Optimization of 3D-Visualization of Micro-Anatomical Structures of the Human Inner Ear in Osmium Tetroxide Contrast Enhanced Micro-CT Scans

Introduction: Knowledge of the neuro-anatomical architecture of the inner ear contributes to the improvement and development of cochlear and vestibular implants. The present knowledge is mainly based on two-dimensional images (histology) or derived models that simplify the complexity of this architecture. This study investigated the feasibility of visualizing relevant neuro-anatomical structures of the inner ear in a dynamic three-dimensional reproduction, using a combination of staining, micro-CT imaging and an image processing algorithm. Methods: Four fresh cadaveric temporal bones were postfixed with osmium tetroxide (OsO4) and decalcified with EDTA. Micro-CT was used for scanning at 10 μm (4 scans) and 5.5 μm (1 scan) voxel resolution. A new image processing algorithm was developed and the scans were visualized in open source software. Results: OsO4 enhanced the contrast in all scans and the visualization was substantially improved by the image processing algorithm. The three-dimensional renderings provided detailed visualization of the whole inner ear. Details were visible up to the size of individual neurons, nerve crossings and the specific neuro-anatomical structures such as the tunnel of Corti. Conclusion: The combination of OsO4, micro-CT and the proposed image processing algorithm provides an accurate and detailed visualization of the three-dimensional micro-anatomy of the human inner ear.

[1]  R. Illing,et al.  The human round window – a perilymph pressure regulator?On a novel mechanoreceptor‐like neuron in the human round window membrane , 2004 .

[2]  M. Lévêque,et al.  An anatomical study of the vestibulocochlear anastomosis (anastomosis of Oort) in humans: preliminary results , 2005, Surgical and Radiologic Anatomy.

[3]  Johannes E. Schindelin,et al.  Fiji: an open-source platform for biological-image analysis , 2012, Nature Methods.

[4]  Michael J. Todd,et al.  A Mathematical Model of Human Semicircular Canal Geometry: A New Basis for Interpreting Vestibular Physiology , 2010, Journal of the Association for Research in Otolaryngology.

[5]  Prabhakar Rajiah,et al.  Artifacts at Cardiac CT: Physics and Solutions. , 2016, Radiographics : a review publication of the Radiological Society of North America, Inc.

[6]  Silvestro Micera,et al.  Electrical Potential Distribution within the Inner Ear: A preliminary study for vestibular prosthesis design , 2012, 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[7]  R. K. Kalkman,et al.  Stimulation strategies and electrode design in computational models of the electrically stimulated cochlea: An overview of existing literature , 2016, Network.

[8]  A. R. D. Chicchis,et al.  Handbook of Mouse Auditory Research: From Behavior to Molecular Biology , 2002 .

[9]  De-liang Huang,et al.  The topographical relationships and anastomosis of the nerves in the human internal auditory canal , 2008, Surgical and Radiologic Anatomy.

[10]  Manuel Dierick,et al.  MicroCT versus sTSLIM 3D Imaging of the Mouse Cochlea , 2013, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[11]  G. L. Rasmussen.  The olivary peduncle and other fiber projections of the superior olivary complex , 1946, The Journal of comparative neurology.

[12]  Peter Damberg,et al.  Experimental Fusion of Contrast Enhanced High-Field Magnetic Resonance Imaging and High-Resolution Micro-Computed Tomography in Imaging the Mouse Inner Ear , 2015, The open neuroimaging journal.

[13]  B. Ruthensteiner,et al.  A correlative approach for combining microCT, light and transmission electron microscopy in a single 3D scenario , 2013, Frontiers in Zoology.

[14]  I. Winter,et al.  The effect of vestibular nerve section upon tinnitus. , 2002, Clinical otolaryngology and allied sciences.

[15]  Jay T Rubinstein,et al.  Music perception in cochlear implant users and its relationship with psychophysical capabilities. , 2008, Journal of rehabilitation research and development.

[16]  F. Boas,et al.  CT artifacts: Causes and reduction techniques , 2012 .

[17]  B. Metscher.  MicroCT for comparative morphology: simple staining methods allow high-contrast 3D imaging of diverse non-mineralized animal tissues , 2009, BMC Physiology.

[18]  Lindeman Hh.  Studies on the morphology of the sensory regions of the vestibular apparatus with 45 figures. , 1969 .

[19]  P. L. Albernaz,et al.  History of cochlear implants , 2014, Brazilian journal of otorhinolaryngology.

[20]  Milan Sonka,et al.  3D Slicer as an image computing platform for the Quantitative Imaging Network. , 2012, Magnetic resonance imaging.

[21]  James M Gaylor,et al.  Effectiveness of Cochlear Implants in Adults with Sensorineural Hearing Loss , 2011 .

[22]  R. Ciuman.  The Efferent System or Olivocochlear Function Bundle – Fine Regulator and Protector of Hearing Perception , 2010, International journal of biomedical science : IJBS.

[23]  E. A. Williams,et al.  Effects of olivocochlear bundle section on otoacoustic emissions in humans: efferent effects in comparison with control subjects. , 1994, Acta oto-laryngologica.

[24]  Clemens Zierhofer,et al.  Frequency-place map for electrical stimulation in cochlear implants: Change over time , 2015, Hearing Research.

[25]  Raymond van de Berg,et al.  The Vestibular Implant: Quo Vadis? , 2011, Front. Neur..

[26]  B. J. Moxham,et al.  The legal and ethical framework governing Body Donation in EuropeA review of current practice and recommendations for good practice , 2008 .

[27]  W Freysinger,et al.  High‐resolution X‐ray tomography of the human inner ear: synchrotron radiation‐based study of nerve fibre bundles, membranes and ganglion cells , 2009, Journal of microscopy.

[28]  U Vogel,et al.  New Approach for 3D Imaging and Geometry Modeling of the Human Inner Ear , 1999, ORL.

[29]  José L Bueno-López,et al.  The legal and ethical framework governing Body Donation in Europe - 1st update on current practice , 2012 .

[30]  R Mark Henkelman,et al.  Diffusible iodine‐based contrast‐enhanced computed tomography (diceCT): an emerging tool for rapid, high‐resolution, 3‐D imaging of metazoan soft tissues , 2016, Journal of anatomy.

[31]  Thomas Zahnert,et al.  The creation of geometric three-dimensional models of the inner ear based on micro computer tomography data , 2008, Hearing Research.

[32]  A. Geers,et al.  Spoken Language Benefits of Extending Cochlear Implant Candidacy Below 12 Months of Age , 2013, Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology.

[33]  Frank Böhnke,et al.  Three-dimensional representation of the human cochlea using micro-computed tomography data: Presenting an anatomical model for further numerical calculations , 2012, Acta oto-laryngologica.