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1.
Laryngorhinootologie ; 101(5): 428-441, 2022 05.
Artigo em Alemão | MEDLINE | ID: mdl-35500581

RESUMO

Personalized care in the context of cochlear implantation is becoming increasingly important. Choosing the right electrode could improve speech understanding. The measurement of the cochlear length plays an important role: preoperatively, in order to select a suitable electrode length; postoperatively, on the one hand to check the correct electrode position, on the other hand to enable anatomically based fitting of the electrode contacts. Of the various possible localizations of the CDL measurements within the cochlear turns, the one on the organ of Corti (CDLOC) is the most frequently used and clinically most important. In the CDL measurement, a direct and indirect evaluation can be distinguished. There is also the possibility of reconstructing and measuring the CDL in 3D and calculating it mathematically, e.g. using spiral equations. In this context, measurements based on radiological imaging are gaining increasing importance. Therefore, if there is the possibility of performing higher-resolution imaging, this should be strived preoperatively in order to enable the most precise possible procedure and thus a good outcome. Otological planning software can help to create an interface between new findings regarding CDL measurement and higher-resolution imaging for an individualized cochlear implantation.


Assuntos
Implante Coclear , Implantes Cocleares , Cóclea/diagnóstico por imagem , Cóclea/cirurgia , Ducto Coclear/cirurgia , Implante Coclear/métodos , Humanos , Tomografia Computadorizada por Raios X/métodos
2.
Eur Arch Otorhinolaryngol ; 279(5): 2309-2319, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34101009

RESUMO

PURPOSE: For further improvements in cochlear implantation, the measurement of the cochlear duct length (CDL) and the determination of the electrode contact position (ECP) are increasingly in the focus of clinical research. Usually, these items were investigated by multislice computed tomography (MSCT). The determination of ECP was only possible by research programs so far. Flat-panel volume computed tomography (fpVCT) and its secondary reconstructions (fpVCTSECO) allow for high spatial resolution for the visualization of the temporal bone structures. Using a newly developed surgical planning software that enables the evaluation of CDL and the determination of postoperative ECP, this study aimed to investigate the combination of fpVCT and otological planning software to improve the implementation of an anatomically based cochlear implantation. METHODS: Cochlear measurements were performed utilizing surgical planning software in imaging data (MSCT, fpVCT and fpVCTSECO) of patients with and without implanted electrodes. RESULTS: Measurement of the CDL by the use of an otological planning software was highly reliable using fpVCTSECO with a lower variance between the respective measurements compared to MSCT. The determination of the inter-electrode-distance (IED) between the ECP was improved in fpVCTSECO compared to MSCT. CONCLUSION: The combination of fpVCTSECO and otological planning software permits a simplified and more reliable analysis of the cochlea in the pre- and postoperative setting. The combination of both systems will enable further progress in the development of an anatomically based cochlear implantation.


Assuntos
Implante Coclear , Implantes Cocleares , Cóclea/diagnóstico por imagem , Cóclea/cirurgia , Ducto Coclear , Implante Coclear/métodos , Tomografia Computadorizada de Feixe Cônico , Humanos , Software
3.
Eur Arch Otorhinolaryngol ; 279(4): 1851-1861, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34050805

RESUMO

PURPOSE: In cochlear implantation, thorough preoperative planning together with measurement of the cochlear duct length (CDL) assists in choosing the correct electrode length. For measuring the CDL, different techniques have been introduced in the past century along with the then available technology. A tablet-based software offers an easy and intuitive way to visualize and analyze the anatomy of the temporal bone, its proportions and measure the CDL. Therefore, we investigated the calculation technique of the CDL via a tablet-based software on our own cohort retrospectively. METHODS: One hundred and eight preoperative computed tomography scans of the temporal bone (slice thickness < 0.7 mm) of already implanted FLEX28™ and FLEXSOFT™ patients were found eligible for analysis with the OTOPLAN software. Measurements were performed by two trained investigators independently. CDL, angular insertion depth (AID), and cochlear coverage were calculated and compared between groups of electrode types, sex, sides, and age. RESULTS: Mean CDL was 36.2 ± 1.8 mm with significant differences between sex (female: 35.8 ± 0.3 mm; male: 36.5 ± 0.2 mm; p = 0.037), but none concerning side or age. Differences in mean AID (FLEX28: 525.4 ± 46.4°; FLEXSOFT: 615.4 ± 47.6°), and cochlear coverage (FLEX28: 63.9 ± 5.6%; FLEXSOFT: 75.8 ± 4.3%) were significant (p < 0.001). CONCLUSION: A broad range of CDL was observed with significant larger values in male, but no significant differences concerning side or age. Almost every cochlea was measured longer than 31.0 mm. Preoperative assessment aids in prevention of complications (incomplete insertion, kinking, tipfoldover), attempt of atraumatic insertion, and addressing individual necessities (hearing preservation, cochlear malformation). The preferred AID of 720° (two turns of the cochlea) was never reached, opening the discussion for the requirement of longer CI-electrodes versus a debatable audiological benefit for the patient in his/her everyday life.


