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In 2D (B) mode imaging, the echo amplitudes are represented as brightness changes
on the image display screen. Since the ultrasound beam attenuates in tissue, the
degree of amplification required generally increases as depth increases. Regions of
high reflection are displayed as brighter, while regions of low reflection appear darker.
An M-mode image (cross-sectional image) can be displayed together with a 2D-mode
image on the same screen through time-sharing control, allowing the user to perform
M-mode diagnosis while observing a 2D-mode image.
In color Doppler imaging, phase detection is performed in a receive signal processing
circuit to obtain I and Q signals. These signals undergo frequency analysis with the
correlational method in a color Doppler imaging circuit to produce the mean velocity,
variance, and power information of the blood flow. These information items are
assigned color signals and represented as real-time two-dimensional color Doppler
images.
In Doppler imaging, the signals output from the receive signal processing board are
frequency-analyzed by fast Fourier transform (FFT) in a Doppler circuit to produce
velocity and power information. A Doppler image is then displayed, plotting velocity on
the vertical axis, time on the horizontal axis, and representing power as brightness.
This system supports basic measurements including distance, time, angle, and trace, as
well as combinations of some basic measurements. In addition, calculations based on
the measurement values can be performed for each region (circulatory organ, OB, etc.)
using widely accepted expressions. The calculation results can be displayed in values,
tables, or graphs.
No. 2B771-004EN*M
1-2
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