Article Figures & Data
Figures
- Fig 1.
Output interface of the O-arm workstation and the case with foldover of the electrode array. The O-arm automatically shows the axial, sagittal, and coronal views on its screen after scanning and provides free 3D rotation (A). A foldover of the CI 532 electrode array was observed on the original and consecutive sagittal views (B–D). After a Cochlear CI 522 was re-implanted, the electrode array was verified in the correct position (E–G).
- Fig 2.
Examples of radiologic images of HRCT and the O-arm for 2 types of cochlear implants. MED-EL Flex 28 (A, B, E, F) and Cochlear CI 512 (C, D, G, H) electrode arrays were observed with both HRCT (A–D) and the O-arm (E–H), and with sagittal (A, C, E, G) and axial (B, D, F, H) views.
Tables
Demographics Age (mean ± SEM) (range) (yr) 53 ± 7.1 (20–87) Sex (M/F) 24:27 Anatomy Normal 64 ears Major aplasia 1 ear Implanted side Left 18 patients Right 19 patients Bilateral 14 patients Note:—SEM indicates standard error of the mean.
Devices Proprietary Name O-arm HRCT Advanced Bionics (16 electrodes) Helix 1J 2 Mid-Scala 3 Cochlear (22 electrodes) Perimodiolar CI 24, CI 512 12 2 CI 532 1 Straight CI 422, CI 522 31 9 MED-EL (12 electrodes) Flex 28 13 3 Oticon (20 electrodes) Evo 2 Standard 1 - Table 3:
Insertion depth angle and length of insertion of the electrode array—results from 2 raters using O-arm dataa
Implant Rater Depth Angle (°) Length (mm) Advanced Bionics A 384 ± 28.8 19.5 ± 1.02 (n = 5) B 389 ± 27.7 19.5 ± 0.96 Cochlear (perimodiolar) A 357 ± 10.1 18.8 ± 0.71 (n = 12) B 360 ± 9.5 18.6 ± 0.79 Cochlear (straight) A 425 ± 12.9 22.1 ± 0.47 (n = 31) B 427 ± 13.4 22.3 ± 0.47 MED-EL (n = 13) A 500 ± 30.0 24.1 ± 0.90 B 502 ± 30.0 24.4 ± 0.93 Oticon (n = 3) A 370 ± 13.2 23.4 ± 0.30 B 366 ± 21.7 23.4 ± 0.28 ↵a Values are mean ± standard error of the mean.
- Table 4:
Extracochlear electrode number and scalar position—difference in the results of 2 raters using O-arm data
Electrode No. Counting Rater A vs B Scalar Position at 180° Rater A vs B Scalar Position at 360°a Rater A vs B Same ±1 ±2 Same Different Same Different Advanced Bionics (n = 5) 3 (60%) 2 (40%) 4 (80%) 1 (20%) 2/3 (67%) 1/3 (33%) Cochlear (perimodiolar) (n = 12) 9 (75%) 2 (17%) 1 (8%) 6 (50%) 6 (50%) 5/9 (55%) 4/9 (45%) Cochlear (straight) (n = 31) 25 (80%) 3 (10%) 3 (10%) 14 (45%) 17 (55%) 6/21 (29%) 15/21 (71%) MED-EL (n = 13) 11 (85%) 2 (15%) 8 (62%) 5 (38%) 6/11 (55%) 5/11 (45%) Oticon (n = 3) 2 (67%) 1 (33%) 2 (67%) 1 (33%) 1/2 (50%) 1/2 (50%) Total (n = 64) 50b (78%) 9 (14%) 5 (8%) 34c (53%) 30 (47%) 20/46c (43%) 26/46 (57%) ↵a Some electrode arrays did not pass 360° depth, so the number of measurable cases at 360° was less than at 180°. The number of cases is indicated.
↵b Cohen κ = 0.53 (P < .001). Among the different array types, the raters' concordance showed no significant difference.
↵c Cohen κ < 0.2 (not significant).
- Table 5:
Extracochlear electrode number and scalar position—final results after coassessment using O-arm data
No. of Extracochlear Electrodes Scalar Position at 180° Scalar Position at 360°a 0 1 2 3 4 ST Int SV ST Int SV Advanced Bionics (n = 5) 2 (40%) 1 (20%) 2 (40%) 3 (60%) 1 (20%) 1 (20%) 2/3 (67%) 1/3 (33%) Cochlear (perimodiolar) (n = 12) 6 (50%) 3 (25%) 2 (17%) 1 (8%) 6 (50%) 5 (42%) 1 (8%) 3/9 (33%) 5/9 (56%) 1/9 (11%) Cochlear (straight) (n = 31) 26 (84%) 1 (3%) 1 (3%) 2 (6%) 1 (3%) 16 (52%) 12 (38%) 3 (10%) 5/21 (24%) 13/21 (62%) 3/21 (14%) MED-EL (n = 13) 10 (77%) 1 (8%) 2 (15%) 9 (69%) 4 (31%) 7/11 (64%) 4/11 (36%) Oticon (n = 3) 1 (33%) 1 (33%) 1 (33%) 1 (33%) 2 (67%) 1/2 (50%) 1/2 (50%) Total (n = 64) 45 (70%) 7 (11%) 8 (13%) 2 (3%) 2 (3%) 35 (55%) 24 (38%) 5 (7%) 18/46 (39%) 23/46 (50%) 5/46 (11%) Note:—ST indicates scala tympani; Int, intermediate position; SV: scala vestibuli.
↵a Some electrode arrays did not pass 360° depth, so the number of measurable cases at 360° was less than at 180°. The number of cases is indicated.
- Table 6:
Concordances of raters' coassessment between HRCT and O-arm—extracochlear electrode number and scalar position
No. of Extracochlear Electrodes HRCT vs O-Arm Scalar Position at 180° HRCT vs O-Arm Scalar Position at 360°a HRCT vs O-Arm Same ±1 Same Different Same Different Cochlear (n = 11) 10 (91%) 1 (9%) 8 (73%) 3 (27%) 6/9 (67%) 3/9 (33%) MED-EL (n = 3) 3 (100%) 3 (100%) 3/3 (100%) Total (n = 14) 13 (93%) 1 (7%) 11 (79%) 3 (21%) 9/12 (75%) 3/12 (25%) ↵a Some electrode arrays did not pass 360° depth, so the number of measurable cases at 360° was less than at 180°. The number of cases is indicated.
