Term
| what is another name for Fresnel Zone? |
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Definition
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Term
| in ultrasound imaging, what is the most common piezoelectric material used? |
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Definition
| Lead zirconate Titanate or PZT |
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Term
| what are the results when damping materials is added to thge transducer? |
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Definition
reduce ringing of the pulse
-decreases SPL, PD
-increases wide bandwidth
-improves axial resolution |
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Term
| which materials are naturally piezoelectric? |
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Definition
quartz amber
tourmaline glucose
rochell |
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Term
| what will happen to the near zone length if the transducer's frequency is changed from 5.0 MHz to 10.0 MHz |
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Definition
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Term
| which type of transducer are grating lobes associated with? |
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Definition
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Term
| what is electronic curvature? |
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Definition
| "firing patterns that focus beam" |
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Term
| should the sonographer use high or lower frequency transducer to obtain improved spatial resolution? |
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Definition
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Term
| what is the name of the transducer which has collection of ringed elements with a common center? |
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Definition
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Term
| True or False : many active elements are fired almost at the same time with Phased Arrray Transducer? |
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Definition
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Term
| what is the name of the principle which states thaT each tiny part of the transducer face may be considered a separate and individual sound source? |
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Definition
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Term
| what would be the most acceptable choice for the matching layer when the impedance of the transducer's piezoelectric element is 1,800,000 rayls and the impedance of the skin is 1,4000,000 Rayls? |
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Definition
pzt > matching layer > gel > skin
find a number in between |
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Term
| what is th eterm used when the firing pattern of an Arraty transducer steers the beam up or down\? |
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Definition
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Term
| what is the purpose of using coupling gel to scan? |
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Definition
gel furthers the % of sound transmitted into and out of the body
- transmission(AKA) main BANG at the skin surface |
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Term
| what does the indirect pieozoelectric effect sound? |
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Definition
| turns electrical energy into acoustic energy. |
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Term
| which transducer has the focus that is preset at a fixed point? |
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Definition
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Term
| A convex sequential Array Transducer will have what type of image format? |
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Definition
Blunted Sector shaped
-rockettop |
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Term
| in which scenario wouls multiple focal zones be advised? |
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Definition
Superficial structures
-(small parts) |
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Term
| An Annular transducer that has element damage will appear which way on the ultrasound display? |
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Definition
| horizontal band of dropout |
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Term
| when a liner switched Array transducer has one of the element damgae, how will this affect the ultrasound image on the display |
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Definition
| band of dropout extending from th etop to the bottom of the image |
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Term
| which term refer to Axial Resolution? |
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Definition
longitudinal, Range , Radial Depth
L.A.R.R.D |
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Term
| what should you increase to increase the Near Zone length? |
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Definition
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Term
| what is the Axial Resolution equal to? |
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Definition
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Term
| How is the US beam Steered with an Annular Arry Transducer? |
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Definition
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Term
| how do you calculate the quality factor mathematically? |
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Definition
Q-factor = Main frequnecy
bandwidth |
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Term
| what is it called when some types of material are mechanically deformed and create a voltage? |
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Definition
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Term
| what is lateral Resolution LEAST influnced by? |
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Definition
| (Damping) backing material |
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Term
| what is the best choice in regard to the thickness of the matching layer(s)? |
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Definition
1/4
a quarter of a wavelength |
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Term
| which array transducer steers the beam Mechanically? |
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Definition
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Term
| with a 3.5 MHz Transducer will the Piezoelectric element be thicker or thinner than 7.5 MHz transducer? |
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Definition
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Term
| what two changes will affect Axial Resolution the most? |
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Definition
-high Frequency
-pulse damping |
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Term
| A decrease in pulse duration will result in _______ frequency bandwidth |
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Definition
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Term
| what is lateral Resolution equal to? |
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Definition
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Term
| True or False: in a mechanical scanner there are many active elements which are firing at almost the same time. |
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Definition
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Term
| what is the name of the material that is plaved behined the rear face of the transducer which reduces pulse duration? |
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Definition
(backing material)
damping |
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Term
| what is another name for Lateral Resoultion? |
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Definition
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Term
| what statement would best describe the focal point? |
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Definition
| where beam diameter is the narrowest |
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Term
| An acoustic lens in front of the piezoelectric crystal is a type of ________ beam focing |
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Definition
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Term
| ultrasound intensity will vary the nost in which Zone? |
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Definition
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