Assuntos
Implante Coclear , Implantes Cocleares , Cóclea/diagnóstico por imagem , Cóclea/cirurgia , Ducto Coclear , Implante Coclear/métodos , Feminino , Humanos , Masculino , Estudos Retrospectivos , Software , Osso Temporal/diagnóstico por imagem , Osso Temporal/cirurgia
4.
Cochlear Implants Int ; 23(1): 32-42, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34519256

RESUMO

OBJECTIVE: There is still a lack in precise postoperative evaluation of the cochlea because of strong artifacts. This study aimed to improve accuracy of postoperative two-turn (2TL) and cochlear duct length (CDL) measurements by applying flat-panel volume computed tomography (fpVCT), secondary reconstruction (fpVCTSECO) and three-dimensional curved multiplanar reconstruction. METHODS: First, 10 temporal bone specimens with or without electrode were measured in multi-slice computed tomography (MSCT), fpVCT and fpVCTSECO and compared to high-resolution micro-CT scans. Later, pre- and postoperative scans of 10 patients were analyzed in a clinical setting. RESULTS: Concerning 2TL, no statistically significant difference was observed between implanted fpVCTSECO and nonimplanted micro-CT in 10 temporal bone specimens. In contrast, there was a significant discrepancy for CDL (difference: -0.7 mm, P = 0.004). Nevertheless, there were no clinically unacceptable errors (±1.5 mm). These results could be confirmed in a clinical setting. Using fpVCTSECO, CDL was slightly underestimated postoperatively (difference: -0.5 mm, P = 0.002) but without any clinically unacceptable errors. CONCLUSION: fpVCTSECO can be successfully applied for a precise measurement of the cochlear lengths pre- and postoperatively. However, users must be aware of a slight systematic underestimation of CDL postoperatively. These results may help to refine electrode selection and frequency mapping.


Assuntos
Implante Coclear , Implantes Cocleares , Cóclea/diagnóstico por imagem , Cóclea/cirurgia , Ducto Coclear/cirurgia , Implante Coclear/métodos , Tomografia Computadorizada de Feixe Cônico , Humanos , Osso Temporal/diagnóstico por imagem , Osso Temporal/cirurgia
5.
Eur Radiol ; 32(2): 1014-1023, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34463797

RESUMO

OBJECTIVES: Knowledge about cochlear duct length (CDL) may assist electrode choice in cochlear implantation (CI). However, no gold standard for clinical applicable estimation of CDL exists. The aim of this study is (1) to determine the most reliable radiological imaging method and imaging processing software for measuring CDL from clinical routine imaging and (2) to accurately predict the insertion depth of the CI electrode. METHODS: Twenty human temporal bones were examined using different sectional imaging techniques (high-resolution computed tomography [HRCT] and cone beam computed tomography [CBCT]). CDL was measured using three methods: length estimation using (1) a dedicated preclinical 3D reconstruction software, (2) the established A-value method, and (3) a clinically approved otosurgical planning software. Temporal bones were implanted with a 31.5-mm CI electrode and measurements were compared to a reference based on the CI electrode insertion angle measured by radiographs in Stenvers projection (CDLreference). RESULTS: A mean cochlear coverage of 74% (SD 7.4%) was found. The CDLreference showed significant differences to each other method (p < 0.001). The strongest correlation to the CDLreference was found for the otosurgical planning software-based method obtained from HRCT (CDLSW-HRCT; r = 0.87, p < 0.001) and from CBCT (CDLSW-CBCT; r = 0.76, p < 0.001). Overall, CDL was underestimated by each applied method. The inter-rater reliability was fair for the CDL estimation based on 3D reconstruction from CBCT (CDL3D-CBCT; intra-class correlation coefficient [ICC] = 0.43), good for CDL estimation based on 3D reconstruction from HRCT (CDL3D-HRCT; ICC = 0.71), poor for CDL estimation based on the A-value method from HRCT (CDLA-HRCT; ICC = 0.29), and excellent for CDL estimation based on the A-value method from CBCT (CDLA-CBCT; ICC = 0.87) as well as for the CDLSW-HRCT (ICC = 0.94), CDLSW-CBCT (ICC = 0.94) and CDLreference (ICC = 0.87). CONCLUSIONS: All approaches would have led to an electrode choice of rather too short electrodes. Concerning treatment decisions based on CDL measurements, the otosurgical planning software-based method has to be recommended. The best inter-rater reliability was found for CDLA-CBCT, for CDLSW-HRCT, for CDLSW-CBCT, and for CDLreference. KEY POINTS: • Clinically applicable calculations using high-resolution CT and cone beam CT underestimate the cochlear size. • Ten percent of cochlear duct length need to be added to current calculations in order to predict the postoperative CI electrode position. • The clinically approved otosurgical planning software-based method software is the most suitable to estimate the cochlear duct length and shows an excellent inter-rater reliability.


Assuntos
Implante Coclear , Implantes Cocleares , Cóclea/diagnóstico por imagem , Ducto Coclear/cirurgia , Tomografia Computadorizada de Feixe Cônico , Eletrodos Implantados , Humanos , Reprodutibilidade dos Testes , Osso Temporal/diagnóstico por imagem , Tomografia Computadorizada por Raios X
6.
Cochlear Implants Int ; 23(2): 59-69, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34590531

RESUMO

OBJECTIVE: To assess whether the pre-operative electrode to cochlear duct length ratio (ECDLR), is associated with post-operative speech recognition outcomes. STUDY DESIGN: A retrospective chart review study. SETTING: Tertiary referral center. PATIENTS: The study included sixty-one adult CI recipients with a pre-operative computed tomography scan and a speech recognition test 12 months after implantation. INTERVENTIONS: The average of two raters' cochlear duct length (CDL) measurements and the length of the recipient's cochlear implant electrode array formed the basis for the electrode-to-cochlear duct length ratio (ECLDR). Speech recognition tests were compared as a function of ECDLR and electrode array length itself. MAIN OUTCOME MEASURES: The relationship between ECDLR and percent correct on speech recognition tests. RESULTS: A second order polynomial regression relating ECDLR to percent correct on the CNC words speech recognition test was statistically significant, as was a fourth order polynomial regression for the AzBio Quiet test. In contrast, there was no statistically significant relationship between speech recognition scores and electrode array length. CONCLUSIONS: ECDLR values can be statistically associated to speech-recognition outcomes. However, these ECDLR values cannot be predicted by the electrode length alone, and must include a measure of CDL.


Assuntos
Implante Coclear , Implantes Cocleares , Percepção da Fala , Adulto , Ducto Coclear , Implante Coclear/métodos , Humanos , Estudos Retrospectivos , Fala , Resultado do Tratamento
7.
Laryngoscope ; 132(2): 449-458, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34536238

RESUMO

OBJECTIVES/HYPOTHESIS: To present and validate a novel fully automated method to measure cochlear dimensions, including cochlear duct length (CDL). STUDY DESIGN: Cross-sectional study. METHODS: The computational method combined 1) a deep learning (DL) algorithm to segment the cochlea and otic capsule and 2) geometric analysis to measure anti-modiolar distances from the round window to the apex. The algorithm was trained using 165 manually segmented clinical computed tomography (CT). A Testing group of 159 CTs were then measured for cochlear diameter and width (A- and B-values) and CDL using the automated system and compared against manual measurements. The results were also compared with existing approaches and historical data. In addition, pre- and post-implantation scans from 27 cochlear implant recipients were studied to compare predicted versus actual array insertion depth. RESULTS: Measurements were successfully obtained in 98.1% of scans. The mean CDL to 900° was 35.52 mm (SD, 2.06; range, [30.91-40.50]), the mean A-value was 8.88 mm (0.47; [7.67-10.49]), and mean B-value was 6.38 mm (0.42; [5.16-7.38]). The R2 fit of the automated to manual measurements was 0.87 for A-value, 0.70 for B-value, and 0.71 for CDL. For anti-modiolar arrays, the distance between the imaged and predicted array tip location was 0.57 mm (1.25; [0.13-5.28]). CONCLUSION: Our method provides a fully automated means of cochlear analysis from clinical CTs. The distribution of CDL, dimensions, and cochlear quadrant lengths is similar to those from historical data. This approach requires no radiographic experience and is free from user-related variation. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:449-458, 2022.


