title: Three-dimensional localization of cochlear implant electrodes using epipolar stereophotogrammetry.
abstract: Three-dimensional (3-D) localization of individual cochlear implant electrodes within the inner ear is of importance for modeling the electrical field of the cochlea, designing the electrode array, and programming the associated speech processor. A 3-D reconstruction method of cochlear implant electrodes is proposed to localize individual electrodes from two X-ray views in combination with the spiral computed tomography technique. By adapting epipolar geometry to the configuration of an X-ray imaging system, we estimate individual electrode locations in the least square sense without using a patient attachment required by an existing stereophotogrammetry technique. Furthermore, our method does not require any knowledge of the intrinsic and extrinsic parameters of the imaging system. The performance of our method is studied in numerical simulation and with patient data and is found to be sufficiently accurate for clinical use. The maximum root mean-square errors measured are 0.0445 and 0.214 mm for numerical simulation and patient data, respectively.
authors.affiliation: Department of Medical Engineering, Center for Emergency Medical Informatics, Yonsei University College of Medicine, Seoul 120-752, Korea. sunkyoo@yumc.yonsei.ac.kr
authors.forename: Sun K
authors.initials: SK
authors.lastname: Yoo
authors.forename: Ge
authors.initials: G
authors.lastname: Wang
authors.forename: Fred
authors.initials: F
authors.lastname: Collison
authors.forename: Jay T
authors.initials: JT
authors.lastname: Rubinstein
authors.forename: Michael W
authors.initials: MW
authors.lastname: Vannier
authors.forename: Hee J
authors.initials: HJ
authors.lastname: Kim
authors.forename: Nam H
authors.initials: NH
authors.lastname: Kim
mesh_terms: D003051:Cochlea / Q000000981:diagnostic imaging* / Q000601:surgery*; D003054:Cochlear Implants; D004567:Electrodes, Implanted; D005240:Feasibility Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D010363:Pattern Recognition, Automated; D010780:Photogrammetry / Q000379:methods*; D019919:Prosthesis Implantation / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods*