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On the accuracy of cochlear duct length measurement in computed tomographic images

  • Otology
  • Published:
European Archives of Oto-Rhino-Laryngology Aims and scope Submit manuscript

Abstract

Purpose

Patient specific selection of cochlear implants would benefit from pre-operative knowledge of cochlear length. Several methods for its measurement or estimation have been described in literature. This study focused on the achievable accuracy in clinically available imaging.

Methods

Five simplified cochlea models milled into porcine bone were scanned in water using clinical cone beam computed tomography. Due to their well-known dimensions these phantoms served as gold standard for the length measurements. Each phantom was measured ten times using the custom software Comet. In addition, cochleae in ten image datasets taken indiscriminately from clinical routine were measured ten times each to test the precision under realistic conditions. The results were also compared to estimations based on the diameter of the basal turn (A value) as described in literature.

Results

Measurement accuracy of the phantoms’ lengths was high (average error: − 0.2 mm; standard deviation: 0.3 mm). The pooled standard deviation for the measurements in clinical datasets was 0.6 mm. Errors resulted mainly from problems locating the helicotrema. The estimations differed on average − 1.7 to + 0.4 mm from the manual measurements and had standard deviations between 0.5 and 0.6 mm depending on the algorithm.

Conclusions

The program Comet was successfully used to accurately measure the length of the cochlea models in clinically available imaging. The lower image quality of patient scans reduced the precision of the measurement. Estimations using the A value are a quicker alternative for averagely sized cochleae in cases where the lack of accuracy is tolerable.

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References

  1. Roland PS, Wright CG (2006) Surgical aspects of cochlear implantation: mechanisms of insertional trauma. Adv Otorhinolaryngol 64:11–30. https://doi.org/10.1159/000094642

    PubMed  Google Scholar 

  2. Verberne J, Risi F, Campbell L, Chambers S, O’Leary S (2016) The effect of scala tympani morphology on basilar membrane contact with a straight electrode array. Otol Neurotol 38:47–53. https://doi.org/10.1097/MAO.0000000000001259

    Article  Google Scholar 

  3. Hardy M (1938) The length of the organ of Corti in man. Am J Anat 62:291–311. https://doi.org/10.1002/aja.1000620204

    Article  Google Scholar 

  4. Ulehlová L, Voldrich L, Janisch R (1987) Correlative study of sensory cell density and cochlear length in humans. Hear Res 28:149–151. https://doi.org/10.1016/0378-5955(87)90045-1

    Article  PubMed  Google Scholar 

  5. Adunka O, Unkelbach MH, Mack MG, Radeloff A, Gstoettner W (2005) Predicting basal cochlear length for electric-acoustic stimulation. Arch Otolaryngol Head Neck Surg 131:488–492. https://doi.org/10.1001/archotol.131.6.488

    Article  PubMed  Google Scholar 

  6. Würfel W, Lanfermann H, Lenarz T, Majdani O (2014) Cochlear length determination using cone beam computed tomography in a clinical setting. Hear Res 316:65–72. https://doi.org/10.1016/j.heares.2014.07.013

    Article  PubMed  Google Scholar 

  7. Johnston JDA, Scoffings D, Chung M, Baguley D, Donnelly NP, Axon PR, Gray RF, Tysome JR (2016) Computed tomography estimation of cochlear duct length can predict full insertion in cochlear implantation. Otol Neurotol 37:223–228. https://doi.org/10.1097/MAO.0000000000000955

    Article  PubMed  Google Scholar 

  8. Meng J, Li S, Zhang F, Li Q, Qin Z (2016) Cochlear size and shape variability and implications in cochlear implantation surgery. Otol Neurotol 37:1307–1313. https://doi.org/10.1097/MAO.0000000000001189

    Article  PubMed  Google Scholar 

  9. Mistrík P, Jolly C (2016) Optimal electrode length to match patient specific cochlear anatomy. Eur Ann Otorhinolaryngol Head Neck Dis 133:S68–S71. https://doi.org/10.1016/j.anorl.2016.05.001

