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SC2000 Pulsed Wave Doppler, Color Doppler, and M-Mode

This web-based training is designed to provide the US technologist and physician with relevant information to enhance and improve their clinical knowledge of the ACUSON SC2000 ultrasound system. This module will focus on the features and functions of the system required to successfully optimize Pulsed wave Doppler, explain color Doppler principles and optimize the color Doppler, and focus on optimizing the M-mode.

Learn@Siemens ID 00297945

Welcome to the Pulsed wave Doppler, Color Doppler, and M-Mode course for the ACUSON SC2000™ volume imaging system, version 3.0 and lower. To determine your version, follow the steps below: Choose F4 Choose System Settings Choose Service Your version will be listed under System Information/ Product Version. If you do not have version 3.0 or lower, please close this web based training and launch the other web based training for version 3.5 and higher.   You should now be able to: Describe the types of information obtainable using Doppler Identify the Keyboard layout and optimization controls Optimize Pulsed wave Doppler using all of the features and functions on the SC2000 system Explain Color Doppler principles Identify the features of the keyboard Identify the 3 Color Doppler types List and identify the LED panel functions Optimize the Color Doppler using all of the features and functions on the SC2000 system Activate and Optimize M-mode on the Acuson SC2000 system Make adjustments to M-mode Gain Adjust dynamic range Change the transducer frequency utilizing the MultiHertz key Optimize M-mode using the LCD control panel Thank you! Doppler Principles What does Doppler tell us? Direction of flow Velocity of blood flow Variance - range of velocities                 The following are trademarks of Siemens Medical Solutions USA, Inc.  (syngo® is a trademark of Siemens AG): ACUSON SC2000™ volume imaging ultrasound system DTI™ Doppler tissue imaging capability MultiHertz™ multiple frequency imaging RES™ enhanced resolution imaging Space-Time™ resolution control Doppler Modes Pulsed Wave: • Range specific (+) • Subject to aliasing (-) Continuous Wave: • Not subject to aliasing (+) • Not range specific (-)   Auxiliary CW (Peidoff transducer): • Small size/footprint for ease of access (+) • Non-imaging (-) Keyboard Layout We are now going to move to the keyboard layout and the optimization controls for pulsed wave Doppler. Pulse wave Doppler control:   Push the PW Knob to activate the cursor Push the PW Knob again to display spectral analysis While spectral analysis is active, adjust the gain by rotating the PW Knob or the FRINE Wheel                                                                                                    Continuous Wave Control For Continuous wave control:   Push the CW knob and adjust the cursor position Push the CW knob again to activate Rotate the continuous wave knob to increase or decrease the continuous wave Doppler gain during the real-time imaging   The FRINE wheel  may also be rotated to increase the Doppler gain or decrease the Doppler gain anywhere along the line.         Optimization Controls Doppler Gain: Controls overall amplification of returning Doppler signal Gain setting appears in data field Doppler Gain is independent of 2-D Gain                                                                                                                                                        Scale Scale is optimized to detect flow. Adjust to optimize display based on velocities represented by Doppler signal: Maximize use of display area Increase accuracy of measurements Avoid aliasing            DTI Doppler Tissue Imaging or (DTI) allows you to activate or deactivate pulsed wave DTI capability to show movement of tissue: Press the PW/PW DTI soft key When you activate DTI capability, the system adjusts the velocity scale to emphasize low myocardial velocities and adjusts the Doppler spectrum setting and the Doppler gate size to the last value set Baseline Shifts baseline up or down to increase proportion of display in favor of direction of flow Allows for lower scale setting (larger spectral waveform) without aliasing Adjusts the position of the baseline for optimal display of the PW or CW Doppler signal Press the Baseline toggle up/down to adjust the baseline position Note: The baseline may be adjusted during real-time imaging or on a frozen image.                                                                                                                               Invert Inverting the Spectral Display:  Switches display of flow toward transducer to below baseline Rarely used in adult cardiac studies Used frequently in vascular studies                          Sweep Sweep Speed adjusts temporal axis of Doppler display: Duration, Slope, dP/dT Rotate the sweep speed rotary knob to adjust the sweep speed for strip modes Using a high sweep speed will result in fewer cardiac cycles being displayed on the Doppler strip Using a low sweep speed will result in a greater number of cardiac cycles being displayed on the Doppler strip Note: Sweep speed may be adjusted during real-time or on a frozen PW or CW Doppler strip.                                                               Update The Update key refreshes 2D mode or color flow data during Doppler acquisition.               Priority Priority:                                                               Cycles through the activated imaging modes and displays the associated trackball controls, menus, soft keys, and other controls EXAMPLE:   If 2D-mode and Color are activated and 2D-mode is the priority mode, press Priority                      to activate the controls associated with color imaging.                                        