SonoSite iLook, User Manual

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Chapter 8: References
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Chapter 8: References
This section includes information about clinical measurements that can be made with the system,
the accuracy of each measurement, and factors affecting measurement accuracy.
Display Size
The precision with which a caliper can be placed in an image can be improved by making sure the
area of interest fills as much of the screen as possible.
In 2D imaging, the distance measurement is improved by minimizing the display depth.
Caliper Placement
When making a measurement, accurate placement of the caliper is essential.
To improve caliper placement precision: adjust the display for maximum sharpness; use leading
edges (closest to the transducer) or borders for start and stop points; and maintain a consistent
transducer orientation for each type of measurement.
When the calipers are positioned farther apart, they get larger. When the calipers are moved closer
together, they get smaller. The caliper line disappears as the calipers get closer together.
2D Measurements
The measurements provided by the system do not define a specific physiological or anatomical
parameter. Rather, what is provided is a measurement of a physical property such as distance for
evaluation by the clinician. The accuracy values require that you can place the calipers over one
pixel. The values do not include acoustic anomalies of the body.
The 2D linear distance measurement results are displayed in centimeters with one place past the
decimal point, if the measurement is ten or greater; two places past the decimal point, if the
measurement is less than ten.
The linear distance measurement components have the accuracy and range shown in the following
table: