GE Logiq P5 User Manual

							Optimizing Color Flow
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Threshold
DescriptionThreshold assigns the gray scale level at which color 
information stops. 
AdjustingTo increase/decrease the gray scale threshold, press 
Threshold left/right. 
Va l u e sThe settings cycle through various values: 10%-100% of the 
gray scale. High values display more color; low values displays 
more B-Mode gray scale data. The Color Threshold level is 
displayed on the Touch Panel. 
Values vary by probe and application and are returned to factory 
or user preset value when you change: Probe, Exam Category, 
Exam Calcs, or New Patient. 
BenefitsLimits color flow overlay to low level echoes inside vessel walls. 
Helps minimize color `bleeding outside vessel walls. 
Frame Average
DescriptionAverages color frames. 
AdjustingTo smooth temporal averaging, select Frame Average left/right. 
The selected value displays on the Touch Panel. 
Va l u e s0-7, with 7=color capture; in PDI, 0-9, with 9=color capture. 
Frame Average values vary by probe and application and are 
returned to factory or user preset value when you change: 
Probe, Exam Category, Exam Calcs, or New Patient. 
BenefitsHigher frame averaging keeps the color displayed longer for 
increased flow visualization (decreased frame rate) while lower 
frame averaging provides greater flow dynamics (pulsing from 
increased frame rate). 
Affect on other 
controlsTrades off between frame rate and color quality. As the color 
quality increases, the frame rate may decrease and as the frame 
rate increases, the color image quality decreases.  
						

							Optimizing the Image
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Transparency Map
DescriptionBrings out the tissue behind the color map. 
AdjustingSelect Transparency Map to adjust
Va l u e s0-4
BenefitsHelps demonstrate the tissues behind the color. 
Spatial Filter
DescriptionSmooths out the color, makes it look less pixely. 
AdjustingSelect Spatial Filter to adjust. 
Va l u e s0-5
BenefitsSmooths the image. 
Duplex
DescriptionDuplex On: simultaneous B-Mode + Color Flow Mode. 
Duplex Off: Toggle live B-Mode and Color Flow Mode via B-
Pause. 
AdjustingSelect Duplex to adjust. 
Va l u e sOn/Off
BenefitsAllows the user to have both PW and B-Mode active at the same 
time. 
						

							Optimizing Color Flow
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Ace
DescriptionActivates/deactivates Adaptive Color Enhancement (Ace), a 
motion artifact elimination process. 
AdjustingTo adjust, select the next page and then select Ace. The Ace 
Touch Panel key is lit. 
Va l u e s0-4. 
Values vary by probe and application and are returned to factory 
or user preset value when you change: Probe, Exam Category, 
Exam Calcs, or New Patient. 
BenefitsAce: Beneficial when imaging slow flow states, especially with 
abdominal and OB applications. 
Packet Size
DescriptionControls the number of samples gathered for a single color flow 
vector. 
AdjustingTo increase/decrease the packet size, select Packet Size left/
right.
Va l u e sValues vary by probe and application and are returned to factory 
or user preset value when you change: Probe, Exam Category, 
Exam Calcs, or New Patient. Values are displayed on the 
monitor display as PSize. 
BenefitsAllows you to improve the color sensitivity and accuracy of color 
averaging (increase packet size) or frame rate (decrease packet 
size), as needed. 
Affect on other 
controlsWhen you decrease the packet size, you increase the frame rate 
at the expense of image quality. When you increase the packet 
size, you improve image quality at the expense of frame rate. 
BioeffectsChanging packet size may change the TI and/or MI. Observe 
the output display for possible effects. 
						

