Intra- and multi-modality registration and fusion of body images in radiology
Date of Award
Doctor of Philosophy (Ph.D.)
First Committee Member
Joachim H. Nagel, Committee Chair
The availability of methods to register multimodality images in order to "fuse" them and to correlate their information is increasingly becoming a requirement for various diagnostic and therapeutic procedures. A variety of image registration methods have been developed but they remain limited to specific clinical applications.Assuming rigid body transformation, two images can be registered if their differences are calculated in terms of translation, rotation and scaling. The difficulty lies in the fact that these parameters are coupled together and cannot be computed simultaneously. This dissertation describes the development and testing of a new correlation based approach for three-dimensional image registration. First, the scaling factors introduced by the imaging devices are calculated and compensated for. Then, the two images become translation invariant by computing their three-dimensional Fourier magnitude spectra. Subsequently, cartesian to spherical transformation is performed and then the three-dimensional rotation is computed using one of two methods: spherical belts or polar shells. The method of spherical belts maps the three angles into cyclic shifts of one-dimensional orthogonal functions and proceeds iteratively to calculate them. The method of polar shells maps the three angles into one rotation and two translations of a two-dimensional function and calculates them directly. A basic assumption for both methods is that the three-dimensional rotation is constrained to one large and two relatively small angles. This assumption is valid for body imaging in a clinical setting where the patient lies restricted on an imaging table.The new three-dimensional image registration method was tested with simulations using computer generated phantom data as well as actual clinical data. Performance analysis and accuracy evaluation of the method using simulations yielded error in the sub-pixel range.
Engineering, Biomedical; Health Sciences, Radiology
Georgiou, Michalakis Flourentzos, "Intra- and multi-modality registration and fusion of body images in radiology" (1997). Dissertations from ProQuest. 3443.