A ló sziklacsontjának 3D-s összehasonlító megjelenítése

Abstract

SUMMARY Background: The petrosal bone is one of the smallest and most complex among the bones of the equine skull. Its irregular surface, several projections and channels, and hidden inner structures make its visualization challenging. Textbooks usually show this bone on different drawings and photographs, where the structures’ relationship and their spatial organization cannot be properly understood. Objectives: We wanted to create high-resolution surface models of certain petrosal bone structures in order to study them separately or in connection with the original one. Materials and methods: First we captured photos from a skull and its left petrosal bone. The isolated bone was scanned with a microfocus CT (FOV: 1024x1024, size of a voxel: 0.06 x 0.06 x 0.06 mm) and DICOM images were exported. Image volume was analysed with FEI Amira 6.0 for LifeSciences software; during segmentation individually labelled fields were generated to the following structures: surface model of the petrosal bone, malleus, incus, os lenticulare, stapes, inner ear and the channel of the facial nerve. 3-dimensional models were made from the label fields, and after refinement STL (stereolithography) models were made. Results and discussion: Changing the opacity of the surface models gave a unique possibility to compare the inner structure of the same bone seen on photographs and on the 3D-model in different aspects. Enlarging and labelling the inner ear and the auditory ossicles were also performed. In order to show the outer and the inner structure more interactively, three short video animations were created which present the outer aspects, the middle ear cavity, the inner ear and the channel of the facial nerve (like a virtual endoscopy). Finally, the STL model of the auditory ossicles associated with the inner ear was 3D-printed and colorized according to the surface models. In conclusion, the 3D-visualization (modelling, augmented and virtual reality, 3D-printing) can be an immense aid not only in the educational, but also in clinical and research fields.