Standardization of CT Depiction of Cochlear Implant Insertion Depth

Colby, Candice C.; Todd, N. Wendell; Harnsberger, H R; Hudgins, Patricia A.

doi:10.3174/ajnr.a4105

Cited by 20 publications

(7 citation statements)

References 13 publications

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“…All groups were instructed to estimate CI insertion depth in degrees based on post-op skull X-RAYs. We used the round window as the zero degree standard [16]. …”

Section: Methodsmentioning

confidence: 99%

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Effectiveness of skull X-RAY to determine cochlear implant insertion depth

Fernandes

Wang

Yeung

et al. 2018

Journal of Otolaryngology - Head & Neck Surgery

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BackgroundCochlear implant (CI) insertion depth can affect residual hearing preservation, tonotopic range coverage, and Mapping. Therefore, determining insertion depth has the potential to maximize CI performance. A post-op skull X-RAY is commonly used to assess insertion depth, however its effectiveness has not been well established. Our primary objective was to assess the accuracy of post-op skull X-RAYs to determine insertion depth, compared to CT as the gold standard. Secondary objectives were to compare experience level of raters and different skull X-RAY views.MethodsThirteen patients with Advanced Bionic HiRes 90 K implants, and post-operative temporal bone CT scans were selected from the CI database at Sunnybrook Health Sciences Centre. Medical students, otology fellows, and CI surgeons evaluated insertion depths on post-op skull X-RAYs, while neuroradiologists evaluated CT scans. Descriptive statistics, regression analysis, and paired t-tests were used to compare the two types of imaging.ResultsX-RAYs and CTs provided an equivalent mean insertion depth of 337 degrees (p = 0.93), a mean difference of − 0.9 degrees and a standard deviation of paired differences of 43 degrees. Although means were similar across rater groups, CI surgeons (45 degrees) had the lowest standard deviation of paired differences. Comparing X-RAY views, Caldwell (29 degrees) had less variation than Towne (59 degrees) for standard deviation of paired differences.ConclusionsSkull X-RAYs provide accurate and reliable measurements for CI insertion depth. The Caldwell view alone may be sufficient for evaluations of insertion depth, and experience has a minor impact on the variability of estimates.Electronic supplementary materialThe online version of this article (10.1186/s40463-018-0304-9) contains supplementary material, which is available to authorized users.

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“…All groups were instructed to estimate CI insertion depth in degrees based on post-op skull X-RAYs. We used the round window as the zero degree standard [16]. …”

Section: Methodsmentioning

confidence: 99%

“…CT is a highly accurate technique physicians currently utilize and can be reconstructed to yield 3D high-resolution data to determine electrode position [12, 14–16]. More commonly, immediate post-operative skull X-RAYs are performed following CI surgery at implant centres.…”

Section: Introductionmentioning

confidence: 99%

Effectiveness of skull X-RAY to determine cochlear implant insertion depth

Fernandes

Wang

Yeung

et al. 2018

Journal of Otolaryngology - Head & Neck Surgery

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“…dungen der Kochlea werden mithilfe von 2 senkrechten Linien in 10 Quadranten unterteilt, die für die standardisierte CT-Klassifikation der Kochleainsertionstiefe verwendet werden können [22,23]. Das ovale Fenster beherbergt die Steigbügelfußplatte und kommuniziert mit dem Vestibulum des Innenohrs.…”

Section: Pr a Xistippunclassified

Kochleaimplantat: systematischer Ansatz zur präoperativen radiologischen Evaluation

Hiremath,

Biswas,

Mndebele

et al. 2024

Neuroradiologie Scan

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“…For a more accurate and standardized depiction of the electrode, the quadrant nomenclature of the cochlea introduced by Colby et al was used [17].…”

Section: Scan Protocolmentioning

confidence: 99%

Comparison of 96-kV and 120-kV Cone-Beam CT for the Assessment of Cochlear Implants

Burck

Yel

Martin

et al. 2023

Preprint

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Background: To compare the diagnostic value of 120-kV with conventional 96-kV Cone-Beam CT (CBCT) of the temporal bone after cochlear implant (CI) surgery.Methods: This retrospective study included CBCT scans after CI surgery between 06/17 and 01/18. CBCT allowed examinations with 96-kV or 120-kV; other parameters were the same. Two radiologists independently evaluated following criteria on 5-point Likert scales: osseous spiral lamina, inner and outer cochlear wall, semi-circular canals, mastoid trabecular structure, overall image quality, metal and motion artefacts, depiction of intracochlear electrode position and visualisation of single electrode contacts. Effective radiation dose was assessed.Results: Seventy-five patients (females, n = 39 [52.0%], mean age, 55.8 ± 16.5 years) were scanned with 96-kV (n = 32, 42.7%) and 120-kV (n = 43, 57.3%) protocols including CI models from three vendors (vendor A n = 7; vendor B n = 43; vendor C n = 25). Overall image quality, depiction of anatomical structures, and electrode position were rated significantly better in 120-kV images compared to 96-kV (all p < = 0.018). Anatomical structures and electrode position were rated significantly better in 120-kV CBCT for CI models from vendor A and C, while 120-kV did not provide improved image quality in CI models from vendor B. Radiation doses were significantly higher for 120-kV scans compared to 96-kV (0.15 vs. 0.08 mSv, p < 0.001).Conclusions: 120-kV and 96-kV CBCT provide good diagnostic images for the postoperative CI evaluation. While 120-kV showed improved depiction of temporal bone and CI electrode position compared to 96-kV in most CI models, the 120-kV protocol should be chosen wisely due to a substantially higher radiation exposure.

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Standardization of CT Depiction of Cochlear Implant Insertion Depth

Cited by 20 publications

References 13 publications

Effectiveness of skull X-RAY to determine cochlear implant insertion depth

Effectiveness of skull X-RAY to determine cochlear implant insertion depth

Kochleaimplantat: systematischer Ansatz zur präoperativen radiologischen Evaluation

Comparison of 96-kV and 120-kV Cone-Beam CT for the Assessment of Cochlear Implants

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