Association of Relevant Anatomic Contours of Ultrasound and MRI Images by Optimisation via Different Geometric Parameters

We focus on the simultaneous analysis and harmonisation of 2D dynamic ultrasound and MRI records, the aim of which is to find a biunique correspondence between the radial geometry of the ultrasound frames and the rectangular geometry of the MRI frames. One possible way of adjusting the two sources is the bidirectional conversion of the relevant anatomic contours of the oral cavity. We implemented this idea by the construction of special geometric transformations acting on the tongue and palate contours fitted automatically to the boundaries of the different tissues visualised by the ultrasound and MRI images. The transformations include the magnification and rotation of the curves, determining a given set of parameters. We create such optimisation techniques with which the average distance between the corresponding ultrasound and MRI contours can be minimised fixed by the most favourable values of the parameter set defined by the geometric transformations. By executing these operations, the ultrasound contours can be projected onto the MRI frames, and vice versa. We validate our results by visual and numerical considerations, as well.