Application of monomodal intensity-based medical image registration on brain tumor growthiness investigation

The process of aligning two medical images (MR/MR, MR/CT, MR/PET, CT/PET etc.) and taking those medical images to the same coordinate system is called medical image registration. The images can be acquired with different sensors (MR, CT, PET, SPECT etc.) at the same time or with the same sensor at the different times. Registration concept is one of the most important and popular aspect of digital image processing. Thanks to using suitable computer programming techniques and transformation between two images a new much more informative image can be found. In this thesis, monomodal registration of MR image of a patient with brain tumor with another MR image of the same patient at a different time is proposed so that the growthiness of the tumor inside the brain can be investigated. Registration is carried out using intensity based technique and Sum of Squared Differences (SSD) metric with the regular step gradient descent optimizer. The advantage of this method is that there is no need to calculate image features such as Fourier transform, eigenvalues and eigenvectors. This technique is superior to other techniques such as cross-correlation method and mutual information similarity measures because it avoids the wrong registration and uses less computation.