Ch. 12: 2D Imaging

Disc shaped crystals improve _______ resolution and rectangular shaped active elements improve _______ resolution.

• Axial; lateral

• Temporal; elevational

• Lateral; temporal

• Elevational; lateral

How many active elements are in a mechanical transducer?

• 2

• 5

• 1

• 10

Apodization resolves which artifact(s)?

• ONLY reduces grating lobes

• ONLY minimizes side lobes

• Minimizes side AND grating lobes

• Doesn't deal with these artifacts

A mechanical beam can be focused:

• Externally

• Internally

• By the sonographer

• Can't be focused

To achieve a narrow focus, the beam's spike pattern must be:

• Straight

• Angled

• D-shaped

• Curved

Grating lobes are created by:

• Array transducers

• Single element transducers

• Both array and single element transducers

Focusing occurs:

• During transmission

• During reception

• During transmission and reception

Annular phased arrays are steered:

• Electrically

• Mechanically

• Manually

• By the sonographer

Side lobes are created by:

• Array transducers

• Single element transducers

• Both array and single element transducers

A damaged annular phased PZT would lead to:

• Inconsistent or erratic beam steering and focusing

• Vertical dropout

• Horizontal dropout

• Loss of entire image