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Abstract Objectives This study aimed to qualitatively evaluate the variations in nerve bundles between patients with normal anatomy and those with inner‐ear anomalies. Methods Magnetic resonance imaging (MRI) scans of the temporal bones of candidates for cochlear implants (CIs) enrolled at a tertiary center were retrospectively reviewed from the clinical database. The 3.0‐Tesla MRI scans were analyzed using a three‐dimensional slicer to visualize the nerve bundles in the internal auditory canal. Results A total of 49 ears were analyzed. Twenty ears exhibited normal inner ear anatomy, whereas 29 ears had various inner‐ear malformations. The cochlear nerve (CN) was visible on all 20 scans with normal inner‐ear anatomy. In addition, the CN was visualized in 18 scans with inner ear malformations. Furthermore, the CN was identified in six of the eight scans with IP type I, whereas in two scans, the CN and vestibular nerve were unclear. Three scans with a common cavity showed only two nerve bundles. Conclusion The findings of this study show that the CN can be visualized in most inner‐ear anatomical types. Even in severely malformed inner ears, the common nerve bundle that represents the cochlear and vestibular nerves can be visualized. The MRI is highly recommended for CN assessment before CI surgery. Level of Evidence Level IV.

Abstract Objective To report a reliable method in obtaining optimal cochlear basal turn and cross‐section (c/s) of internal auditory canal (IAC) supporting Cochlear implantation (CI) procedure. Materials and Methods Computer tomography (CT) and magnetic resonance image (MRI) scans of potential CI candidates from 2018 to 2022 from the tertiary center were considered for analysis. Slicer software was used in three‐dimensional (3D) segmentation of inner ear and for capturing the cochlear basal turn. Results A total of 1932 head scans were made available for the analysis and out of which 1866 scans had normal anatomy (NA) inner ear. Incomplete partition (IP) type‐I was identified in 19 ears, IP type‐II in 27 ears, IP type‐III in 6 ears, cochlear hypoplasia (CH) type‐I in 6 ears, CH type‐II in 1 ear, CH type‐III in 3 ears, and CH type‐IV is 3 ears, and enlarged vestibular aqueduct syndrome in 1 ear. 3D segmented inner ear helped in successfully obtaining the cochlear basal turn and the c/s of IAC in all anatomical types. Time taken to capture the cochlear basal turn with the help of 3D segmented inner ear was

Abstract Objective We hypothesize that visualizing inner‐ear systematically in both cochlear view (oblique coronal plane) and in mid‐modiolar section (axial plane) and following three sequential steps simplifies, identification of inner‐ear malformation types. Methods Pre‐operative computer‐tomography (CT) scans of temporal bones of 112 ears with various inner ear malformation (IEM) types were taken for analysis. Images were analyzed using DICOM viewers, 3D slicer, and OTOPLAN®. The inner‐ear was captured in the oblique‐coronal plane for the measurement of length and width of cochlear basal turn which is also called as A‐, and B‐values respectively (Step 1). In the same plane, the angular‐turns of lateral‐wall (LW) of cochlear basal turn were measured (Step 2). As Step 3, the mid‐modiolar section of inner ear was captured in the axial plane by following the A‐value and perpendicular to cochlear view. From the mid‐modiolar section, the outer‐contour of inner ear was captured manually by following contrasting gray area between fluid filled and bony promontory and was compared to known resembling objects to identify IEM types (Step 3). Results Following reference values have emerged from our analysis: A‐, and B‐values (Step 1) on average are >8 mm and >5.5 mm respectively, in normal cochleae (NA), enlarged vestibular aqueduct syndrome (EVAS), incomplete partition (IP) type‐I and ‐II, whereas it is

Objectives: This study aimed to qualitatively evaluate the variations in nerve bundles between patients with normal anatomy and those with inner‐ear anomalies. Methods: Magnetic resonance imaging (MRI) scans of the temporal bones of candidates for cochlear implants (CIs) enrolled at a tertiary center were retrospectively reviewed from the clinical database. The 3.0‐Tesla MRI scans were analyzed using a three‐dimensional slicer to visualize the nerve bundles in the internal auditory canal. Results: A total of 49 ears were analyzed. Twenty ears exhibited normal inner ear anatomy, whereas 29 ears had various inner‐ear malformations. The cochlear nerve (CN) was visible on all 20 scans with normal inner‐ear anatomy. In addition, the CN was visualized in 18 scans with inner ear malformations. Furthermore, the CN was identified in six of the eight scans with IP type I, whereas in two scans, the CN and vestibular nerve were unclear. Three scans with a common cavity showed only two nerve bundles. Conclusion: The findings of this study show that the CN can be visualized in most inner‐ear anatomical types. Even in severely malformed inner ears, the common nerve bundle that represents the cochlear and vestibular nerves can be visualized. The MRI is highly recommended for CN assessment before CI surgery. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]