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Bachelor's Thesis
Author of thesis: Terezie Vašutová
Acad. year: 2025/2026
Supervisor: Ing. Jan Šíma
Reviewer: Ing. Jiří Chmelík, Ph.D.
This bachelor’s thesis focuses on two closely related steps in the preoperative planning of cochlear implants: cochlear segmentation from CT scans and the subsequent determination of the cochlear duct length (CDL). The aim was, on the one hand, to compare the accuracy of three segmentation approaches (manual, semi-automatic, and automatic in OTOPLAN software) and, on the other hand, to implement and evaluate computational methods for estimating cochlear length. The analysis was performed on clinical data from 28 pediatric patients (53 ears). In the first part of the evaluation, spatial metrics demonstrated high agreement between manual and fully automatic segmentation (mean Dice coefficient 0.89; ASSD 0.15 mm). The second part of the study focused on the extraction of cochlear geometric parameters, the calculation of CDL using several mathematical models, and a comparison with the commercial OTOPLAN software. Statistical testing confirmed that while no significant differences were found between the automatic and semi-automatic methods for the basal spiral diameter (parameter A) and CDL determined by OTOPLAN software, the chosen method has a demonstrable effect on the results for other dimensions. The custom algorithms we implemented, which utilize principal component analysis (PCA) among other methods, showed that mathematical surface models predict different—and generally lower—length values than direct 3D measurements based on spatial trajectory. The results of this study demonstrate that automatic segmentation is a fast and reliable tool for clinical practice, while the determination of cochlear length remains sensitive to the measurement methodology used, the reference anatomical level, and the chosen mathematical model.
cochlea segmentation, cochlear implant, OTOPLAN, 3D Slicer, cochlear duct length, preoperative planning, pediatric patients
Date of defence
17.06.2026
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
Studentka prezentovala výsledky své práce a komise byla seznámena s posudky. Dr. Chmelík položil otázku navrhovala vaše metoda kratší nebo delší elektrodu oproti softwaru OTOPLAN. Dr. Šaclová položila otázku zda bude navržená metoda používána v nemocnici. Studentka obhájila bakalářskou práci a odpověděla na otázky členů komise a oponenta.
Language of thesis
Czech
Faculty
Fakulta elektrotechniky a komunikačních technologií
Department
Department of Biomedical Engineering
Study programme
Biomedical Technology and Bioinformatics (BPC-BTB)
Composition of Committee
prof. Ing. Martin Černý, Ph.D. (předseda) Ing. Helena Vítková, Ph.D. (místopředseda) MUDr. Michal Jurajda, Ph.D. (člen) Ing. Oto Janoušek, Ph.D. (člen) Ing. Jiří Chmelík, Ph.D. (člen) Ing. Lucie Šaclová, Ph.D. (člen)
Supervisor’s reportIng. Jan Šíma
Grade proposed by supervisor: A
Reviewer’s reportIng. Jiří Chmelík, Ph.D.
Grade proposed by reviewer: A
Responsibility: Mgr. et Mgr. Hana Odstrčilová