    Article  PubMed  Google Scholar 

  10. Koch RW, Elfarnawany M, Zhu N, Ladak HM, Agrawal SK (2017) Evaluation of cochlear duct length computations using synchrotron radiation phase-contrast imaging. Otol Neurotol 38:1. https://doi.org/10.1097/MAO.0000000000001410

    Article  Google Scholar 

  11. Lexow GJ, Rau TS, Gellrich N-C, Lenarz T, Majdani O (2015) Cochlea-Längenmessung in rotierenden, midmodiolaren Schichtansichten—Darstellung der Methode. In: Hahn HK, Kikinis R, Klein J et al (eds) Proc. 14. Jahrestagung der Deutschen Gesellschaft für Computer- und Roboterassistierte Chirurgie (CURAC). Fraunhofer MEVIS, Bremen, pp 335–336

    Google Scholar 

  12. Lexow GJ, Schurzig D, Gellrich N-C, Lenarz T, Majdani O, Rau TS (2016) Visualization, measurement and modelling of the cochlea using rotating midmodiolar slice planes. Int J Comput Assist Radiol Surg. https://doi.org/10.1007/s11548-016-1374-7

    Google Scholar 

  13. Van Wermeskerken GKA, Prokop M, Van Olphen AF, Albers FWJ (2007) Intracochlear assessment of electrode position after cochlear implant surgery by means of multislice computer tomography. Eur Arch Otorhinolaryngol 264:1405–1407. https://doi.org/10.1007/s00405-007-0389-7

    Article  PubMed  Google Scholar 

  14. Lecerf P, Bakhos D, Cottier J-P, Lescanne E, Trijolet JP, Robier A (2011) Midmodiolar reconstruction as a valuable tool to determine the exact position of the cochlear implant electrode array. Otol Neurotol 32:1075–1081. https://doi.org/10.1097/MAO.0b013e318229d4dd

    Article  PubMed  Google Scholar 

  15. Malherbe TK, Hanekom T, Hanekom JJ (2016) Constructing a three-dimensional electrical model of a living cochlear implant user’s cochlea. Int J Numer Method Biomed Eng 32:e02751. https://doi.org/10.1002/cnm.2751

    Article  Google Scholar 

  16. Escudé B, James C, Deguine O, Cochard N, Eter E, Fraysse B (2006) The size of the cochlea and predictions of insertion depth angles for cochlear implant electrodes. Audiol Neurotol 11:27–33. https://doi.org/10.1159/000095611

    Article  Google Scholar 

  17. Alexiades G, Dhanasingh A, Jolly C (2015) Method to estimate the complete and two-turn cochlear duct length. Otol Neurotol 36:904–907. https://doi.org/10.1097/MAO.0000000000000620

    Article  PubMed  Google Scholar 

  18. Avci E, Nauwelaers T, Lenarz T, Hamacher V, Kral A (2014) Variations in microanatomy of the human cochlea. J Comp Neurol 522:3245–3261. https://doi.org/10.1002/cne.23594

    Article  PubMed  PubMed Central  Google Scholar 

  19. Verbist BM, Skinner MW, Cohen LT, Leake PA, James C, Boëx C, Holden TA, Finley CC, Roland PS, Roland JT, Haller M, Patrick JF, Jolly CN, Faltys MA, Briaire JJ, Frijns JHM (2010) Consensus panel on a cochlear coordinate system applicable in histologic, physiologic, and radiologic studies of the human cochlea. Otol Neurotol 31:722–730. https://doi.org/10.1097/MAO.0b013e3181d279e0

