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Noninvasive Technique for Monitoring Drug Transport Through the Murine Cochlea using Micro-Computed Tomography


Local delivery of drugs to the inner ear has the potential to treat inner ear disorders including permanent hearing loss or deafness. Current mathematical models describing the pharmacokinetics of drug delivery to the inner ear have been based on large rodent studies with invasive measurements of concentration at few locations within the cochlea. Hence, estimates of clearance and diffusion parameters are based on fitting measured data with limited spatial resolution to a model. To overcome these limitations, we developed a noninvasive imaging technique to monitor and characterize drug delivery inside the mouse cochlea using micro-computed tomography (μCT). To increase the measurement accuracy, we performed a subject-atlas image registration to exploit the information readily available in the atlas image of the mouse cochlea and pass segmentation or labeling information from the atlas to our μCT scans. The approach presented here has the potential to quantify concentrations at any point along fluid-filled scalae of the inner ear. This may permit determination of spatially dependent diffusion and clearance parameters for enhanced models.

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Micro-computed tomography


Auditory Brainstem Response


Artificial perilymph


Cochlear aqueduct


Compound Action Potential


Cerebrospinal fluid


Distortion product otoacoustic emissions


Intraperitoneal injection


Mouse cochlea database


Mutual information


Normalized mutual information


Outer diameter


Orthogonal plane fluorescence optical sectioning


Region of interest


Round window


Scala media


Statistical shape models


Scala tympani


Scala vestibuli




  1. Aljabar, P., R. A. Heckemann, A. Hammers, J. V. Hajnal, and D. Rueckert. Multi-atlas based segmentation of brain images: atlas selection and its effect on accuracy. Neuroimage 46(3):726–738, 2009.

    PubMed  Article  CAS  Google Scholar 

  2. Arnold, W., P. Senn, M. Hennig, C. Michaelis, K. Deingruber, R. Scheler, H. J. Steinhoff, F. Riphagen, and K. Lamm. Novel slow-and fast-type drug re lease round-window microimplants for local drug application to the cochlea: an experimental study in guinea pigs. Audiol. Neurootol. 10(1):53–63, 2005.

    PubMed  Article  CAS  Google Scholar 

  3. Badea, C. T., B. Fubara, L. W. Hedlund, and G. A. Johnson. 4-D micro-CT of the mouse heart. Mol. Imaging 4(2):110–116, 2005.

    PubMed  Google Scholar 

  4. Borkholder, D. A., X. Zhu, B. T. Hyatt, A. S. Archilla, W. J. Livingston, and R. D. Frisina. Murine intracochlear drug delivery: reducing concentration gradients within the cochlea. Hear. Res. 268(1):2–11, 2010.

    PubMed  Article  CAS  Google Scholar 

  5. Chen, Z., S. G. Kujawa, M. J. McKenna, J. O. Fiering, M. J. Mescher, J. T. Borenstein, E. E. Leary Swan, and W. F. Sewell. Inner ear drug delivery via a reciprocating perfusion system in the guinea pig. J. Control. Release 110(1):1–19, 2005.

    PubMed  Article  CAS  Google Scholar 

  6. Chen, Z., A. A. Mikulec, M. J. McKenna, W. F. Sewell, and S. G. Kujawa. A method for intracochlear drug delivery in the mouse. J. Neurosci. Methods 150(1): 67–73, 2006.

    PubMed  Article  CAS  Google Scholar 

  7. Conn, P. M. Sourcebook of Models for Biomedical Research. New Jersey: Humana Press, 2008.

  8. Dowsett, D. J., P. A. Kenny, and R. E. Johnston. The Physics of Diagnostic Imaging. London: Chapman & Hall Medical, 1998.

  9. Fischer, B., and J. Modersitzki. A unified approach to fast image registration and a new curvature based registration technique. Linear Algebra Appl 380:107–124, 2004.

    Article  Google Scholar 

  10. Gholipour, A., A. Akhondi-Asl, J. A. Estroff, and S. K. Warfield. Multi-atlas multi-shape segmentation of fetal brain MRI for volumetric and morphometric analysis of ventriculomegaly. NeuroImage 60(3):1819–1831, 2012.

    PubMed  Article  Google Scholar 

  11. Holden, M. A review of geometric transformations for nonrigid body registration. IEEE Trans. Med. Imaging 27(1):111–128, 2008.

