H. Siegfried Stiehl

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We consider elastic image registration based on a set of corresponding anatomical point landmarks and approximating thin-plate splines. This approach is an extension of the original interpolating thin-plate spline approach and allows to take into account landmark localization errors. The extension is important for clinical applications since landmark(More)
Common elastic registration schemes based on landmarks and radial basis functions (RBFs) such as thin-plate splines or multiquadrics are global. Here, we introduce radial basis functions with compact support for elastic registration of medical images which have an improved locality, i.e. which allow to constrain elastic deformations to image parts where(More)
The accuracy of image-guided neurosurgery generally suffers from brain deformations due to intraoperative changes. These deformations cause significant changes of the anatomical geometry (organ shape and spatial interorgan relations), thus making intraoperative navigation based on preoperative images error prone. In order to improve the navigation accuracy,(More)
Point-based registration of images strongly depends on the extraction of suitable landmarks. Recently, different 3D operators have been proposed in the literature for the detection of anatomical point landmarks in 3D images. In this paper, we investigate nine 3D differential operators for the detection of point landmarks in 3D MR and CT images. These(More)
We consider elastic registration of medical image data based on thin plate splines using a set of corresponding anatomical point land marks Previous work on this topic has concentrated on using interpola tion schemes Such schemes force the corresponding landmarks to exactly match each other and assume that the landmark positions are known exactly However in(More)
Neuronavigation systems are now an important component of many modern neurosurgical treatment strategies. Their support facilities intraoperative orientation and makes neurosurgical operations more precise and less traumatic. Computer-aided neurosurgery is definitively not a temporary fashionable phenomenon, the concept of neuronavigation is here to stay.(More)
A parameter-free approach for non-rigid image registration based on elasticity theory is presented. In contrast to traditional physically-based numerical registration methods, no forces have to be computed from image data to drive the elastic deformation. Instead, displacements obtained with the help of mapping boundary structures in the source and target(More)
We introduce radial basis functions with compact support for elastic registration of medical images. With these basis functions the influence of a landmark on the registration result is limited to a circle in 2D and, respectively, to a sphere in 3D. Therefore, the registration can be locally constrained which especially allows to deal with rather local(More)
In order to improve the accuracy of image-guided neurosurgery, different biomechanical models have been developed to correct preoperative images with respect to intraoperative changes like brain shift or tumor resection. All existing biomechanical models simulate different anatomical structures by using either appropriate boundary conditions or by spatially(More)