Windowing button is used to adjust image contrast and brightness (Level and Window values). You can change the brightness using the mouse or from the menu.
For changing the brightness with mouse, assign the mouse button to Windowing function . Hold down the assigned button and drag the mouse upwards or downwards (to change Level values), and right or left to change Window values.
The windowing values may be applied for the same series in different viewports. By default, this feature is disabled, and you should use the Sync Windowing for Same Series menu to enable it.
NOTE! Sync Windowing feature is also applicable for the reconstructed orthogonal series.
Also, you can click the red triangle on the right of the button and select the windowing from the menu:
Figure 13. Window button menu example
The brightness level menu consists of static and dynamic elements - groups and options. Dynamic menu elements are only displayed if they are applicable to the active image.
The description of Windowing menu elements:
- Static group DICOM Windowing. Group contains the following options:
- Auto – the system analyses the image and adjusts the brightness and contrast automatically. Static menu option. Auto windowing is applied if no other options are available in DICOM Windowing group.
- Dynamic menu options - all the Window and Level value pairs from image DICOM data: windowing title, w value, and l value are displayed. The first option is automatically applied, if available.
- VOI LUT (Value of Interest Look-Up Table) dynamic group is displayed only if VOI LUT configurations are found in image DICOM file. This transformation gives greater weight to the range of values of interest. The DICOM Standard Window Center and Window Width are linear VOI LUT where only 2 parameters are specified - center and width of the interval. Meanwhile, the non-linear VOI LUT uses a free shape curve in the form of a table. In AlemHealth user environment VOI LUT is called non-linear transformation.
- The VOI LUT group displays all VOI LUT configurations that are available in the active image DICOM file. The names of VOI LUT configurations specified in the DICOM file are displayed. If VOI LUT configurations exist, the first VOI LUT configuration is automatically applied, along with Auto w and l values.
- The Color LUT group displays the COLOR PALETTE menu, if COLOR PALETTE is found in image DICOM file. If there is a Color Palette, it will be applied during the study loading process. After applying another Window Leveling perfusion, the Color palette will not be applied automatically. To apply the color palette after changing the windowing level, click the COLOR PALETTE menu.
- Custom Windowing dynamic group holds the custom windowing options if the active image modality has any available.
- Invert – the static option that is used to invert the image.
- Sync Windowing for Same Series – static option that allows applying windowing values for the for the same series displayed in different viewports (including MPR projections). Windowing synchronization is enabled if the synchronized windowing icon on the left side of the menu is highlighted . Windowing synchronization settings are stored in your browser's local storage and only apply to the same browser.
- Color Palette Selection – static option that enables applying color palette for the series in the active viewport (see section Color palette for monochrome images). Color palette selection is enabled if the icon on the left side of the menu is highlighted .