Dynamic Range Dynamic Range Controls range of returning signal amplitudes that are displayed: Higher dB settings produce softer spectral image Lower dB settings produce a higher contrast spectral image       Persistence Persistence is a temporal smoothing process: Lower persistence setting provides crisper spectral Doppler display Higher persistence setting provides better fill-in, softer spectral Doppler display              Gate Gate:                                                               Improves sensitivity by increasing flow sample volume: Affects spatial resolution and frame rate Clinical Applications: Intramural coronary flow Shunt flow Tissue Doppler                    Doppler filter  The Doppler filter is used to:  Reduce noise and wall motion artifact Low filter settings provide minimum reduction of signal High filter settings provide maximum rejection of low level, low velocity signal May affect appreciation of spectral broadening Eight filter levels (1-8), increasing incrementally                             Edge Edge is a spatial smoothing process:     Edge setting of +1 provides crisper spectral Doppler display Edge setting of 0 provides better fill-in, softer spectral Doppler display            Post Processing Post processing: Enhances Doppler aesthetics by grayscale assignment Lower to higher contrast (maps 0-7) Does not affect data content Available in active, freeze and Cine MultiHz (Frequency adjustment) PW Doppler imaging frequency may be adjusted in real-time, independent of the 2D imaging frequency: The frequency range in PW Doppler is dependent on the active transducer 3 available frequencies 2.0 MHz, 2.5MHz and 3.5MHz MultiHz toggle: PressUp to increase PW Doppler frequency PressDown to decrease PW Doppler frequency Upon successful completion of this course, participants will be able to: Describe  the types of information obtainable using Doppler   Identify the Keyboard layout and optimization controls   Optimize Pulsed wave Doppler using all of the features and functions on the SC2000 system   Explain Color Doppler principles   Identify the features of the keyboard   Identify the 3 Color Doppler types   List and identify the LED panel functions   Optimize the Color Doppler using all of the features and functions on the SC2000 system   Activate and Optimize M-mode on the Acuson SC2000 system   Make adjustments to M-mode Gain   Adjust dynamic range   Change the transducer frequency utilizing the MultiHertz key   Optimize M-mode using the LCD control panel   Doppler Principles   Color Doppler: Imaging Technique Displays mean velocity and variance within an area of the image Spectral Doppler: Graphic Technique Displays peak, mean and range of velocities at a single point along the Doppler beam (PW) or along the entire beam (CW) The Doppler Effect A shift in frequency caused by the relative movement of either the sound wave source, the sound wave reflector or the sound wave receiver: The transducer is the sound wave source and receiver The red blood cells are the sound wave reflectors: RBC’s moving toward the transducer compress (increase) the frequency RBC’s moving away from the transducer expand (decrease) the frequency Angle to Flow Best Doppler angle is parallel to flow and closest to 0°. The Angle is affected by: Transducer position Patient position Color sensitivity An instrument’s ability to extract maximum flow information and its ability to allow the clinician to visualize it as pathology: High dynamic range Low noise electronics Highly sensitive transducers An instrument’s ability to resolve hemodynamic events and display them in their correct anatomical locations: Small vessels Intramural coronary tributaries Vasa vasorum Discrete separation of multiple jets   Temporal Resolution An instrument’s ability to display rapidly changing hemodynamic flow states in real-time is influenced primarily by frame rate: Superior flow dynamics Concomitant flows Short duration jets   Image Display In this next section we will discuss aspects of achieving the most from color Doppler regarding the color Doppler image display including the following topics: The Color Bars Color Doppler Controls Tips and Techniques The Color Doppler Bar Color represents mean velocity at the sample area: Toward the transducer is one color (i.e., red) Away from the transducer is another (i.e., blue) Shade indicates the velocity of blood flow: Deep shades indicate low velocities Lighter shades or a change in color indicate higher velocities Velocity scale indicators appear at each end of the bar: Baseline indicator or “0” velocity Velocity scale indicators appear at the ends of the color bar Mean velocity and direction:   Map 1-5 Directional speed maps Map A Standard proposed by the ASE Map S Non-directional speed map Use when direction information is undesirable VAR 1-3 Variance maps Velocity-Variance (VV) Maps Amount of variance is mapped:   Laminar flows have little or no variance     Turbulent flows often have significant variance: Stenosis Regurgitation   Vertical axis: Mean velocity: Horizontal axis: Variance Highest velocity along right side of bar Velocity Scale The velocity scale in color Doppler High scales for high flow states and uses. High scales for high flow states: General cardiac Doppler Higher range of velocities Low scales for low flow states: Coronaries, PISA detection Sensitive to motion artifact Keyboard Layout Controls are logically grouped based on mode Left side controls are for 2D imaging Right side controls are for Doppler Color Control The color control C knob will activate color Doppler when depressed: Press C knob to activate color Doppler Rotate C knob to increase/decrease color Doppler gain during real-time imaging Adjusting Positioning and Size: Make positioning and size adjustments with the Next key Next key cycles through the imaging mode tools currently controlled by the trackball EXAMPLE: (Tab 1 below) During 2D imaging, press Next to activate the position or size the field of view.  When the trackball is assigned to the pointer function, Next is equivalent to the right mouse button on a computer. See Tabs below for Select Keys:   Update (Top Left) refreshes 2D-mode or color flow data during Doppler acquisition Priority cycles through the activated imaging modes and displays the associated trackball controls, menus, soft keys, and other controls EXAMPLE: During 2D imaging, press NEXT to activate the position or size the field of view.  