Description Of Voluson® 730Pro / Prov Operating Modes - GE Voluson 730Pro Service Manual

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EALTHCARE RETZTECHNIK
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IRECTION EVISION
5-2-1 Description of Voluson® 730Pro / ProV Operating Modes
5-2-1-1 B-Mode or 2D-Mode
B-Mode or 2D-mode is a two-dimensional image of the amplitude of the echo signal. It is used for
location and measurement of anatomical structures and for spatial orientation during operation of other
modes. In 2D-mode, a two-dimensional cross-section of a three-dimensional soft tissue structure such
as the heart is displayed in real time. Ultrasound echoes of different intensities are mapped to different
gray scale or color values in the display. The outline of the 2D cross-section may be a rectangle,
parallelogram, sector or 360-degree circle, depending on the particular transducer used. 2D-mode can
be used in combination with any other mode.
5-2-1-1-1 Tissue Harmonic Imaging (THI) incl. Coded Harmonics
In Tissue Harmonic Imaging, acoustic aberrations due to tissue are minimized by receiving and
processing the second harmonic signal that is generated within the insonified tissue. Voluson® 730Pro
/ ProV`s high performance THI provides superb detail resolution and penetration, outstanding contrast
resolution, excellent acoustic clutter rejection and an easy to operate user interface for switching into
THI mode. Coded Harmonics enhances near field resolution for improved small parts imaging as well
as far field penetration. It diminishes low frequency amplitude noise and improves imaging technically
difficult patients. It may be especially beneficial when imaging isoechoic lesions in shallow-depth
anatomy in the breast, liver and hard-to-visualize fetal anatomy.
Coded Harmonics may improve the B-Mode image quality without introducing a contrast agent.
5-2-1-2 M-Mode
In M-mode, soft tissue structure is presented as scrolling display, with depth on the Y-axis and time on
the X-axis. It is used primarily for cardiac measurements such as value timing on septal wall thickness
when accurate timing information is required. M-mode is also known as T-M mode or time-motion mode.
Ultrasound echoes of different intensities are mapped to different gray scale values in the display.
M-mode displays time motion information of the ultrasound data derived from a stationary beam.
Depth is arranged along the vertical axis with time along the horizontal axis. M-mode is normally used
in conjunction with a 2D image for spatial reference. The 2D image has a graphical line (M-line)
superimposed on the 2D image indicating where the M-mode beam is located.
5-2-1-3 Color Doppler Mode
Color Doppler is used to detect motion presented as a two-dimensional display.
There are three applications of this technique:
• Color Flow Mode (C) - used to visualize blood flow velocity and direction
• Power Doppler (PD) - used to visualize the spatial distribution of blood
• Tissue Doppler (TD) - used to visualize tissue motion direction and velocity
5-2-1-3-1 Color Flow Mode
A real-time two-dimensional cross-section image of blood flow is displayed. The 2D cross-section may
be presented as a rectangle, parallelogram, trapezoid, sector, or a full circle, depending on the
particular transducer used. The 2D cross-section is presented as a full color display, with various colors
being used to represent blood flow (velocity, variance, power and/or direction). Often, to provide spatial
orientation, the full color blood flow cross-section is overlaid on top of the grayscale cross-section of soft
tissue structure (2D echo). For each pixel in the overlay, the decision of whether to display color
(Doppler), gray scale (echo) information or a blended combination is based on the relative strength of
return echoes from the soft tissue structures and from the red blood cells. Blood velocity is the primary
parameter used to determine the display colors, but power and variance may also used. A high pass
filter (wall filter) is used to remove the signals from stationary or slowly moving structures. Tissue motion
is discriminated from blood flow by assuming that blood is moving faster than the surrounding tissue,
although additional parameters may also be used to enhance the discrimination. Color flow can be used
in combination with 2D and Spectral Doppler modes.
5-6
DRAFT (A 28, 2008)
PRIL
Section 5-2 - General Information
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