Physics Chap 10 E.W

Question 1

What is “resolution” ?

Answer 1

An accurate image

Question 2

Axial resolution measures?

Answer 2

Structures that are parallel or “front to back” to the sound beams main axis

Question 3

A lower numerical value in axial resolution indicates?

Answer 3

Shorter pulses and improved image accuracy

Question 4

Axial resolution is related to which two measurements?

Answer 4

Spatial pulse length and Pulse duration

Question 5

Name the 4 synonyms for Axial resolution.

Answer 5

Longitudinal, Axial, Range, Radial, Depth- LARRD

Question 6

What unit is used to measure Axial resolution?

Answer 6

mm or any unit of distance

Question 7

T/F. Shorter pulses improve Axial resolution.

Answer 7

True

Question 8

Fewer cycles in a pulse is also called?

Answer 8

Less ringing

Question 9

T/F. Lower Frequencies have better axial resolution.

Answer 9

False. Higher frequencies have better axial resolution.

Question 10

T/F. If a transducer has more cycles in its pulse, it’s image accuracy will improve.

Answer 10

False. More cycles in a pulse degrades image accuracy.

Question 11

Which frequency has the best axial resolution?

Answer 11

High Frequency

Question 12

A longer pulse with more cycles will produce ______ ringing.

Answer 12

More ringing

Question 13

A shorter pulse with fewer cycles will produce _____ ringing

Answer 13

Less ringing

Question 14

Lateral resolution measures?

Answer 14

Structures that are perpendicular or “side by side” to the sound beams main axis

Question 15

What unit is lateral resolution measured in?

Answer 15

mm, cm, or any unit of distance

Question 16

Lateral resolution is determined by the _____ of the sound beam.

Answer 16

Width

Question 17

The 4 synonyms for lateral resolution are:

Answer 17

Lateral, Angular, Transverse, Azimuthal. LATA

Question 18

T/F. Narrower sound beams have better lateral resolution.

Answer 18

True

Question 19

What changes the accuracy of lateral resolution?

Answer 19

Depth and beam diameter

Question 20

T/F. The focal zone of the beam produces the best lateral resolution.

Answer 20

True

Question 21

What area of the beam produces the best lateral resoluion?

Answer 21

The focal zone

Question 22

T/F. The narrowest beam produces the best axial resolution.

Answer 22

False. The narrowest beam has the best lateral resolution

Question 23

Which is best for clinical imaging, axial or lateral resolution?

Answer 23

Axial resolution

Question 24

T/F. Lateral resolution and beam diameter are directly related.

Answer 24

True

Question 25

______ frequencies have the best range resolution.

Answer 25

High Frequencies

Question 26

The ability to distinguish two structures lying close together front-to-back is called _____.

Answer 26

Axial resolution- or - longitudinal, range, radial, depth resolution

Question 27

The ability to distinguish two structures lying close together side by side is called ______.

Answer 27

Lateral resolution- or angular, transverse, azimuthal resolution

Question 28

What does phased array mean?

Answer 28

Adjustable or multiple focusing

Question 29

Fixed focusing is also called ____ or ______ focusing.

Answer 29

Conventional or Mechanical focusing

Question 30

What are the two types of fixed focusing?

Answer 30

Internal and External focusing

Question 31

Which form of focusing uses a lens?

Answer 31

External focusing

Question 32

Which form of focusing does not use a lens?

Answer 32

Internal focusing. Instead it uses a curved PZT crystal

Question 33

Which of the two are the most common form of fixed focusing?

Answer 33

Internal focusing

Question 34

Define "focusing".

Answer 34

Concentrating sound energy into a narrower beam

Question 35

Which form of focus can be adjusted by the sonographer, external, internal, or phased array?

Answer 35

Phased array