Assuntos
Ducto Coclear/anatomia & histologia , Ducto Coclear/diagnóstico por imagem , Osso Temporal/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Automação , Estudos Transversais , Humanos , Pessoa de Meia-Idade , Tamanho do Órgão
8.
In Vivo ; 35(6): 3339-3344, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34697167

RESUMO

BACKGROUND: The aim of this study was to compare three different methods for measurement of cochlear duct length (CDL) in the clinical setting for two different imaging modalities, namely computed tomography (CT) and cone-beam computed tomography (CBCT). PATIENTS AND METHODS: One hundred temporal bone data sets (CT: n=50; CBCT: n=50) of non-malformed cochleae were retrospectively analyzed using three different CDL estimation techniques: 3D curved multiplanar reconstruction (cMPR), 2D cMPR and the A-value formula. RESULTS: The data sets belonged to 60 patients (34 males, 26 females; mean age=50.28±18.58 years). For both imaging modalities, application of the 3D cMPR estimation technique led to significantly greater mean CDL values than the two-dimensional methods (p<0.0083). The CDL measurements viewed in CT imaging software were significantly shorter than the corresponding CBCT measurements (p<0.05). Using a linear mixed model, differences in CDL by sex (p=0.796), age (p=0.377) and side of ear (p=0.690) were not significant. CONCLUSION: The 3D cMPR technique was found to provide the most accurate in vivo CDL measurement in non-malformed cochlea in both CT and CBCT imaging compared to 2D methods. The study results also suggest that the higher spatial resolution in CBCT imaging results in more precise CDL determination than in CT.


Assuntos
Implante Coclear , Adulto , Idoso , Ducto Coclear/cirurgia , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
9.
J Assoc Res Otolaryngol ; 22(6): 681-691, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34622375

RESUMO

Incomplete partition type II (IP-II) is frequently identified in ears with SLC26A4 mutations. Cochleae with IP-II are generally observed to have 1½ turns; the basal turns are normally formed, and the apical turn is dilated or cystic. The objective of this study was to characterize the pathomorphogenesis of the IP-II cochlear anomaly in Slc26a4-null mice. Otic capsules were dissected from Slc26a4Δ/+ and Slc26a4Δ/Δ mice at 1 and 8 days of age and at 1 and 3 months of age. X-ray micro-computed tomography was used to image samples. We used a multiplanar view and three-dimensional reconstructed models to calculate the cochlear duct length, cochlear turn rotation angle, and modiolus tilt angle. The number of inner hair cells was counted, and the length of the cochlear duct was measured in a whole-mount preparation of the membranous labyrinth. X-ray micro-computed tomography mid-modiolar planar views demonstrated cystic apical turns in Slc26a4Δ/Δ mice resulting from the loss or deossification of the interscalar septum, which morphologically resembles IP-II in humans. Planes vertical to the modiolus showed a similar mean rotation angle between Slc26a4Δ/+ and Slc26a4Δ/Δ mice. In contrast, the mean cochlear duct length and mean number of inner hair cells in Slc26a4Δ/Δ mice were significantly smaller than in Slc26a4Δ/+ mice. In addition, there were significant differences in the mean tilt angle and mean width of the modiolus. Our analysis of Slc26a4-null mice suggests that IP-II in humans reflects loss or deossification of the interscalar septum but not a decreased number of cochlear turns.


Assuntos
Cóclea/anormalidades , Cóclea/diagnóstico por imagem , Orelha Interna/diagnóstico por imagem , Células Ciliadas Vestibulares , Transportadores de Sulfato/genética , Animais , Cóclea/anatomia & histologia , Ducto Coclear , Orelha Interna/anormalidades , Células Ciliadas Auditivas Internas , Camundongos , Camundongos Knockout , Tomografia Computadorizada por Raios X , Microtomografia por Raio-X
10.
AJNR Am J Neuroradiol ; 42(11): 2016-2022, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34593380

