title: Reconstruction of muscle fascicle architecture from iodine-enhanced microCT images: A combined texture mapping and streamline approach.
abstract: Skeletal muscle models are used to investigate motion and force generation in both biological and bioengineering research. Yet, they often lack a realistic representation of the muscle's internal architecture which is primarily composed of muscle fibre bundles, known as fascicles. Recently, it has been shown that fascicles can be resolved with micro-computed tomography (µCT) following staining of the muscle tissue with iodine potassium iodide (I2KI). Here, we present the reconstruction of the fascicular spatial arrangement and geometry of the superficial masseter muscle of a dog based on a combination of pattern recognition and streamline computation. A cadaveric head of a dog was incubated in I2KI and µCT-scanned. Following segmentation of the masseter muscle a statistical pattern recognition algorithm was applied to create a vector field of fascicle directions. Streamlines were then used to transform the vector field into a realistic muscle fascicle representation. The lengths of the reconstructed fascicles and the pennation angles in two planes (frontal and sagittal) were extracted and compared against a tracked fascicle field obtained through cadaver dissection. Both fascicle lengths and angles were found to vary substantially within the muscle confirming the complex and heterogeneous nature of skeletal muscle described by previous studies. While there were significant differences in the pennation angle between the experimentally derived and µCT-reconstructed data, there was congruence in the fascicle lengths. We conclude that the presented approach allows for embedding realistic fascicle information into finite element models of skeletal muscles to better understand the functioning of the musculoskeletal system.
authors.affiliation: Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Leipzig, Germany; Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Institute of Systematic Zoology and Evolutionary Biology with Phyletic Museum, Friedrich-Schiller-University Jena, Jena, Germany. Electronic address: kornelius_kupczik@eva.mpg.de.
authors.forename: Kornelius
authors.initials: K
authors.lastname: Kupczik
authors.affiliation: Institute of Systematic Zoology and Evolutionary Biology with Phyletic Museum, Friedrich-Schiller-University Jena, Jena, Germany; Department of Bioinformatics, Friedrich-Schiller-University Jena, Jena, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Stark
authors.affiliation: Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
authors.forename: Roger
authors.initials: R
authors.lastname: Mundry
authors.affiliation: Stuttgart Research Centre for Simulation Technology (SimTech), Universität Stuttgart, Stuttgart, Germany.
authors.forename: Fabian T
authors.initials: FT
authors.lastname: Neininger
authors.affiliation: Stuttgart Research Centre for Simulation Technology (SimTech), Universität Stuttgart, Stuttgart, Germany; Institute of Applied Mechanics (CE), Chair of Continuum Mechanics, Universität Stuttgart, Stuttgart, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Heidlauf
authors.affiliation: Stuttgart Research Centre for Simulation Technology (SimTech), Universität Stuttgart, Stuttgart, Germany; Institute of Applied Mechanics (CE), Chair of Continuum Mechanics, Universität Stuttgart, Stuttgart, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Röhrle
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D005260:Female; D007091:Image Processing, Computer-Assisted; D007455:Iodine / Q000737:chemistry*; D008406:Masseter Muscle / Q000000981:diagnostic imaging; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000502:physiology; D012886:Skull / Q000000981:diagnostic imaging; D013194:Staining and Labeling; D055114:X-Ray Microtomography
chemical_list: D007455:Iodine
keywords: Dog; Iodine potassium iodide; Masseter muscle; Muscle modelling; Pennation angle