Terms Used In The Acoustic Output Tables - FujiFilm SonoSite M-Turbo User Manual

Terms used in the acoustic output tables

Table 44: Acoustic Output Terms and Definitions
Term
I
.3
SPTA
TI type
TI value
MI
I @MImax
pa.3
TIS
TIB
TIC
A
aprt
P
r.3
Wo
W (z )
.3 1
I (z )
SPTA.3 1
z
1
z
bp
z
sp
164
Definition
Derated spatial peak, temporal average intensity in units of milliwatts/cm
Applicable thermal index for the transducer, imaging mode, and exam type.
Thermal index value for the transducer, imaging mode, and exam type.
Mechanical index.
Derated pulse average intensity at the maximum MI in units of W/cm
(Soft tissue thermal index) is a thermal index related to soft tissues. TIS scan is
the soft tissue thermal index in an auto-scanning mode. TIS non-scan is the
soft tissue thermal index in the non-autoscanning mode.
(Bone thermal index) is a thermal index for applications in which the
ultrasound beam passes through soft tissue and a focal region is in the
immediate vicinity of bone. TIB non-scan is the bone thermal index in the
non-autoscanning mode.
(Cranial bone thermal index) is the thermal index for applications in which
the ultrasound beam passes through bone near the beam entrance into the
body.
Area of the active aperture measured in cm
Derated peak rarefactional pressure associated with the transmit pattern
giving rise to the value reported under MI (Megapascals).
Ultrasonic power, except for TIS
passing through a one centimeter window in units of milliwatts.
Derated ultrasonic power at axial distance z
Derated spatial-peak temporal-average intensity at axial distance z
(milliwatts per square centimeter).
Axial distance corresponding to the location of maximum [min(W
2
x 1 cm )], where z > zbp in centimeters.
 
A
1.69 in centimeters.
a p r t
For MI, the axial distance at which p
at which TIB is a global maximum (for example, z
2 .
, in which case it is the ultrasonic power
scan
in units of milliwatts.
1
is measured. For TIB, the axial distance
r.3
= z
sp b.3
2 .
2 .
1
(z), I (z)
.3 TA.3
) in centimeters.