55
➢
TIS: soft tissue thermal index applications, such as the abdomen and the heart
➢
TIB: the use of bone thermal index, such as the fetus (in late pregnancy),
focused on or close to the focus of the acoustic beam in the bone
➢
TIC: Skull thermal index applications such as pediatric and adult skulls.
WFUMB (World Federation of ultrasound in medicine and Biology) statement: 5 minutes
irradiation temperature rise of 4 degrees may cause potential harm to the embryo and fetal
tissue.
The smaller the MI/TI, the lower the biological effect
。
9.4.2
MI/TI display instructions
TI and MI display on the screen of centre. The operator should monitor these index values
in the inspection process, and to ensure that in the premise of effective diagnostic
information under the irradiation time and the output value is maintained at the lowest
possible level.
The TI and MI values are displayed at any operating conditions, and the step value is not
more than 0.2.
TI display items can be set in the prefab, open [the image preset parameter ]"B/THI" page,
you can see the acoustic output parameters preset, as shown below
：
Here you can set the level of TI display items and power levels.
Display accuracy is 0.1.
Be careful
If the MI or TI display values are greater than 1, please follow the
ALARA principle carefully
9.5
Sound power settings
Acoustical power adjustment
In the frozen state of the image, the ultrasonic energy is not output.
Default settings description
The operator is the most important factor to control the sound output.
The intensity level depends on the acoustic output in the scanning area. In the fetal
examination, be especially careful control of acoustic output intensity.
In this system, the user can preset the image parameters. Once the preset change default
settings for the original machine becomes invalid. Therefore, the user is responsible for the
default settings.
Default setting range
