Image fusion between ultrasonography and CT, MRI or PET/CT for image guidance and intervention - a theoretical and clinical study.

The aim of this thesis was to test the clinical application of image fusion involving US. The first study describes the accuracies of different methods of co-registration in a phantom. The accuracy improved if co-registration was made from points or planes close to the area examined. The second study describes the accuracy of image-guided intervention on structures invisible to US but visible to CT or MRI. We measured a rate of success of biopsies in a phantom and found a rate of success, similar to that of conventional US-guided biopsy. In the third study, we found that the number of identifiable lesions by US increased by using the fusion-guided US, and the method was helpful as guidance for contrast-enhanced US (CEUS) as it enabled us to focus on a specific area. In the fourth study we computed a program to fuse a 3D-US dataset with a PET/CT examination. We have presented some of the first results on accuracy of real-time image fusion involving US and of the application of the method to patients with liver lesions.