RESUMO

BACKGROUND AND PURPOSE: Prior studies have evaluated cochlear length using CT to select the most suitable cochlear implants and obtain patient-specific anatomy. This study aimed to test the accuracy and reliability of cochlear lateral wall length measurements using 3D MR imaging. MATERIALS AND METHODS: Two observers measured the cochlear lateral wall length of 35 patients (21 men) with postlingual hearing loss using CT and MR imaging. The intraclass correlation coefficient (with 95% confidence intervals) was used to evaluate intraobserver and interobserver reliability for the 3D cochlear measurements. RESULTS: The mean age of the participants was 39.85 (SD, 16.60) years. Observer 1 measured the mean lateral wall length as 41.52 (SD, 2.25) mm on CT and 41.44 (SD, 2.18) mm on MR imaging, with a mean difference of 0.08 mm (95% CI, -0.11 to 0.27 mm), while observer 2 measured the mean lateral wall length as 41.74 (SD, 2.69) mm on CT and 42.34 (SD, 2.53) mm on MR imaging, with a mean difference of -0.59 mm (95% CI, -1.00 to -0.20 mm). An intraclass correlation coefficient value of 0.90 (95% CI, 0.84-0.94) for CT and 0.69 (95% CI, 0.46-0.82) for MR imaging was obtained for the interobserver reliability for the full-turn cochlear lateral wall length. CONCLUSIONS: CT-based 3D cochlear measurements show excellent intraobserver and interobserver reliability, while MR imaging-based lateral wall length measurements have good-to-excellent intraobserver reliability and moderate interobserver reliability. These results corroborate the use of CT for 3D cochlear measurements as a reference method and demonstrate MR imaging to be an alternative acquisition technique with comparably reliable results.


Assuntos
Ducto Coclear , Tomografia Computadorizada por Raios X , Adulto , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Reprodutibilidade dos Testes
11.
Otol Neurotol ; 42(6): e658-e665, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34111048

RESUMO

HYPOTHESIS: Measuring the length of the basilar membrane (BM) in the cochlear hook region will result in improved accuracy of cochlear duct length (CDL) measurements. BACKGROUND: Cochlear implant pitch mapping is generally performed in a patient independent approach, which has been shown to result in place-pitch mismatches. In order to customize cochlear implant pitch maps, accurate CDL measurements must be obtained. CDL measurements generally begin at the center of the round window (RW) and ignore the basal-most portion of the BM in the hook region. Measuring the size and morphology of the BM in the hook region can improve CDL measurements and our understanding of cochlear tonotopy. METHODS: Ten cadaveric human cochleae underwent synchrotron radiation phase-contrast imaging. The length of the BM through the hook region and CDL were measured. Two different CDL measurements were obtained for each sample, with starting points at the center of the RW (CDLRW) and the basal-most tip of the BM (CDLHR). Regression analysis was performed to relate CDLRW to CDLHR. A three-dimensional polynomial model was determined to describe the average BM hook region morphology. RESULTS: The mean CDLRW value was 33.03 ±â€Š1.62 mm, and the mean CDLHR value was 34.68 ±â€Š1.72 mm. The following relationship was determined between CDLRW and CDLHR: CDLHR  = 1.06(CDLRW)-0.26 (R2  = 0.99). CONCLUSION: The length and morphology of the hook region was determined. Current measurements underestimate CDL in the hook region and can be corrected using the results herein.


Assuntos
Implante Coclear , Implantes Cocleares , Cóclea/diagnóstico por imagem , Ducto Coclear/cirurgia , Humanos , Tomografia Computadorizada por Raios X
12.
Science ; 372(6542): 610-613, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33958472

RESUMO

Owls and nightbirds are nocturnal hunters of active prey that combine visual and hearing adaptations to overcome limits on sensory performance in low light. Such sensory innovations are unknown in nonavialan theropod dinosaurs and are poorly characterized on the line that leads to birds. We investigate morphofunctional proxies of vision and hearing in living and extinct theropods and demonstrate deep evolutionary divergences of sensory modalities. Nocturnal predation evolved early in the nonavialan lineage Alvarezsauroidea, signaled by extreme low-light vision and increases in hearing sensitivity. The Late Cretaceous alvarezsauroid Shuvuuia deserti had even further specialized hearing acuity, rivaling that of today's barn owl. This combination of sensory adaptations evolved independently in dinosaurs long before the modern bird radiation and provides a notable example of convergence between dinosaurs and mammals.