    Article  PubMed  PubMed Central  Google Scholar 

  20. Advanced Bionics (2005) HiRes90k Surgeon’s Manual. https://www.advancedbionics.com/content/dam/advancedbionics/Documents/libraries/Audiologists-&-Surgeons-Library/Surgical-Manuals-&-Catalogs/hires-90k-surgeons-manual-hifocus-helix-1j.pdf. Accessed 19 Feb 2018

  21. MED-EL (2013) Electrode arrays: designed for atraumatic implantation providing superior hearing performance. http://www.medel.com/data/pdf/21617.pdf. Accessed 19 Feb 2018

  22. Cochlear (2014) Cochlear Nucleus CI422 with Slim Straight - Technical Specifications. http://www.cochlear.com/wps/wcm/connect/e9bc4ab6-8b75-4cf4-bcda-fb7b2757efbb/FUN1356+ISS2+MAR14+CI422+Specifications+3.pdf?MOD=AJPERES. Accessed 19 Feb 2018

  23. Martinez-Monedero R, Niparko JK, Aygun N (2011) Cochlear coiling pattern and orientation differences in cochlear implant candidates. Otol Neurotol 32:1086–1093. https://doi.org/10.1097/MAO.0b013e31822a1ee2

    Article  PubMed  Google Scholar 

  24. Erixon E, Rask-Andersen H (2013) How to predict cochlear length before cochlear implantation surgery. Acta Otolaryngol 133:1258–1265. https://doi.org/10.3109/00016489.2013.831475

    Article  PubMed  Google Scholar 

  25. Yoo SK, Wang G, Rubinstein JT, Vannier MW (2000) Three-dimensional geometric modeling of the cochlea using helico-spiral approximation. IEEE Trans Biomed Eng 47:1392–1402. https://doi.org/10.1109/10.871413

    Article  CAS  PubMed  Google Scholar 

  26. Rivas A, Cakir A, Hunter JB, Labadie RF, Zuniga MG, Wanna GB, Dawant BM, Noble JH (2017) Automatic cochlear duct length estimation for selection of cochlear implant electrode arrays. Otol Neurotol 38:339–346. https://doi.org/10.1097/MAO.0000000000001329

    Article  PubMed  PubMed Central  Google Scholar 

  27. Franke-Trieger A, Mürbe D (2015) Estimation of insertion depth angle based on cochlea diameter and linear insertion depth: a prediction tool for the CI422. Eur Arch Otorhinolaryngol 272:3193–3199. https://doi.org/10.1007/s00405-014-3352-4

    Article  PubMed  Google Scholar 

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Acknowledgements

The presented work was supported by the German Research Foundation (DFG) through the cluster of excellence “Hearing4all” EXC 1077/1 and by the German Federal Ministry of Education and Research (BMBF, FKZ 13GW0019E). Responsibility for the contents of this publication lies with the authors.

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Authors and Affiliations

  1. Department of Otolaryngology and Cluster of Excellence “Hearing4all” EXC 1077/1, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hanover, Germany

    G. Jakob Lexow, Marcel Kluge, Thomas Lenarz, Omid Majdani & Thomas S. Rau

  2. Department of Craniomaxillofacial Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hanover, Germany

    Nils-Claudius Gellrich

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  1. G. Jakob Lexow
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  2. Marcel Kluge
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  4. Thomas Lenarz
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  5. Omid Majdani
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  6. Thomas S. Rau
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Correspondence to G. Jakob Lexow.

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G. Jakob Lexow, Marcel Kluge, Nils-Claudius Gellrich, Thomas Lenarz, Omid Majdani and Thomas S. Rau declare that they have no conflict of interest.

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This article does not contain any studies with human participants or animals performed by any of the authors.

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Lexow, G.J., Kluge, M., Gellrich, NC. et al. On the accuracy of cochlear duct length measurement in computed tomographic images. Eur Arch Otorhinolaryngol 275, 1077–1085 (2018). https://doi.org/10.1007/s00405-018-4930-7

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  • DOI: https://doi.org/10.1007/s00405-018-4930-7

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