Chapter 12 Flashcards
How many active elements are there in a mechanical transducer?
One active element
What is the advantage of using a 1.5 dimensional array?
Improve elevational resolution
What type is resolution is degraded by side lobes?
Lateral resolution
What is another name for slice thickness resolution?
Elevational resolution
Which transducer possesses the best slice thickness resolution?
1.5 dimensional array
What image is created with a 2-D array transducer?
3-D real-time image
Off axis sound beams created by a mechanical transducer is called what?
Side lobes
What term means adjustable focusing or multi focusing?
Phased array
What will lower the value of a ultrasound systems lateral resolution?
Use a curved PZT crystal
How many active elements are there in an annular array and what shape are they?
5 ring shaped active elements
What is another name for sequential array?
Switched array
When there is a damaged crystal in a linear sequential array and curvilinear sequential array what occurs in the image?
Vertical dropout
Which type of transducer results in horizontal dropout when there is a damaged crystal?
Annular phased array
What is used to get rid of grating lobes?
Apodization and Subdicing
What are grating lobes?
Off axis beams created by array transducers
