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5.5.4
B/M mode
If you press the [B/M] button, a real-time B-mode image and a real-time M-mode image are displayed at the same time.
A scanning line appears in the B-mode image area, which indicates the active scanning position for the M image in the B
image area. You can change the position of the scanning line in the B image area using the trackball.
5.5.5
M mode
If you press the [M] button again, the B-mode image disappears; the M-mode image remains active on the entire screen.
The M-image mode represents the motion status of the tissue in the scan line. The image in M mode changes over time,
so it is mainly used for cardiac applications.
5.5.6
PW mode
The Doppler is used to obtain measurement data relating to the velocity of motile tissue and fluids. PW Doppler allows
you to selectively examine blood flow data from a small region called the sample volume.
The x-axis represents the time, while the y-axis represents the velocity – either forwards or backwards.
The PW Doppler is usually used to indicate the velocity, direction and spectral content of the blood flow of the selected
anatomical areas.
The PW Doppler can be combined with the B mode to quickly select the anatomical area for the PW Doppler examina-
tion. The location at which the PW Doppler data is acquired appears graphically on the B-mode image (sample volume
gate). The sample volume gate can be moved anywhere within the B-mode image.
PW mode examination procedure
Obtain a good B-mode image.
Press the
[PW]
button to display the sample volume cursor and gate.
Position the sample volume cursor by rotating the trackball left and right. Position or size the sample volume
gate by moving the trackball up and down, then press the
[ENTER]
button.
Press the
[UPDATE]
button to display the PW Doppler spectrum, and the system runs in combined B + Doppler
mode. The Doppler signal can be heard over the loudspeakers.
Optimise the PW Doppler spectrum as necessary.
Make sure that the sample line runs parallel to the blood flow.
Press the
[FREEZE]
button to keep the trace in the cine memory and exit the image display.
Perform measurements and calculations as required.
Log the results with your logging devices.
Press the
[FREEZE]
button to resume the image display.
Repeat the above procedure until all relevant yield loci have been investigated.
Insert the probe back into its corresponding holder.
When you use duplex mode for the first time, the Doppler spectrum is not activated. The Doppler sample volume ap-
pears in the default position and B-mode imaging or 2D mode is active. Moving the trackball changes the position of the
sample volume. Press the [Enter] key to toggle the trackball function between sample volume gate and size. Press the
[UPDATE] key after the sample volume gate has been defined to activate the spectral Doppler mode. Press the [UP-
DATE] key a second time to go back to 2D (B or colour), to update and deactivate the spectral Doppler.