Cochlear shape description and analyzing via medial models

ABSTRACT Planning and analyzing of surgical interventions are often based on computer models derived from computedtomography images of the patient. In the eld of cochlear implant insertion the modeling of several structures ofthe inner ear is needed. One structure is the overall helical shape of the cochlea itself. In this paper we analyzethe cochlea by applying statistical shape models with medial representation. The cochlea is considered as tubularstructure. A model representing the skeleton of training data and an atomic composition of the structure is built.We reduce the representation to a linear chain of atoms. As result a compact discrete model is possible. It isdemonstrated how to place the atoms and build up their correspondence through a population of training data.The outcome of the applied representation is discussed in terms of impact on automated segmentation algorithmsand known advantages of medial models are revisited.Keywords: inner ear, segmentation, active shape models, cochlea