Color Flow Doppler Mode - GE LOGIQ E9 Service Manual

GE
D 5573152-100, R
IRECTION
5-2-6 LOGIQ E9's Operating Modes
5-2-6-1 B-Mode
B-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 B-
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 (B-Mode) (B-Mode) cross-section is a sector,
depending on the particular transducer used. B-mode can be used in combination with any other mode.
5-2-6-1-1 Harmonic Imaging
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. LOGIQ E9`s high
performance Harmonic Imaging provides superb detail resolution and penetration, outstanding contrast
resolution, excellent acoustic clutter rejection and an easy to operate user interface for switching into
Harmonic Imaging 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 (2D (B-Mode)) image quality without introducing a contrast agent.
5-2-6-2 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 (B-Mode) (B-Mode) image for spatial reference. The 2D (B-Mode) (B-Mode)
image has a graphical line (M-line) superimposed on the 2D (B-Mode) (B-Mode) image indicating where
the M-mode beam is located.
5-2-6-3

Color Flow 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 - used to visualize blood flow velocity and direction
• Power Doppler (Angio) - used to visualize the spatial distribution of blood
A real-time two-dimensional cross-section image of blood flow is displayed. The 2D (B-Mode) (B-Mode)
cross-section is presented as a full color display, with various colors being used to represent blood flow
(velocity, variance, power and/or direction). To provide spatial orientation, the full color blood flow cross-
section is overlaid on top of the gray scale cross-section of soft tissue structure (2D (B-Mode) (B-Mode)
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 be 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 (B-Mode) (B-Mode) and Spectral Doppler modes.
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Chapter 5 Components and Functions (Theory)
LOGIQ E9 S M
ERVICE ANUAL
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