Select the CLUT (colour look-up table) from the drop-down menu on the rendering setup panel (Fig. 2.17).
To edit the list, open the CLUTs setup tab by clicking the CLUTs button. The tab is shown in Fig. 2.18.
CLUTs setup panel is located on the right-hand side of the window (Fig. 2.19).
|Add a new CLUT as a copy of the current one adds a new CLUT as a copy of the selected one|
|Add a new group adds a new group of CLUTs|
|Remove the selected CLUT/group deletes the selected CLUT or group. Predefined groups and some CLUTs cannot be deleted|
|Reset the selected CLUT to its original state sets up default parameters for the selected CLUT|
|Edit configuration/group opens the CLUT or group setup dialog|
To add a new group, set the following parameters in the dialog box (Fig. 2.21):
To browse the settings for the selected CLUT, click the Rendering transfer function button. The panel displaying the visualization transfer function graph will appear at the bottom of the study window (see the example in Fig. 2.22).
You cannot change the setup parameters for predefined CLUTs.
Intensity will be displayed on the horizontal axis, while the number of points with a particular intensity will be shown on the vertical axis (blue line). The default scale may not allow you to see the intensity distribution graph (blue) at once. To change the horizontal axis scale, move the scroll under the axis or roll the mouse wheel while the cursor is located on the scrollbar. The scale value will be displayed to the right of the scrollbar. To change the vertical axis scale, roll the mouse wheel while the cursor is located on the visualization setup panel, but not on the scrollbar. Fig. 2.23 shows the same graph as in the previous figure, but with a greater intensity distribution scale (on the vertical axis).
The color/transparency chart (white line) is superimposed on the intensity distribution scale. The horizontal axis shows the intensity, and the vertical axis shows the transparency of the color highlighting the points with this intensity. The color is displayed below the graph. The horizontal axis scale changes for both graphs simultaneously, while the vertical axis scale for the color/transparency chart does not change. To move the graph along the horizontal axis, hold the left mouse button.
To find out what percentage of tissue has a density in a given range, click on the Histogram percentage button, move the cursor to the beginning of the range and move the cursor to the end of the range, holding the left mouse button. The percentage of tissue that has a density within the range is indicated in red (fig. 2.24). To edit a range, move the cursor to its border and move the border with the left mouse button pressed. To move a range, move the cursor on it so that the cursor would look as follows , and move the cursor, holding the left mouse button. Multiple ranges can be built at the same time. To remove the built ranges, click the Histogram percentage button again.
To export data on the distribution of densities, click on the button, in the dialog that opens, specify the file name and folder, click Save to finish or Cancel for cancel.
To create your own CLUT:
To delete a CLUT, click the Remove the selected CLUT/group button.
The DICOM Viewer allows you to add additional color/transparency charts. To add:
If the chats overlap, the colors are mixed.