							Optimizing the Image
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Power Doppler Imaging (PDI) 
DescriptionPower Doppler Imaging (PDI) is a color flow mapping technique 
used to map the strength of the Doppler signal coming from the 
tissue rather than the frequency shift of the signal. Using this 
technique, the ultrasound system plots color flow based on the 
number of reflectors that are moving, regardless of their velocity. 
AdjustingTo activate/deactivate PDI, press PDI. 
Va l u e sOn/Off. 
Ten power (P0-P6 and P8-P10) and one Directional PDI map 
(P7) is available. 
BenefitsBecause PDI does not map velocity, it does not display aliasing. 
Affect on other 
controlsWhen PDI is activated, the following controls are adjusted: 
Focus Number may be up to four focal zones. PRF is set to a 
lower setting. Color Map is set to a power map. FR/RES is 
adjusted. Wall Filter is set to a lower setting. Threshold is set to 
100%. Frame Averaging is adjusted.  Packet Size is set to 16. 
NOTE:  These controls are reset to their previous values upon exiting 
PDI. 
HINTSWhen changing maps, higher gain settings may be needed. 
P-1. The expanded map is designed to expand or increase the 
dynamic range of data displayed in a PDI image to show both 
low and high flow states. It is especially useful for highlighting 
very low flow states just above the noise floor as in renal 
vessels. 
P-3. The compressed map is designed to compress or 
decrease the dynamic range of the PDI image data to highlight 
high flow states and suppress noise. 
P-7. Directional PDI displays the direction of flow while in 
Power Doppler Imaging. Gives all the benefits of PDI while also 
providing directional information not available in traditional PDI. 
Used in applications where sensitivity and angle independence 
is desired, but directional information is also required. Flow 
towards the transducer is red; flow away is dark blue to light 
blue. 
						

							Optimizing Color Flow
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Directional Power Doppler
You can select the P7 Directional Power Doppler map while in 
PDI. 
NOTE:  If you store a PDI image and recall it, you can still switch to the 
Directional Power Doppler map and vice versa. However, an 
image stored as non-directional then switched to directional just 
adds direction to a non-directional map and vice versa. 
HINTSIf the image is aliasing, increase the PRF and reduce the Wall 
Filter.  
						

							Optimizing the Image
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Optimizing Spectral Doppler
Intended Use
Doppler is intended to provide measurement data concerning 
the velocity of moving tissues and fluids. PW Doppler lets you 
examine blood flow data selectively from a small region called 
the sample volume. 
Typical Use - PW Doppler
In Pulsed Wave Doppler (PW) Mode, energy is transmitted from 
the ultrasound probe into the patient, as in B-Mode. However, 
the received echoes are processed to extract the difference in 
frequency between the transmitted and received signals. 
Differences in frequencies can be caused by moving objects in 
the path of the ultrasound signal, such as moving blood cells. 
The resultant signals are presented audibly through the system 
speakers and graphically on the system display. The X axis of 
the graph represents time while the Y axis represents the shift in 
frequency. The Y axis can also be calibrated to represent 
velocity in either a forward or reverse direction. 
PW Doppler is typically used for displaying the speed, direction, 
and spectral content of blood flow at selected anatomical sites. 
PW Doppler operates in two different modes: conventional PW 
and High Pulse Repetition Frequency (HPRF). 
PW Doppler can be combined with B-Mode for rapidly selecting 
the anatomical site for PW Doppler examination. The site where 
PW Doppler data is derived appears graphically on the B-Mode 
image (Sample Volume Gate). The sample volume gate can be 
moved anywhere within the B-Mode image.  
						

							Optimizing Spectral Doppler
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Typical exam protocol
A typical examination using PW Doppler Mode might proceed as 
follows: 
1.  Connect the appropriate probes, leaving the probes in their 
respective holders. 
2.  Position the patient for the examination. 
3. Press Patient. Enter the appropriate patient data using the 
appropriate exam category and worksheet. 
4.  Engage the probe to be used by lifting it out of its holder. 
5.  Locate the anatomy to be examined. Get a good B Mode 
image. Refer to B-Mode section of this chapter for more 
information. 
6. Press M/D Cursor to display the sample volume cursor and 
gate. 
or
Press PW. The PW Doppler spectrum appears and the 
system operates in combined B+Doppler Mode. Adjust 
Vo l u m e to adjust Doppler audio. The Doppler signal is 
heard through the speakers. 
7.  Position the sample volume cursor by moving the Trackball 
left and right. Position the sample volume gate by moving 
the Trackball up and down. Size the gate by clicking SV 
Length. 
8.  Optimize the PW Doppler spectrum, as necessary. Refer to 
the Doppler Optimization section of this chapter for more 
information. 
9.  Sample along the whole length of the vessel. Make sure that 
the probe is parallel to flow. Listen, then look, when 
positioning the sample volume cursor. 
10. Press Freeze to hold the trace in memory and stop imaging. 
Activate CINE Timeline, as necessary. See “Activating 
CINE” on page 1-5 for more information. 
11.  Perform measurements and calculations, as necessary. 
Refer to the Measurements and Calculations chapter for 
more information.  
						

							Optimizing the Image
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Typical exam protocol (continued)
12.  Record results by pressing P1 - P4, depending on the setup 
of your recording devices. 
13. Press Freeze to resume imaging. 
14.  Repeat the above procedure until all relevant flow sites have 
been examined. 
15.  Replace the probe in its respective holder. 
Activating CW/PW Doppler Mode
To activate CW or PW Doppler Mode, press CW or PW. 
The Doppler spectrum displays along with the B-Mode image. 
The cursor changes to a Doppler cursor. 
You can now position and size the sample volume gate to get a 
velocity. Use Doppler Audio to listen for when the sample 
volume gate is positioned over an area of flow. 
UseDoppler is used to examine blood flow information in the vessels 
of the legs, arms, abdomen, neck, and heart.  
To exit PW Doppler Mode, press PW; CW Doppler Mode, press CW. 
Activating Triplex Mode
To activate Triplex Mode, press CF. Press PW. 
The Doppler spectrum displays along with the Color Flow and B-
Mode image. The cursor changes to a Doppler cursor. 
You can now position and size the sample volume gate to get a 
velocity. Use Doppler Audio to listen for when the sample 
volume gate is positioned over an area of flow. 
UseTriplex Mode is used to examine blood flow information in the 
vessels of the legs, arms, abdomen, neck, and heart.  
To ExitPW Doppler Mode, press CF, then PW.  
						

							Optimizing Spectral Doppler
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Doppler Display
Time zero (the start of the trace) appears on the left side of the 
graph. As time progresses, the trace moves to the right. The 
baseline of the graph (representing zero velocity, zero frequency 
shift, or no detected flow), appears as a solid line running 
horizontally across the display. By convention, movement 
toward the probe is positive and movement away from the probe 
is negative. Positive frequencies or velocities appear above the 
baseline. Negative frequencies or velocities appear below the 
baseline. 
Typically, blood flow is not uniform but is composed of a mix of 
blood cells moving at different velocities and in different 
directions. Thus, the display is composed of a spectrum as gray 
scale values. Strong signals are displayed as bright while weak 
signals are displayed as varying shades of gray. 
HPRF is invoked when you are operating in PW Doppler Mode 
and conditions activate HPRF (when the velocity scale factor or 
sample volume gate depth exceeds certain limits). When HPRF 
is active, multiple sample volume gates appear along the 
Doppler mode cursor. Doppler information can be received from 
any of the multiple sample volume gates. The Doppler signals 
from all the gates are added together and displayed in one 
spectrum. 
Information about the PW Doppler display is automatically 
written on the screen and updated when scanning parameters 
are changed. 
This chapter includes: 
•  A discussion of PW Doppler. 
•  Activating Pulsed Wave Doppler. 
•  Optimizing the Doppler spectrum. 
Imaged Doppler
When you view the PW Doppler spectrum and a B-Mode image 
with a 3.5 MHz probe, this means that you are viewing the 
image at 3.5 MHz and `Dopplering at 2.5 MHz.  
						

							Optimizing the Image
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Doppler Mode Display
 Figure 5-15. Doppler Mode Display
Table 5-3: Doppler Mode Display Explanations
Doppler DisplayDescription, Format, Values
PRF Pulse repetition frequency, displayed as PRF in kHz. 
Wall Filter Wall filter size, displayed as WF in Hz. 
Doppler Gain* Displays asGN in decibels (db). 
Sample Volume 
DepthDisplays (in Cm) when Doppler cursor is present.  
Doppler Angle
 (AC ##)Indicates angle in degrees between the Doppler mode cursor and the angle 
correction indicator. Displays when Doppler cursor is present. The Doppler 
Angledisplays in red when the angle exceeds 60°. Velocities obtained when the 
angle is greater than 80° are displayed as asterisks (***). 
Spectral Invert INVERT appears when the spectral trace is inverted and the plus/minus signs (+/-) 
are reversed.