Assuntos
Adaptação Fisiológica , Evolução Biológica , Ducto Coclear/anatomia & histologia , Dinossauros/anatomia & histologia , Dinossauros/fisiologia , Audição , Visão Noturna , Animais , Dinossauros/líquido cefalorraquidiano , Filogenia , Estrigiformes/anatomia & histologia , Estrigiformes/fisiologia
13.
Sci Rep ; 11(1): 7339, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33795738

RESUMO

The A-value used in cochlear duct length (CDL) estimation does not take malformed cochleae into consideration. The objective was to determine the A-value reported in the literature, to assess the accuracy of the A-value measurement and to evaluate a novel cochlear measurement in distinguishing malformed cochlea. High resolution Computer Tomography images in the oblique coronal plane/cochlear view of 74 human temporal bones were analyzed. The A-value and novel C-value measurement were evaluated as predictors of inner ear malformation type. The proximity of the facial nerve to the basal turn was evaluated subjectively. 26 publications report on the A-value; but they do not distinguish normal vs. malformed cochleae. The A-values of the normal cochleae compared to the cochleae with cochlear hypoplasia, incomplete partition (IP) type I, -type II, and -type III were significantly different. The A-value does not predict the C-value. The C-values of the normal cochleae compared to the cochleae with IP type I and IP type III were significantly different. The proximity of the facial nerve to the basal turn did not relate to the type of malformation. The A-value is different in normal vs. malformed cochleae. The novel C-value could be used to predict malformed anatomy, although it does not distinguish all malformation types.


Assuntos
Cóclea/anormalidades , Cóclea/anatomia & histologia , Osso Temporal/anormalidades , Osso Temporal/anatomia & histologia , Tomografia Computadorizada por Raios X/métodos , Cóclea/diagnóstico por imagem , Ducto Coclear , Implante Coclear/métodos , Nervo Facial/anatomia & histologia , Nervo Facial/diagnóstico por imagem , Perda Auditiva Neurossensorial/diagnóstico por imagem , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Análise de Regressão , Reprodutibilidade dos Testes , Osso Temporal/diagnóstico por imagem
14.
Otol Neurotol ; 42(8): 1149-1155, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33859134

RESUMO

OBJECTIVES: To characterize the relationship between cochlear duct length (CDL) and initial hearing preservation among cochlear implant recipients of a fully inserted 31.5 mm flexible lateral wall electrode array. STUDY DESIGN: Retrospective review. SETTING: Tertiary academic referral center. PATIENTS: Adult cochlear implant recipients who presented preoperatively with unaided hearing detection thresholds of ≤ 65 dB HL at 125 Hz and underwent cochlear implantation with a 31.5 mm flexible lateral wall array. INTERVENTION: Cochlear implantation with a hearing preservation surgical approach. MAIN OUTCOME MEASURES: Computed tomography was reviewed to determine CDL. Hearing preservation was characterized by the shift in low-frequency pure-tone average (LFPTA; 125, 250, and 500 Hz), and shift in individual unaided hearing detection thresholds at 125, 250, and 500 Hz. RESULTS: Nineteen patients met the criteria for inclusion. The mean CDL was 34.2 mm (range: 30.8-36.5 mm). Recipients experienced a mean LFPTA shift of 27.6 dB HL (range: 10-50 dB HL). Significant, negative correlations were observed between CDL and smaller threshold shifts at individual frequencies and LFPTA (p ≤ 0.048). CONCLUSION: A longer CDL is associated with greater likelihood of preserving low-frequency hearing with long arrays. Low-frequency hearing preservation is feasible with fully inserted long flexible arrays within the initial months after cochlear implantation. Preoperative measurement of CDL may facilitate a more individualized approach in array selection to permit optimal cochlear coverage while enhancing hearing preservation outcomes.


Assuntos
Implante Coclear , Implantes Cocleares , Adulto , Audiometria de Tons Puros , Limiar Auditivo , Ducto Coclear , Audição , Humanos , Estudos Retrospectivos , Resultado do Tratamento
15.
Elife ; 102021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33667159

RESUMO

A notable example of spiral architecture in organs is the mammalian cochlear duct, where the morphology is critical for hearing function. Genetic studies have revealed necessary signaling molecules, but it remains unclear how cellular dynamics generate elongating, bending, and coiling of the cochlear duct. Here, we show that extracellular signal-regulated kinase (ERK) activation waves control collective cell migration during the murine cochlear duct development using deep tissue live-cell imaging, Förster resonance energy transfer (FRET)-based quantitation, and mathematical modeling. Long-term FRET imaging reveals that helical ERK activation propagates from the apex duct tip concomitant with the reverse multicellular flow on the lateral side of the developing cochlear duct, resulting in advection-based duct elongation. Moreover, model simulations, together with experiments, explain that the oscillatory wave trains of ERK activity and the cell flow are generated by mechanochemical feedback. Our findings propose a regulatory mechanism to coordinate the multicellular behaviors underlying the duct elongation during development.