When the trackball is assigned to the pointer function, NEXT is equivalent to the right mouse button on a computer. Refreshes 2D-mode or color flow data during Doppler acquisition. Cycles through the activated imaging modes and displays the associated trackball controls, menus, soft keys, and other controls. EXAMPLE: If 2D-mode and Color are activated and 2D-mode is the priority mode, press PRIORITY to activate the controls associated with color imaging. The ACUSON SC2000 system offers three color Doppler settings  Color Doppler Velocity (CDV) (everyday color) Applies color to the velocity and direction of blood flow within the region of interest The benefit of CDV is excellent sensitivity to flow with direction and velocity information   Applies color to the mean velocities of tissue in the ROI Can be used for timing    Applies color to the Doppler signal energy returning from the tissue •   Enhances myocardium     Activating Color Doppler Velocity  Use the soft keys to cycle between: Doppler Tissue Velocity Doppler Tissue EnergyActive mode will be displayed in green Baseline The system updates the position of the baseline. Indicator of 0 velocity Shifts baseline up or down to increase proportion of display in favor of direction of flow Allows for lower scale setting (larger spectral waveform) without aliasing Toggle key up or down to adjust the color, pulsed or continuous wave baseline Scale  (Pulse Repetition Frequency-PRF) Represents the mean velocity at the sample area toward or away from the transducer. Adjusts the velocity scale of color Doppler (M/sec). Press the toggle up or down to adjust the velocity scale White box indicates maximum velocity Note: In color Doppler, adjusting the velocity scale will show changes in the velocities listed on the color bar. Invert The invert key will change the orientation of the Color Doppler Velocity display: Reverses colors or spectral analysis above and below baseline as determined by transducer location and direction of blood flow Selecting Flow State (Image Control) In color Doppler imaging, each preset has been optimized with image settings optimized to flow state. The following image settings are available: General Low High Frame Rate Image Control Knob Instant optimization Modality specific Affects active mode only “Look” oriented Does not reformat image Changes image appearance User can customize and store additional presets. MultiHertz imaging Independent 2D-mode & Color Doppler frequency Select highest frequency providing sufficient penetration Optimize for application and patient What CD Frequency should I use?  Slightly higher frequency for flows in smaller structures:  Coronaries Shunt flow  Lower frequency for best penetration: Typical Doppler valvular exams & general function exams Persistence Adjusts the time that color data remains in the region of interest Frame averaging: “Adds history” to the current image Affects temporal resolution: Perceived persistence is independent of frame rate May reduce hemodynamic information Helpful with difficulty detecting flow: Lengthens the display of color on the screen Smoothes color display Post processing (color maps) The Acuson SC2000 has a selection of a color Doppler mean velocity maps and velocity variance maps: Velocity maps: 1-5, A and S Velocity-Variance maps:  VAR 1-VAR 3 Personal choice   Modify: Tag Velocities above a threshold velocity Velocities below a threshold velocity Range of velocities Range or threshold set by operator Accent: Highlights (brightens display of higher or lower velocities) Mix: Provides transparency to color display Allows 2D-mode information to show  through Color LED Panel The LED panels provide functions based on the current system state or operating mode that is under the filter: SpaceTime Edge Filter Capture One Beat/Capture One Second Map/Transparency Display B&Color NOTE: Rotary knobs 4, 5, and 6 are dual controls. Pressing the LED rotary control alternates the selections. Controls priority for spatial or temporal resolution “S” preference toward spatial resolution “T” preference toward temporal resolution Linked 2D-mode SpaceTime control settings Note: Increasing spatial resolution decreases temporal resolution.Increasing temporal resolution decreases spatial resolution.       Edge is a Two-dimensional smoothing of echoes, it: Smoothes flow borders Maintains appearance of fluidity at higher SpaceTime control settings Affects the spatial resolution Use low edge settings for large vessels (General cardiac flow patterns) and high edge settings for anatomical detail (Small vessels or shunts).         Filter Adjusts the smoothness of the color image and the amount of color displayed: Used to reduce noise and wall motion artifact and enhance the smoothness of the color image by adjusting the level of motion discrimination Consistent across transducers  You can Increase or decrease level as needed.       Activating M-Mode: To activate M-mode press the M knob. Use the Trackball to adjust the M-mode cursor line position. Select Next to continue. Adjusting M-mode Gain: Rotate M knob or FRINE wheel to increase/decrease M-mode Gain during  real-time imaging. Rotate 2D knob to increase/decrease both M-mode and 2D-mode reference image gain. Select Next to continue. Dynamic Range: Dynamic Range allows the user to increase or decrease the number of gray levels available for the M-mode image. M-mode Dynamic Range adjustments are independent of 2D imaging Dynamic Range adjustments. Select Next to continue. Frequency Range: The frequency range in M-mode will be dependent upon the frequency of the active transducer. M-mode imaging frequency is dependent on 2D-mode reference image frequency. Select Next to continue M-mode LCD Control Panel The LCD Control Panel contains five controls used to optimize M-mode.  Click below to view the details of each control. Roll over the Icons below to view the details of each control.

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