Cochlear size variation in a large-scale international multicentre cohort
Abstract
AIM: This study aims to (1) review the literature on cochlear size, measured by the A-value, to assess reported variation across studies, and (2) consolidate cochlear parameters-specifically basal turn diameter (A-value) and width (B-value)-measured using the standardized DICOM viewer OTOPLAN®, and compare these with published data. METHODS: A scoping literature review was conducted using the search term "diameter of cochlear basal turn" to identify studies reporting A-value measurements. To complement this, cochlear measurements obtained with OTOPLAN® were collected from clinical collaborators across multiple international centres. The ratio of B- to A-values, which defines the cochlear basal turn shape, was calculated as previously described by Khurayzi et al. (2021). RESULTS: The literature review identified 38 studies comprising 5,206 A-value measurements (average: 9.08 mm; range: 8.01-10.03 mm). Additionally, 5,580 OTOPLAN® measurements were collected from 43 clinics across 25 countries (mean: 9.07 mm; range: 6.67-11.45 mm). Overall, 68.7% of cochleae exhibited an elliptical basal turn shape. CONCLUSION: Using a large, international multicentre dataset and a standardized measurement tool, this study demonstrates substantial variation in cochlear size and shape across clinical cohorts from different regions. The mean A-value (9.07 mm) is consistent with previously published literature, while the wider observed range highlights greater anatomical variability within a multicentre clinical population than previously reported. The majority of cochleae demonstrate an elliptical basal turn configuration.
Related
- Multicentre phase III randomised controlled trial to evaluate effectiveness of the Both EARS (BEARS) virtual reality training package to maximise hearing abilities in children and young people with bilateral cochlear implants: the BEARS protocol
- Methotrexate and Prednisolone compared to placebo and prednisolone in the treatment of severe Erythema Nodosum Leprosum: An international multicentre, double-blind randomised controlled clinical trial—MaPs in ENL
- Spatial hearing in adults with sequential bilateral cochlear implants: a longitudinal prospective cohort study
- Factors Associated With Parental Refusal of Pediatric Cochlear Implantation: A Retrospective Cohort Study
- The Association of Intra-Operative Steroid Administration on Hearing Threshold and Speech Perception Outcomes in Adult Cochlear Implant Recipients: A Retrospective Cohort Study.
BibTeX
@article{schreier2026cochlear,
title = {{Cochlear size variation in a large-scale international multicentre cohort}},
author = {Andrea Schreier and Mario Zernotti and Aanand Acharya and Robert Eisenberg and Maryam Sahwan and Mohamed Alshehabi and Vincent van Rompaey and Marc Lammers and Anandhan Dhanasingh and Suijun Chen and Lian Hui and Ahmed Mustafa and Nader El Feky and Ahmed Alshamsi and Ahmad Alamadi and Sebastian Schmerber and Benoît Godey and Estella Bilson-Amoah and Ramandeep Virk and Himanshu Swami and Abha Kumari and Shin-Ichi Usami and Hidekane Yoshimura and Grace Mwangi and Serah Ndegwa and Mutlaq Al-Sihan and Mariam Alkandari and Adekunle Adeyemo and Khalid Al Zaabi and Nasser Al Tamami and Piotr Henryk Skarzynski and Adam Walkowiak and Sima Sugarova and Vladislav Kuzovkov and Fida Almuhawas and Fahad Altamami and Cristina Alonso and Luis Lassaletta and Louis Hofmeyr and Mohamed Razwi Ismail Ahmed and Elnemarie Burden and Johan Grobbelaar and Shaban Mawala and Ali Jaffer and Amina Seguya and Linor Jones and Edward Flook and Anne Morgan Selleck and Camille Dunn and James Lin and Justus Müller-Goebel and Joachim Müller},
journal = {Hearing Research},
year = {2026},
month = oct,
doi = {10.1016/j.heares.2026.109708},
url = {https://univ-rennes.hal.science/hal-05825566v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Cochlear size variation in a large-scale international multicentre cohort
AU - Andrea Schreier
AU - Mario Zernotti
AU - Aanand Acharya
AU - Robert Eisenberg
AU - Maryam Sahwan
AU - Mohamed Alshehabi
AU - Vincent van Rompaey
AU - Marc Lammers
AU - Anandhan Dhanasingh
AU - Suijun Chen
AU - Lian Hui
AU - Ahmed Mustafa
AU - Nader El Feky
AU - Ahmed Alshamsi
AU - Ahmad Alamadi
AU - Sebastian Schmerber
AU - Benoît Godey
AU - Estella Bilson-Amoah
AU - Ramandeep Virk
AU - Himanshu Swami
AU - Abha Kumari
AU - Shin-Ichi Usami
AU - Hidekane Yoshimura
AU - Grace Mwangi
AU - Serah Ndegwa
AU - Mutlaq Al-Sihan
AU - Mariam Alkandari
AU - Adekunle Adeyemo
AU - Khalid Al Zaabi
AU - Nasser Al Tamami
AU - Piotr Henryk Skarzynski
AU - Adam Walkowiak
AU - Sima Sugarova
AU - Vladislav Kuzovkov
AU - Fida Almuhawas
AU - Fahad Altamami
AU - Cristina Alonso
AU - Luis Lassaletta
AU - Louis Hofmeyr
AU - Mohamed Razwi Ismail Ahmed
AU - Elnemarie Burden
AU - Johan Grobbelaar
AU - Shaban Mawala
AU - Ali Jaffer
AU - Amina Seguya
AU - Linor Jones
AU - Edward Flook
AU - Anne Morgan Selleck
AU - Camille Dunn
AU - James Lin
AU - Justus Müller-Goebel
AU - Joachim Müller
PY - 2026
DA - 2026/10/20
JO - Hearing Research
DO - 10.1016/j.heares.2026.109708
UR - https://univ-rennes.hal.science/hal-05825566v1
AB - AIM: This study aims to (1) review the literature on cochlear size, measured by the A-value, to assess reported variation across studies, and (2) consolidate cochlear parameters-specifically basal turn diameter (A-value) and width (B-value)-measured using the standardized DICOM viewer OTOPLAN®, and compare these with published data. METHODS: A scoping literature review was conducted using the search term "diameter of cochlear basal turn" to identify studies reporting A-value measurements. To complement this, cochlear measurements obtained with OTOPLAN® were collected from clinical collaborators across multiple international centres. The ratio of B- to A-values, which defines the cochlear basal turn shape, was calculated as previously described by Khurayzi et al. (2021). RESULTS: The literature review identified 38 studies comprising 5,206 A-value measurements (average: 9.08 mm; range: 8.01-10.03 mm). Additionally, 5,580 OTOPLAN® measurements were collected from 43 clinics across 25 countries (mean: 9.07 mm; range: 6.67-11.45 mm). Overall, 68.7% of cochleae exhibited an elliptical basal turn shape. CONCLUSION: Using a large, international multicentre dataset and a standardized measurement tool, this study demonstrates substantial variation in cochlear size and shape across clinical cohorts from different regions. The mean A-value (9.07 mm) is consistent with previously published literature, while the wider observed range highlights greater anatomical variability within a multicentre clinical population than previously reported. The majority of cochleae demonstrate an elliptical basal turn configuration.
SN - 0378-5955
SN - 1878-5891
ER -