Samsung SONOACE R3 Manuel d'utilisateur télécharger pdf (Page 39)

Chapter 1 Safety

1-21

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 eciently and eectively.

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) and bone (TIb). 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 articially high or low thermal index readings e.g. presence of uid or bone,

or the ow 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.

Always limit ultrasound exposure time. Do not rush the exam. Ensure that the indices are kept to a

minimum and that exposure time is limited without compromising diagnostic sensitivity.

1 2 ... 34 35 36 37 38 39 40 41 42 43 44 ... 290 291

Pas de commentaire

Samsung SONOACE R3 Manuel d'utilisateur Page 39