    PubMed  Article  CAS  Google Scholar 

  12. Ibanez, L., W. Schroeder, L. Ng, and J. Cates. The ITK Software Guide. Clifton Park: Kitware Inc., 2005.

  13. Kim, H. W., Q. Y. Cai, H. Y. Jun, K. S. Chon, S. H. Park, S. J. Byun, M. S. Lee, J. M. Oh, H. S. Kim, and K. H. Yoon. Micro-CT imaging with a hepatocyte selective contrast agent for detecting liver metastasis in living mice. Acad. Radiol. 15(10):1282–1290, 2008.

    PubMed  Article  Google Scholar 

  14. King, E. B., A. N. Salt, H. T. Eastwood, and S. J. OLeary. Direct entry of gadolinium into the vestibule following intratympanic applications in guinea pigs and the influence of cochlear implantation. JARO J. Assoc. Res. Otolaryngol. 12(6):741–751, 2011.

    Article  CAS  Google Scholar 

  15. Klein, S., M. Staring, K. Murphy, M. A. Viergever, and J. Pluim. Elastix: a toolbox for intensity-based medical image registration. IEEE Trans. Med. Imaging 29(1):196–205, 2010.

    PubMed  Article  Google Scholar 

  16. Klein, S., U. A. van der Heide, I. M. Lips, M. van Vulpen, M. Staring, and J. P. W. Pluim. Automatic segmentation of the prostate in 3D MR images by atlas matching using localized mutual information. Med. Phys. 35(4):1407–1417, 2008.

    PubMed  Article  Google Scholar 

  17. Laurell, G., M. Teixeira, O. Sterkers, D. Bagger-Sjöbäck, S. Eksborg, O. Lidman, and E. Ferrary. Local administration of antioxidants to the inner ear: kinetics and distribution. Hear. Res. 173(1–2):198–209, 2002.

    PubMed  Article  CAS  Google Scholar 

  18. Maes, F., A. Collignon, D. Vandermeulen, G. Marchal, and P. Suetens. Multi modality image registration by maximization of mutual information. IEEE Trans. Med. Imaging 16(2):187–198, 1997.

    PubMed  Article  CAS  Google Scholar 

  19. McCall, A. A., E. E. L. Swan, J. T. Borenstein, W. F. Sewell, S. G. Kujawa, and M. J. McKenna. Drug delivery for treatment of inner ear disease: current state of knowledge. Ear Hear. 31(2):156–165, 2010.

    PubMed  Article  Google Scholar 

  20. Müller, M., R. Klinke, W. Arnold, and E. Oestreicher. Auditory nerve fibre responses to salicylate revisited. Hear. Res. 183(1):37–43, 2003.

    PubMed  Article  Google Scholar 

  21. Müller, M., K. von Hünerbein, S. Hoidis, and J. W. T. Smolders. A physio logical place–frequency map of the cochlea in the CBA/J mouse. Hear. Res. 202(1):63–73, 2005.

    PubMed  Article  Google Scholar 

  22. Mynatt, R., S. A. Hale, R. M. Gill, S. K. Plontke, and A. N. Salt. Demon stration of a longitudinal concentration gradient along scala tympani by sequential sampling of perilymph from the cochlear apex. JARO J. Assoc. Res. Otolaryngol. 7(2):182–193, 2006.

    Article  Google Scholar 

  23. Naganawa, S., Sone M., M. Yamazaki, H. Kawai, and T. Nakashima. Visualization of endolymphatic hydrops after intratympanic injection of Gd-DTPA: comparison of 2D and 3D real inversion recovery imaging. Magn. Reson. Med. Sci. 10(2):101–106, 2011.

    PubMed  Article  Google Scholar 

  24. Plontke, S. K., and A. N. Salt. Quantitative interpretation of corticosteroid pharmacokinetics in inner fluids using computer simulations. Hear. Res. 182(1–2):34–42, 2003.

    PubMed  Article  CAS  Google Scholar 

  25. Plontke, S. K., N. Siedow, R. Wegener, H. P. Zenner, and A. N. Salt. Cochlear pharmacokinetics with local inner ear drug delivery using a three-dimensional finite-element computer model. Audiol. Neurootol. 12(1):37–48, 2007.

    PubMed  Article  CAS  Google Scholar 

  26. Plontke, S. K., A. W. Wood, and A. N. Salt. Analysis of gentamicin kinetics in fluids of the inner ear with round window administration. Otol. Neurotol. 23(6):967–974, 2002.

    PubMed  Article  Google Scholar 

  27. Rohlfing, T., R. Brandt, R. Menzel, and C. R. Maurer. Evaluation of atlas selection strategies for atlas-based image segmentation with application to confocal microscopy images of bee brains. Neuroimage 21(4):1428–1442, 2004.

