If the automatic matching rigid matching is not working properly for a combination of images, the use of fiducial markers should be considered. In the example below three capillaries filled with activity were attached to the bed of the mouse, and then imaging performed on separate CT and PET systems. The capillaries are clearly visible in the CT, whereas the activity in the inner of the capillaries is picked up by PET. The tubes were plugged by a small plasticine plugs, which can be seen by zooming in on the CT image. Consequently, the end of the capillary activity in PET should correspond to end of the plug in CT.
For marker matching, the user explores the two image sets and marks corresponding locations, i.e. markers. A transformation is then calculated which brings the two spatial arrangements of markers into optimal agreement.
Please first load the input images on the LOAD INPUT IMAGES sub-page and make sure the Species setting is correct. To proceed select the Markers matching as Matching method.
On the REFERENCE &Matching sub-page load the reference image with the REF: Load button. Next start landmark definition with the Set markers button.
Marker Definition for the Reference
Marker Definition for the Input
The next task is the definition of the corresponding landmarks for the input image.
As the image content is not used for the registration, only parameter is whether the transformation is strictly rigid, or whether a scaling is allowed (Rigid + Scale option).
Starting Markers Matching
Please use the Match Current button to start the registration of the two sets of landmarks.