Assuntos
Movimento Celular , Ducto Coclear/embriologia , Sistema de Sinalização das MAP Quinases , Animais , Embrião de Mamíferos , Transferência Ressonante de Energia de Fluorescência , Camundongos Endogâmicos ICR , Camundongos Transgênicos , Modelos Teóricos , Morfogênese
16.
Otol Neurotol ; 42(7): e875-e880, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33710146

RESUMO

OBJECTIVE: To describe a new method to measure the cochlear parameters using Otoplan software, and to compare it with the traditional method using curved multiplanar reconstruction (cMPR). STUDY DESIGN: Retrospective analysis using internal consistency reliability and paired sample t test. SETTING: Tertiary referral center. PATIENTS: Thirty-four patients including 68 ears from a clinical trial were retrospectively reviewed. MAIN OUTCOME MEASURES: The length, width, height (distances A, B, H), and cochlear duct length of each cochlea were measured independently using two modalities: Otoplan and cMPR. Internal consistency reliability of the two modalities was analyzed. The time spent on each measurement was also recorded. RESULTS: Otoplan software was compatible with all radiological data in this series. Distances A, B, and H showed no significant differences between Otoplan (9.33 ±â€Š0.365, 6.61 ±â€Š0.359, and 2.91 ±â€Š0.312 mm) and cMPR (9.32 ±â€Š0.314, 6.59 ±â€Š0.342, and 2.93 ±â€Š0.250 mm). The average cochlear duct length calculated by Otoplan was 34.37 ±â€Š1.481 mm, which was not significantly different from that calculated by cMPR (34.55 ±â€Š1.903mm, p = 0.215). The measurements with Otoplan had better internal consistency reliability compared with those by cMPR, and measurements with a higher peak kilovoltage (140 kVp) CT scan showed further higher internal consistency reliability. Time spent on each cochlea by Otoplan was 5.9 ±â€Š0.69 min, significantly shorter than that by cMPR (9.3 ±â€Š0.72 min). CONCLUSION: Otoplan provides more rapid and reliable measurement of the cochlea than cMPR. Furthermore, it can be easily used in the laptop computer.


Assuntos
Implante Coclear , Implantes Cocleares , Cóclea/diagnóstico por imagem , Cóclea/cirurgia , Ducto Coclear , Humanos , Reprodutibilidade dos Testes , Estudos Retrospectivos
17.
Lasers Med Sci ; 36(9): 1917-1925, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33604771

RESUMO

Photobiomodulation (PBM) is a therapeutic approach to certain diseases based on light energy. Currently, stem cells (SCs) are being considered as putative treatments for previously untreatable diseases. One medical condition that could be treated using SCs is sensorineural hearing loss. Theoretically, if properly delivered and differentiated, SCs could replace lost hair cells in the cochlea. However, this is not currently possible due to the structural complexity and limited survival of SCs within the cochlea. PBM facilitates SC differentiation into other target cells in multiple lineages. Using light with a wavelength > 800 nm, which can penetrate the inner ear through the tympanic membrane, we assessed morphological changes of mouse embryonic stem cells (mESCs) during "otic organoid" generation, and within the scala media (SM) of the cochlea, after light energy stimulation. We observed enhanced differentiation, which was confirmed by an increased number of otic vesicles and increased cell attachment inside the SM. These results suggest that > 800-nm light affected the morphology of mESCs within otic organoids and SM of the cochlea. Based on our results, light energy could be used to enhance otic sensory differentiation, despite the structural complexity of the inner ear and limited survival time of SCs within the cochleae. Additional studies to refine the light energy delivery technology and maximize the effect on otic differentiation are required.


Assuntos
Orelha Interna , Organoides , Animais , Diferenciação Celular , Cóclea , Ducto Coclear , Camundongos , Células-Tronco
18.
Ear Hear ; 42(3): 732-743, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33538429

