1. Import two maps/geometries. In this example, we used Rhythmia LV map and InHeart 5mm wall thickness geometry. 

2. Select 2nd geometry (InHeart in our example) and turn off “Display geometry” box so that only 1st geometry (Rhythmia map in our example) is visible.

3. Now we will be placing three “registration points” that will be used to put 2 geometries together in space. It is good that they are in specific anatomical locations. In case of LV, good locations are: apex, base-lateral, base-septal. To locate point, right-click on the map and select: “Set registration point” (A, B or C). (in our example we put point C at apex)

and A and B points on the base:

 

4. Next step is to do the same for 2nd geometry. 

5. Turn off display of 1st geometry (Rhythmia).

6. Change geometry to 2nd (InHeart). Turn on display of this geometry, so you have this view:

 

7. Now, mark 3 points on this geometry. Of course be sure that they are in the same anatomical locations. At the end you should have something like this:

8. Once all ABC points are located on both geometries, it’s time for spatial registration. First, turn on display of all surfaces (so that you see all fitted geometries).

9. Perform registration by selecting in main menu: 

10. Now important step (it is very important to understand this step well). You have to decide which geometry will be moved in 3D space trying to fit other geometry. So we have “geometry that will be moved” (which is currently selected geometry) and “base geometry” (that will remain fixed in 3D space and to which 1st geo will be moved). So:

a. Select which geometry will be moved in 3D space (in case of Rhythmia + InHeart it may be best to select Rhythmia to be moved.

b. Select from menu “ABC to ABC fitting”.

c. In dialog box put 2, so that InHeart geometry will be “base geometry”.

11. You should now see how 1st geometry is moved and fitted to the “base geometry”. App will perform 200 steps of fitting (may take few sec).