    PubMed  Article  Google Scholar 

  28. Salt, A. N. Simulation of methods for drug delivery to the cochlear fluids. Adv. Otorhinolaryngol. 59:140–148, 2002.

    PubMed  CAS  Google Scholar 

  29. Salt, A. N. Pharmacokinetics of drug entry into cochlear fluids. Volta Rev. 105(3):277, 2005.

    PubMed  Google Scholar 

  30. Salt, A. N., S. A. Hale, and S. K. Plontke. Perilymph sampling from the cochlear apex: a reliable method to obtain higher purity perilymph samples from scala tympani. J. Neurosci. Methods 153(1):121–129, 2006.

    PubMed  Article  CAS  Google Scholar 

  31. Salt, A. N., and Y. Ma. Quantification of solute entry into cochlear perilymph through the round window membrane. Hear. Res. 154(1–2):88–97, 2001.

    PubMed  Article  CAS  Google Scholar 

  32. Santi, P. A., I. Rapson, and A. Voie. Development of the mouse cochlea database (MCD). Hear. Res. 243(1–2):11–17, 2008.

    PubMed  Article  Google Scholar 

  33. Studholme, C., D. L. G. Hill, D. J. Hawkes. Automated 3D registration of MR and CT images of the head. Med. Image Anal. 1(2):163–175, 1996.

    PubMed  Article  CAS  Google Scholar 

  34. Studholme, C., D. L. G. Hill, and D. J. Hawkes. An overlap invariant entropy measure of 3D medical image alignment. Pattern Recogn. 32(1):71–86, 1999.

    Article  Google Scholar 

  35. Swan, E. E. L., M. J. Mescher, W. F. Sewell, S. L. Tao, and J. T. Borenstein. Inner ear drug delivery for auditory applications. Adv. Drug Deliv. Rev. 60(15):1583–1599, 2008.

    PubMed  Article  CAS  Google Scholar 

  36. Szymanski-Exner, A., N. T. Stowe, K. Salem, R. Lazebnik, J. R. Haaga, D. L. Wilson, and J. Gao. Noninvasive monitoring of local drug release using X-ray computed tomography: optimization and in vitro/in vivo validation. J. Pharm. Sci. 92(2):289–296, 2003.

    PubMed  Article  CAS  Google Scholar 

  37. Thevenaz, P., U. E. Ruttimann, and M. Unser. A pyramid approach to subpixel registration based on intensity. IEEE Trans. Image Process. 7(1):27–41, 1998.

    PubMed  Article  CAS  Google Scholar 

  38. Thorne, M., A. N. Salt, J. E. DeMott, M. M. Henson, O. W. Henson, and S. L. Gewalt. Cochlear fluid space dimensions for six species derived from reconstructions of three-dimensional magnetic resonance images. Laryngoscope 109(10):1661–1668, 1999.

    PubMed  Article  CAS  Google Scholar 

  39. Zheng, J., D. Jaffray, and C. Allen. Quantitative CT imaging of the spatial and temporal distribution of liposomes in a rabbit tumor model. Mol. Pharm. 6(2):571–580, 2009.

    PubMed  Article  CAS  Google Scholar 

  40. Zou, J., D. Poe, U. A. Ramadan, and I. Pyykkö. Oval window transport of Gd- DOTA from rat middle ear to vestibulum and scala vestibuli visualized by in vivo magnetic resonance imaging. Ann. Otol. Rhinol. Laryngol. 121(2):119–128, 2012.

    PubMed  Google Scholar 

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This work was supported in part by NIH Grants from the National Institute on Deafness and other Communication Disorders (K25-DC008291), the National Institute on Aging (P01 AG009524), and the Schmitt Foundation. We thank Dr. Peter Santi for providing access to the mouse cochlea data base. We also thank Mr. Mike Thullen for his technical support in μCT imaging. The help of Dr. Stefan Klein with the elastix software and the help of the AMIRA support team are gratefully acknowledged.

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Correspondence to David A. Borkholder.

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Associate Editor Aleksander S. Popel oversaw the review of this article.

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Haghpanahi, M., Gladstone, M.B., Zhu, X. et al. Noninvasive Technique for Monitoring Drug Transport Through the Murine Cochlea using Micro-Computed Tomography. Ann Biomed Eng 41, 2130–2142 (2013).

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  • Computed tomography
  • Image registration
  • Automatic segmentation
  • Drug delivery
  • Pharmacokinetics
  • Inner ear
  • Mouse
  • Cochlea