Inobitec DICOM Viewer

2.16. Dynamic contrast-enhanced MRI and CT View Mode


Functionality is available in the Pro edition

Dynamic contrast-enhanced MRI or CT are imaging methods where images are acquired dynamically after injection of a contrast agent what allows to view the "wash-in" and "wash-out" of contrast. To open this mode select the Image main manu and the DCE menu item. The DCE panel will be shown on the right (Fig. 2.16).

To change the size and the configuration of panel, move its borders (highlighted by red arrows in Fig. 2.16). To do this, move the cursor to the panel border so that it would look like this: PIC , and drag the border holding the left mouse button. If you strongly reduce the panel, it closes.

2.16.1 Map Settings

Map Settings panel is located on the bottom part of the DCE Panel (Fig. 2.17).

The following parameters can be set:

  • Map Type (None, Time Peak, Slope, Area);
  • Config, or CLUT;
  • Minimal Signal: the map will be built for the tissue with signal level greater than the specified;
  • Minimal;
  • Maximal;
  • Transperency.

After you enter numeric values, press the Enter key on the keyboard and the entered values will be applied. Color card shows how quickly change the concentration of a contrast agent in the tissue.

2.16.2 Detection of tumors using ROI

Measurements are performed with the ROI tools (point PIC , rectangle PIC , ellipse PIC and polygon PIC ). The tool buttons are in the top of the DCE Panel. Attention! Since version 1.11.0 similar tools located on the toolbar of the View Flat Images window and in the Image item of the main menu can not be used to detect tumors!. The tools are described in Section 2.15.5. Dy default annotations are not displayed.

A graph of the signal average value in ROI is shown at the top of the DCE panel. The graph color corresponds to the ROI color. To hide the graph, select the Hide value from drop-down list on the ROI panel, to show the graph, select the Show value.

The values of the Ktrans, Kep and Vp peremeters are shown on the DCE Panel.

To build a signal change graphics for plasma and tissues:

  1. Select the ROI corresponding to plasma and ROI, corresponding to tissue on the ROI Panel on the bottom of the DCE Panel. At the same time each value can be set for only one ROI. If the value is already set for another ROI, then for him the value will be changed to Show.
  2. Select the type of graph from the drop-down list (Fig. 2.18):
    • Signals (set by default). All graphics except hidden are shown.
    • Concentration. Graphics corresponding to Plasma and Tissue are shown. The solid lines shows the graphics and the dotted line shows the approximation.
    • Approximation. This type is analogous to the previous one, the solid line shows the approximation and the dotted lines shows the graphics.
  3. If necessary, set the Begin and End frames by entering the values under the graphics or moving the border of the graphics manually. To do this, move the cursor to the border so that it looks like PIC and move the border holding the left mouse button.
  4. Set the parameters T10 for tissue and plasma. To do this click the Estimate button to the DCE panel. In the dialog box that opens, select the value entry mode:
    • Manual (Fig. 2.21). Enter the values from the keyboard.
    • From table (Fig. 2.22). Select the values from the table.
    • Estimate (Fig. 2.23). If the study contains a series made without contrast, this series is used as a reference. Select it from the drop-down list Series and click on the Estimate. Below the calculated values are displayed, which can be adjusted manually.

      If the study contains a series without contrast, this series is used as a reference. Select it from the drop-down list Series and click the Estimate button. The calculated values will be displayed below. You can adjust its manually.

    To build a graph by the present values, click OK, to cancel click Cancel. Graph type will be changed to Concentration and graphs will be rearranged in accordance with the preset values.

The two fillowing figures illustrate examples of concentration measurement. The Fig. 2.24 shows the graphs for plasma (red) and healthy tissue (green), and the Fig. 2.25 shows the graphs for plasma (red) and cancerous tissue (yellow). The map transparency is set to zero.

The following three figures illustrates three map types for this study.

The vertical yellow line on the graph shown in fig. 2.24 corresponds to the current phase of the study. To change the phase move the cursor to the line so that it would look like PIC and drag the line holding the left mouse button.