Characterization of the human helicotrema: implications for cochlear duct length and frequency mapping
Abstract Background Despite significant anatomical variation amongst patients, cochlear implant frequency-mapping has traditionally followed a patient-independent approach. Basilar membrane (BM) length is required for patient-specific frequency-mapping, however cochlear duct length (CDL) measurement...
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SAGE Publishing
2020-01-01
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| Series: | Journal of Otolaryngology - Head and Neck Surgery |
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| Online Access: | https://doi.org/10.1186/s40463-019-0398-8 |
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| author | Luke Helpard Hao Li Helge Rask-Andersen Hanif M. Ladak Sumit K. Agrawal |
| author_facet | Luke Helpard Hao Li Helge Rask-Andersen Hanif M. Ladak Sumit K. Agrawal |
| author_sort | Luke Helpard |
| collection | DOAJ |
| description | Abstract Background Despite significant anatomical variation amongst patients, cochlear implant frequency-mapping has traditionally followed a patient-independent approach. Basilar membrane (BM) length is required for patient-specific frequency-mapping, however cochlear duct length (CDL) measurements generally extend to the apical tip of the entire cochlea or have no clearly defined end-point. By characterizing the length between the end of the BM and the apical tip of the entire cochlea (helicotrema length), current CDL models can be corrected to obtain the appropriate BM length. Synchrotron radiation phase-contrast imaging has made this analysis possible due to the soft-tissue contrast through the entire cochlear apex. Methods Helicotrema linear length and helicotrema angular length measurements were performed on synchrotron radiation phase-contrast imaging data of 14 cadaveric human cochleae. On a sub-set of six samples, the CDL to the apical tip of the entire cochlea (CDLTIP) and the BM length (CDLBM) were determined. Regression analysis was performed to assess the relationship between CDLTIP and CDLBM. Results The mean helicotrema linear length and helicotrema angular length values were 1.6 ± 0.9 mm and 67.8 ± 37.9 degrees, respectively. Regression analysis revealed the following relationship between CDLTIP and CDLBM: CDLBM = 0.88(CDLTIP) + 3.71 (R 2 = 0.995). Conclusion This is the first known study to characterize the length of the helicotrema in the context of CDL measurements. It was determined that the distance between the end of the BM and the tip of the entire cochlea is clinically consequential. A relationship was determined that can predict the BM length of an individual patient based on their respective CDL measured to the apical tip of the cochlea. |
| format | Article |
| id | doaj-art-8d9bcde4acd349808d14f82af44c4bef |
| institution | Kabale University |
| issn | 1916-0216 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | SAGE Publishing |
| record_format | Article |
| series | Journal of Otolaryngology - Head and Neck Surgery |
| spelling | doaj-art-8d9bcde4acd349808d14f82af44c4bef2025-08-20T03:37:56ZengSAGE PublishingJournal of Otolaryngology - Head and Neck Surgery1916-02162020-01-014911710.1186/s40463-019-0398-8Characterization of the human helicotrema: implications for cochlear duct length and frequency mappingLuke Helpard0Hao Li1Helge Rask-Andersen2Hanif M. Ladak3Sumit K. Agrawal4School of Biomedical Engineering, Western UniversityDepartment of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University HospitalDepartment of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University HospitalSchool of Biomedical Engineering, Western UniversitySchool of Biomedical Engineering, Western UniversityAbstract Background Despite significant anatomical variation amongst patients, cochlear implant frequency-mapping has traditionally followed a patient-independent approach. Basilar membrane (BM) length is required for patient-specific frequency-mapping, however cochlear duct length (CDL) measurements generally extend to the apical tip of the entire cochlea or have no clearly defined end-point. By characterizing the length between the end of the BM and the apical tip of the entire cochlea (helicotrema length), current CDL models can be corrected to obtain the appropriate BM length. Synchrotron radiation phase-contrast imaging has made this analysis possible due to the soft-tissue contrast through the entire cochlear apex. Methods Helicotrema linear length and helicotrema angular length measurements were performed on synchrotron radiation phase-contrast imaging data of 14 cadaveric human cochleae. On a sub-set of six samples, the CDL to the apical tip of the entire cochlea (CDLTIP) and the BM length (CDLBM) were determined. Regression analysis was performed to assess the relationship between CDLTIP and CDLBM. Results The mean helicotrema linear length and helicotrema angular length values were 1.6 ± 0.9 mm and 67.8 ± 37.9 degrees, respectively. Regression analysis revealed the following relationship between CDLTIP and CDLBM: CDLBM = 0.88(CDLTIP) + 3.71 (R 2 = 0.995). Conclusion This is the first known study to characterize the length of the helicotrema in the context of CDL measurements. It was determined that the distance between the end of the BM and the tip of the entire cochlea is clinically consequential. A relationship was determined that can predict the BM length of an individual patient based on their respective CDL measured to the apical tip of the cochlea.https://doi.org/10.1186/s40463-019-0398-8HelicotremaHelicotrema sizeCochlear duct lengthBasilar membraneCochlear apexCochlear implant |
| spellingShingle | Luke Helpard Hao Li Helge Rask-Andersen Hanif M. Ladak Sumit K. Agrawal Characterization of the human helicotrema: implications for cochlear duct length and frequency mapping Journal of Otolaryngology - Head and Neck Surgery Helicotrema Helicotrema size Cochlear duct length Basilar membrane Cochlear apex Cochlear implant |
| title | Characterization of the human helicotrema: implications for cochlear duct length and frequency mapping |
| title_full | Characterization of the human helicotrema: implications for cochlear duct length and frequency mapping |
| title_fullStr | Characterization of the human helicotrema: implications for cochlear duct length and frequency mapping |
| title_full_unstemmed | Characterization of the human helicotrema: implications for cochlear duct length and frequency mapping |
| title_short | Characterization of the human helicotrema: implications for cochlear duct length and frequency mapping |
| title_sort | characterization of the human helicotrema implications for cochlear duct length and frequency mapping |
| topic | Helicotrema Helicotrema size Cochlear duct length Basilar membrane Cochlear apex Cochlear implant |
| url | https://doi.org/10.1186/s40463-019-0398-8 |
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