Registration approaches for the optimisation of medical diagnostics and treatment

Many medical diagnostics and treatment procedures in the oncology, cranio-maxillofacial surgery, radiotherapy and neurosurgery deal with volumetric as well as surface data. Tumor detection or generation of the virtual treatment scene involves using complementary data sets that are obtained from different sensors, for example MR and CT data, or by the same sensor at different epochs. The very need for registration arises from the fact that the complementary data sets are acquired by imaging devices using different spatial coordinate systems or/and the anatomically correct superposition of two data instances cannot be performed without locally applied elastic transformation. The volume or surface matching is therefore an essential task in these applications. From the mathematical point of view the data aligning problem is an optimization task, which can be solved by using deterministic or non-deterministic optimization algorithms. Depending on the data size and the complexity of required matching transformation the runtime behaviour of the registration methods can stretch out between real-time and many hours' computations. In this paper various applications of the same registration paradigm are presented and discussed. The wide spectrum of the medical applications shows the importance of the registration approach for the optimization of medical diagnostics and treatment.