DTI fMRI

You can also import activation regions as ROIs. Click on the ``Import Activation regions as ROIs'' button to launch the wizard. The first step is a binarization of the image in order to avoid noisy regions (see Fig. 3.19). Click on the ``open'' button to load the activation map. Left screen is the transversal view of the activation map shown in grey level. The screen on the right is the binarized image by a threshold that you can change thanks to the slider on the top of the window. You can navigate in the volume by moving the mouse up and down while left-clicking on one of the view. When you have finished binarizing the image, click ``next''. MedINRIA will automatically find the activated regions, cluster them and associate a different color for each.

Figure 3.19: This is the first step in the transformation of fMRI activated regions into DTI Regions Of Interest. It corresponds to a binarization of the activation map in order to avoid noisy and non-relevant regions. The slider controls the binary threshold. The left screen is a transversal view of the original activation map. The right screen is the result of the binarization. You can use the mouse to navigate in the volume (see Section 3.3.1).

The last step of this importation wizard allows you to select the activated regions you want to consider as Regions Of Interest. In figure Fig. 3.20 you see a 3D view of these activated regions. You can distinguish them by color. Select those you want to consider as ROIs in the list box on the left (see Fig. 3.20). To help you in this choice, a summary of the regions is shown on the lower left part of the window, displaying the volume of each region (in voxels). You can also save the current selection for future use.

Figure 3.20: Second and last step of the transformation of fMRI activated regions into DTI Regions Of Interest. You can see a 3D view of activated regions that have been colored. On the left you can select relevant activated regions that will become ROIs. To help you in this choice there is a summary of the different regions (number of points per region). You can also save the current selection for future use. Click finish to validate your selection.

When you have finished selecting the regions, click ``finish''. The regions will become ROIs in the DTI-study you are using. You can now track the fibers that go through the activated regions you imported ! Note that the activation map must have the same dimensions as the volume currently visualized in MedINRIA. If the activation map you want to import doesn't have the same dimensions as the DWI of your DTI-study but has the same dimensions of the corresponding T1 image. You must first create a DTI-study indicating the registration matrix to use between T1 and DWI, second load the T1 image inside the DTI-study, and finally import the activation map to create ROIs.