Knobology

Question 1

On switch

Answer 1

Give ultrasound system access to electricity which excites the piezoelectric crystal in the connected transducer.

Question 2

Piezoelectric crystals

Answer 2

Emit soundwaves as a result to their exposur3 to electricity.

Question 3

Preset

Answer 3

Allows operator to select the type of examination which activates the pre-defined factory settings for the specific examination. Includes the transducer frequency, acoustic output power, overall gain, dynamic range, depth

Question 4

Frequency

Answer 4

High frequency soundwaves emitted and determined by the thickness of the piezoelectric crystalsband the damping material behind them. Damping material used to shorten the pulse emitted.

Question 5

Output power

Answer 5

Alara principle kept in mind but not to the expense of image quality. Find balance of minimum opp and image quality to reduce risk of biological effects. Over all gain is safer

Question 6

Overall gain

Answer 6

Image quality improved by adjusting the brightness of the entire field without increasing intensity. Achieved by amplifying echo signals returning from the body.

Question 7

Time gain compensation

Answer 7

Some structures are more affected by attenuation and therefore need additional compensation for loss of sound energy.
A set of depth specific slide controls that can be used for echo-signak amplification at different depths. Allows adjustment to echo signals in near field, mid field and far field to improve axial resolution

Question 8

Depth

Answer 8

Adjusts the distance of field of view

Question 9

Zoom

Answer 9

Magnifying the field of interest.
Read zoom relies on stored images which enlarge the pixels density.
Write zoom maintain pixel density by zooming image live

Question 10

Focal zone

Answer 10

Improves lateral resolution in a region of interest. Minimize effect of attenuation.

Question 11

Lateral resolution

Answer 11

The ability to identify structure lying side by side as separate structures.

Question 12

Axial resolution

Answer 12

The ability to identify a structure lying on another structure as separate structures.

Question 13

Freeze/cineloop

Answer 13

Enables operator to stop and evaluate the image quality before storage.
Cineloop, select best image of frozen image format last few seconds prior freezing.

Question 14

THI Tissue harmonic imaging

Answer 14

Improves image quality by eliminating weak echoes that can,oud the image when the fundamental frequency of the transducer is used.

Question 15

Dynamic range

Answer 15

Determine the range of shades of gray to be displayed on the monitor.
Broad shades of gray displays a wider range of echo-intensity between bright and dark and
produces a smoother image overall.
narrow shades of gray displays a narrower range
of echo-intensity between bright and dark and produces a higher contrast between two
regions of different echogenicity