RESUMO

OBJECTIVES: To determine the sources of variability for cochlear duct length (CDL) measurements for the purposes of fine-tuning cochlear implants (CI) and to propose a set of standardized landmarks for computed tomography (CT) pitch mapping. DESIGN: This was a retrospective cohort study involving 21 CI users at a tertiary referral center. The intervention involved flat-panel CT image acquisition and secondary reconstructions of CIs in vivo. The main outcome measures were CDL measurements, CI electrode localization measurements, and frequency calculations. RESULTS: Direct CT-based measurements of CI and intracochlear landmarks are methodologically valid, with a percentage of error of 1.0% ± 0.9%. Round window (RW) position markers (anterior edge, center, or posterior edge) and bony canal wall localization markers (medial edge, duct center, or lateral edge) significantly impact CDL calculations [F(2, 78) = 9.9, p < 0.001 and F(2, 78) = 1806, p < 0.001, respectively]. These pitch distortions could be as large as 11 semitones. When using predefined anatomical landmarks, there was still a difference between researchers [F(2, 78) = 12.5; p < 0.001], but the average variability of electrode location was reduced to differences of 1.6 semitones (from 11 semitones. CONCLUSIONS: A lack of standardization regarding RW and bony canal wall landmarks results in great CDL measurement variability and distorted pitch map calculations. We propose using the posterior edge of the RW and lateral bony wall as standardized anatomical parameters for CDL calculations in CI users to improve pitch map calculations. More accurate and precise pitch maps may improve CI-associated pitch outcomes.


Assuntos
Implante Coclear , Implantes Cocleares , Ducto Coclear/cirurgia , Humanos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
19.
Otol Neurotol ; 42(3): e294-e303, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33555750

RESUMO

HYPOTHESIS: Flat-panel volume computed tomography (fpVCT) and secondary reconstruction allow for more accurate measurements of two-turn length (2TL), cochlear duct length (CDL), and angular length (AL). BACKGROUND: Cochlear geometry is a controversially debated topic. In the meantime, there are many different studies partly reporting highly divergent values. Our aim is to discuss the differences and to propose a radiological possibility to improve cochlear measurements using 3D-curved multiplanar reconstruction and fpVCT. METHODS: Performing different image modalities and settings, we tried to find a clinically usable option that allows for a high degree of accuracy. Therefore, we tested them against reference values of high-definition micro-computed tomography. RESULTS: Comparison of 99 µm slice thickness secondary reconstruction of fpVCT and reference showed no significant differences for 2TL and CDL (p ≥ 0.05). Accordingly, ICC (intraclass correlation) values were excellent (ICC ≥ 0.75; lower limit of confidence interval [CI] ≥ 0.75; Cronbach's alpha [α] ≥ 0.9). Evaluating AL, there was a significant difference (difference: -17.27°; p = 0.002). The lower limit of the CI of the ICC was unacceptable (ICC = 0.944; lower limit of CI = 0.248; α = 0.990). Regarding the Bland-Altman plots, there were no clinically unacceptable errors, but a systematic underestimation of AL. CONCLUSION: Secondary reconstruction is a suitable tool for producing reliable data that allow the accurate measurement of 2TL and CDL. The option of generating these reconstructions from raw data limits the need for higher radiation doses. Nevertheless, there is an underestimation of AL using secondary reconstructions.


Assuntos
Cóclea , Ducto Coclear , Cóclea/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico , Humanos , Microtomografia por Raio-X
20.
Otol Neurotol ; 42(4): 558-565, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33492059

RESUMO

OBJECTIVE: The objective of this study is to build upon previous work validating a tablet-based software to measure cochlear duct length (CDL). Here, we do so by greatly expanding the number of cochleae (n = 166) analyzed, and examined whether computed tomography (CT) slice thickness influences reliability of CDL measurements. STUDY DESIGN: Retrospective chart review study. SETTING: Tertiary referral center. PATIENTS: Eighty-three adult cochlear implant recipients were included in the study. Both cochleae were measured for each patient (n = 166). INTERVENTIONS: Three raters analyzed the scans of 166 cochleae at 2 different time points. Each rater individually identified anatomical landmarks that delineated the basal turn diameter and width. These coordinates were applied to the elliptic approximation method (ECA) to estimate CDL. The effect of CT scan slice thickness on the measurements was explored. MAIN OUTCOME MEASURES: The primary outcome measure is the strength of the inter- and intra-rater reliability. RESULTS: The mean CDL measured was 32.84 ±â€Š2.03 mm, with a range of 29.03 to 38.07 mm. We observed no significant relationship between slice thickness and CDL measurement (F1,164 = 3.04; p = 0.08). The mean absolute difference in CDL estimations between raters was 1.76 ±â€Š1.24 mm and within raters was 0.263 ±â€Š0.200 mm. The intra-class correlation coefficient (ICC) between raters was 0.54 and ranged from 0.63 to 0.83 within raters. CONCLUSIONS: This software produces reliable measurements of CDL between and within raters, regardless of CT scan thickness.


Assuntos
Ducto Coclear , Implante Coclear , Adulto , Ducto Coclear/cirurgia , Humanos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Software
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