total beam width?
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Which of the following facilitates the transmission of sound from the element into the patient's skin?
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Which of the following is the range of frequencies present within the beam?
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Which type of interference results in a larger sound wave?
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Which of the following transducers uses a motor for steering the beam?
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Which of the following best describes this component of the damping material?
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The elements are arranged in a ring in the linear sequenced array transducer.
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A larger aperture results in a shorter near zone length.
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Damping worsens axial resolution.
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Which of the following is not a synonym for axial resolution?
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Temporal resolution relates to which of the following?
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Which of the following may also be referred to as the far zone?
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What states that waves are the result of the interference of many wavelets produced at the face of the transducer?
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Which of the following is the resolution in the third dimension of the beam?
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Which of the following is true concerning the frequency and the near zone length?
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Which of the following is defined as changing the timing of the shocking of the elements in order to shape and steer the beam?
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Which of the following is not a component of spatial resolution?
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Which types of transducers are no longer used?
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Which of the following transducers is not used for imaging?
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Which of the following transducers is also referred to as a sector or vector transducer?
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Which of the following shortens the length of the pulse by decreasing the number of cycles in the pulse?
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Which of the following produces a pie-shaped image?
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The portion of the transducer that comes in contact with the patient is the
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What does heat sterilization do to an ultrasound transducer?
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Which of the following is defined as the minimum distance two reflectors can be, parallel to the beam, and still appear on the screen as two dots?
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Which of the following describes the result of destructive interference?
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To produce a transducer with a higher frequency one should:
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At the face of the transducer, the beam diameter is twice the size of the element thickness in unfocused single element transducers.
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Which of the following would be best utilized for imaging of deep structures in the abdomen?
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Which of the following is not a method of creating 3D images?
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Which of the following best describes the frame rate?
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Which of the following is represented as time, or the ability to display structures in real time?
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How are ultrasound transducers typically sterilized?
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Study Notes
Sound Beam and Transducer Concepts
- Focus is the narrowest part of the sound beam, critical for image clarity.
- Damping material in transducers prevents element ringing, enhancing image quality by blending pulses.
- Frame rate in ultrasound imaging is influenced by both image depth and the number of lines per frame, determining how smooth the image appears.
Resolution Types and Factors
- Temporal resolution relates to the accurate representation of moving structures, essential for dynamic imaging.
- Axial resolution is the best resolution for clinical imaging, allowing precise visualization of structures along the beam.
- Elevational resolution refers to the third dimension accuracy in imaging.
Transducer Types and Characteristics
- Annular array transducers feature elements arranged in concentric patterns, useful for certain imaging scenarios.
- Mechanical transducers utilize a motor for beam steering and may have moving parts, unlike other designs.
- Curved linear arrays offer advantages like a wide near field, making them suitable for various applications.
Beam Behavior and Crystal Properties
- Divergence in the far field of a sound beam is influenced by crystal diameter and frequency; larger crystals and higher frequencies reduce this divergence.
- The near zone length increases with larger crystal diameters and higher frequencies, improving image detail.
- Huygen's principle explains that wavelets at the transducer's face contribute to the overall sound waves generated.
Imaging Quality and Effects
- Increased line density may decrease temporal resolution but can increase frame rate, affecting image capture and display.
- Backing material shortens pulse length by reducing cycle count, contributing to better resolution and image quality.
- Heat sterilization is detrimental to ultrasound transducers, killing pathogens but also damaging the device.
Interference and Imaging Techniques
- Constructive interference leads to larger sound waves, enhancing image quality during ultrasonic examinations.
- Spatial resolution components exclude frame resolution, emphasizing detail in positioning and distance measurement.
- 3D imaging can be achieved through various techniques, but annular array transducers are obsolete for this purpose.
Miscellaneous Points
- Bandwidth refers to the range of frequencies within the ultrasound beam, affecting imaging fidelity.
- Matching layers enhance sound transmission from the transducer to skin, crucial for effective imaging.
- Cold-sterilization methods are preferred for ultrasound transducers to maintain functionality while ensuring safety.
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Description
Test your knowledge on key concepts from Chapter 2 of the Purple Book related to ultrasound physics. This quiz features essential terms and definitions that are crucial for understanding sound beam characteristics and transducer functions. Perfect for students studying medical imaging technology.