Mindray ZONARE z.one pro Instructions For Use Manual page 90

5. Press the <Select> key to start an ARFI acquisition. The ARFI Velocity result window will
display on the image area.
The stiffness is converted into a velocity value by the formula:
ARFI velocity
The measurement accuracy of the ARFI velocity is about 50%, and the measure repeatability
of the ARFI velocity is about 20%

Measurement Bias Information Table
The Measurement Bias Information table display the bias and precision of the ARFI
measurement as a function of the object stiffness (Bias/Precision vs. Object Stiffness) and depth
(Bias/Precision vs. Depth) for the C4-1 probe.
Stiffness (kPa)
4
12
25
48
Depth (cm)
4.0
5.0
6.0
7.0
Note:
ROI size is fixed to 10mm and not adjustable.
1.
The data in the above tables are gained from measurement on elastomer phantom CIRS
2.
039.
z.one pro Instructions
stiffness
√
=
2
3*ρ
Bias/Precision vs Stiffness, depth = 5.0 cm
Bias, kPa
5.32 (33%)
16.7 (39%)
32.5 (30%)
60 (25%)
Bias/Precision vs Depth, stiffness = 25 kPa
Bias, kPa
31.0 (24%)
31.3 (25%)
31.8 (27%)
31.5 (26%)
, ρ = 1.03.
Precision (std), kPa
0.40 (10%)
0.36 (3%)
2.25 (9%)
1.92 (4%)
Precision (std), kPa
3.1 (10%)
3.1 (10%)
3.1 (10%)
3.1 (10%)
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