Samsung ACCUVIX XG Instrukcja Użytkownika Pobierz pdf (Strona 44)

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Operation Manual

output, is that receiver controls should be optimized before increasing output. For example; before

increasing output, optimize gain to improve image quality.

Additional Considerations

Ensure that scanning time is kept to a minimum, and ensure that only medically required scanning is

performed. Never compromise quality by rushing through an exam. A poor exam will require a follow-

up, which ultimately increases the time. Diagnostic ultrasound is an important tool in medicine, and,

like any tool, should be used efficiently and effectively.

Output Display Features

The system output display comprises two basic indices: a mechanical index and a thermal index. The

thermal index consists of the following indices: soft tissue (TIs), bone (TIb) and cranial bone (TIc). One

of these three thermal indices will be displayed at all times. Which one depends upon the system

preset or user choice, depending upon the application at hand.

The mechanical index is continuously displayed over the range of 0.0 to 1.9, in increments of 0.1.

The thermal index consists of the three indices, and only one of these is displayed at any one time.

Each probe application has a default selection that is appropriate for that combination. The TIb or TIs is

continuously displayed over the range of 0.0 to maximum output, based on the probe and application,

in increments of 0.1.

The application-specific nature of the default setting is also an important factor of index behavior. A

default setting is a system control state which is preset by the manufacturer or the operator. The system

has default index settings for the probe application. The default settings are invoked automatically by

the ultrasound system when power is turned on, new patient data is entered into the system database,

or a change in application takes place.

The decision as to which of the three thermal indices to display should be based on the following

criteria:

Appropriate index for the application: TIs is used for imaging soft tissue; and TIb for a focus at or near

bone. Some factors might create artificially high or low thermal index readings e.g. presence of fluid

or bone, or the flow of blood. A highly attenuating tissue path, for example, will cause the potential for

local zone heating to be less than the thermal index displays.

Scanned modes versus unscanned modes of operation affect the thermal index. For scanned modes,

heating tends to be near the surface; for unscanned modes, the potential for heating tends to be

deeper in the focal zone.

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Samsung ACCUVIX XG Instrukcja Użytkownika Strona 44