Window/Level Settings

 

Window width and center values are applied when the image is first placed in an image frame. The viewer applies the window and level values in the following order:

  1. Preset values assigned by the applied hanging protocol

  2. VOI LUT defined by the image object

  3. Defined values included in the image object

  4. Calculated values based on a histogram equalization algorithm

To adjust the window width, select the image frame, hold down the right mouse button and drag the mouse to the left and right. To adjust the window center, hold down the same button and drag forward and back. The applied values appear in the Window/Level toolbar.

 

Imaging modalities and PACS systems may change the image objects, causing rendering problems in third party systems. If you have problems with the default window/level settings, some adjustments are possible.

  1. Click Settings/Customize Settings/Images.

  2. Under the W/L range field, set the minimum and maximum window and level settings for each modality. If you need to use the defined range, select Automatic.

Some modalities define a window width reflecting the full range of pixel data, with a center value set to the middle of the range. The viewer applies the defined values, even when they result in a poor image. To produce a quality image, you may have to manually set the window and level. You may need to ignore the predefined window and level settings. The viewer then uses its own analysis to set these values. To disable the default window width and center in an image object, follow these steps:

  1. Click Settings/Customize Settings/Image.

  2. Under settings for, select the modality you want to ignore the default settings, or choose default to set a default setting. 

  3. In the auto W/L setting section, place a checkmark in the use default override field if you want to apply the default setting to the selected modality, or select another setting. 

  4. If you select no override, the viewer uses the defined window/level settings in the image object. 

  5. If you select override by Study/Series/Image, the internal analysis program will be used.

  6. The optimal setting is override by series.

Some images arrive on the PACS system with explicitly defined window and level values for each image. To override explicitly defined W/L settings and apply a single value to all images in the series, use the unified window/level setting, available as follows: