Article Figures & Data
Figures
- FIG 1.
Coronal oblique (cochlear view with thick MPR = 5 mm) CBCT image showing the measurement of the angle of insertion between the deepest electrode and the reference line joining the insertion point (round window/cochleostomy center) (a) and the center of a circle formed by the 3 most apical electrodes (b). The insertion angle = 360°- (c). The cochlear lateral wall is also well-visualized in this thick MPR coronal view (white arrows).
- FIG 2.
CBCT group. A, Midmodiolar view (cochlea) shows the modiolus (white arrow), the perfectly visualized cochlear lateral wall (black arrow), and the scalar translocation from ST to SV at the pars ascendens (dashed arrow). B, Axial view (cochlea) shows good visualization of single electrode contacts, C, Sagittal oblique view shows good visualization of the facial nerve canal wall (arrow). D, In the MDCT group, the midmodiolar view (cochlea) shows the modiolus (white arrow), nonvisualized cochlear lateral wall (artifacts) (black arrow), and the difficult scalar localization of the electrode (mostly ST). E, Axial view (cochlea) shows difficult identification of single electrode contacts and the osseous spiral lamina. F, Sagittal oblique view shows difficult identification of the facial nerve canal wall (arrow). ST indicates scala tympani; SV, scala vestibuli.
Tables
Electrodes Intercontact Distancing (mm) CBCT Group (n = 32) MDCT Group (n = 19) Widely spaced contacts FLEX28a 2.1 3 0 FLEX-Synchrony-Mediuma 1.9 2 2 HiRes MIDSCALAb 0.975 3 1 CI422*c 0.85–0.95 1 0 Narrowly spaced contacts CI24RE-CAc Nonuniform 0.4–0.8 9 0 CI512-CAc Nonuniform 0.4–0.8 3 0 CI532-CAc 0.6 11 1 CI24RE-STc 0.75 0 15 - Table 2:
Qualitative image scoring results for fine anatomic structures and metallic artifacts
Scale Points CBCT Group (n = 32) MDCT Group (n = 19) P Value Cochlear inner wall Not visualized (0) 1 (3%) 0 (0%) >.99 Barely visualized (1) 3 (9%) 2 (10.5%) Well-visualized (2) 6 (19%) 3 (15.8%) Perfectly visualized (3) 22 (69%) 14 (73.7%) Cochlear lateral wall Not visualized (0) 0 (0%) 1 (5%) .001 Barely visualized (1) 0 (0%) 0 (0%) Well-visualized-(2) 2 (6%) 8 (42%) Perfectly visualized (3) 30 (94%) 10 (53%) Modiolus Not visualized (0) 0 (0%) 0 (0%) .37 Barely visualized (1) 2 (6%) 0 (0%) Well-visualized (2) 5 (16%) 1 (5%) Perfectly visualized (3) 25 (78%) 18 (95%) Osseous spiral, lamina Not visualized (0) 18 (56%) 19 (100%) .002 Barely visualized (1) 10 (31%) 0 (0%) Well -visualized (2) 4 (13%) 0 (0%) Perfectly visualized (3) 0 (0%) 0 (0%) Mastoid facial, canal wall Not visualized (0) 4 (13%) 4 (21%) .07 Barely visualized (1) 10 (31%) 6 (32%) Well-visualized (2) 9 (28%) 9 (47%) Perfectly visualized (3) 9 (28%) 0 (0%) Metallic artifacts Very strong artifact (0) 0 (0%) 0 (0%) <.001 Strong artifacts (1) 6 (18.8%) 14 (74%) Moderate artifacts (2) 22 (68.8%) 5 (26%) Weak artifacts (3) 4 (12.5%) 0 (0%) Scale Points CBCT Group (n = 32) MDCT Group (n = 19) P Value Electrode scalar position Not visualized (0) 0 (0%) 0 (0%) .046 Barely visualized (1) 4 (13%) 3 (16%) Well-visualized (2) 3 (9%) 7 (37%) Perfectly visualized (3) 25 (78%) 9 (47%) Single electrode contact visibility Not visualized (0) 1 (3%) 10 (52.6%) <.001 Barely visualized (1) 13 (41%) 6 (31.6%) Well-visualized (2) 11 (34%) 0 (0%) Perfectly visualized (3) 7 (22%) 3 (15.8%) Insertion angle of electrode Not measurable (0) 0 (0%) 0 (0%) >.99 Measurable (1) 32 (100%) 19 (100%) Mean, 437.7° [SD, 120.8°] Mean, 329.4° [SD, 80°]
