2D Mode - Part 1

 
 
2D Controls
 
The imaging controls for 2D scanning are in five basic categories- Field of View (FOV), Gain, Color, Image settings, and Secondary modes. The basic setting are FOV, GAin and Color. These will be discussed in the section. To learn more about the advanced settings - Image and Secondary Modes - please refer to the Advance Section of e-Echocardiography.com. The field of view (FOV) can be changed by the depth, width and zoom controls. The zoom setting has a size and position setting. The gain setting is either global or sectional. Section gain is changed by the vertical settings or TGC and the horizontal setting or LGC. The color of the image can be set by the colorize control. The image quality can be changed by setting the frequency, focal zone or focus, compress, power, post processing, density, or persist settings. Other, secondary modes or controls of of the 2D mode are harmonic imaging or soft echo enhance.
 
In typical echo machines the compress, power, post processing, density, and persist settings are preset and usually do not require changing for image optimization.
 
  • Basic Settings
  • Field of View (FOV)
    • Depth
    • Width
    • Zoom
      • Size
      • Position
  • Gain
    • Global Gain
    • Lateral Gain
    • Temporal Gain
  • Color
    • Colorize

  • Advanced settings
  • Image
    • Frequency
    • Focal Zone
    • Compress
    • Power
    • Postprocessing
    • Persist
  • Secondary Mode
    • Harmonic Imaging
2D Controls
 
Field of View (FOV)
 
The field of view of the 2D scan consists of a width and depth of a scan which can be altered by the width and depth controls. A zoom control can enlarge an area of the scan depending upon its position and size.
 
Depth
 
The depth setting controls the vertical depth of the acoustic field of view. As the depth of the field of view is increased, several effects occur. An increase in the depth increases the scan time along a single scan line since the signal must be transmitted farther before it returns. Therefore, the transmit time and the receive time is increased. The increased time per scan line increases the time per frame which will cause the frame rate to decrease and may make the scan appear slower. If the depth is increased far field structures may not be easily discernible. To improve the penetration in the far field, the frequency must be decreased. The loss of increasing the frequency is the decreased resolution in the near field. Also, the transmit zone (discussed next), may be adjusted to the lower depths of the sector scan. While the results of a far field transmit zone may not be optimal, it may provide enough resolution and penetration to adequately visualize the far field structures. In color flow doppler the maximum velocity that is detectable also drops as the depth is increased. For similar reasons as 2D scanning, the increased scanning time causes the maximum detectable velocity to be decreased.

Normal Depth
 



 
Sector Scan Size
 
The width and size of the scan can be manipulated utilizing the trackball. The width and size can be either increased to the maximum or decreased to a small field of view by moving the trackball. The position of the field of view can also be changed by using the trackball. Advantages of using this setting to look at a particular area are to "blackout" the other part of the scan that may be confusing the interpretation of the scan. Also, decreasing the size of the scan increases the frame rate, so fast cardiac events may be easier to interpret. Manipulation of the size and position of the sector scan applies to 2D and Color Flow Doppler modes.