ABSTRACT
Objective: This study aims to measure the complete and two-turn cochlear duct lengths in a Filipino population using archived CT scan images.Methods: Design: Retrospective Review of Records Setting: Tertiary Government Training Hospital Participants: CT Scan Images of 255 patientsCochlear images of patients who underwent cranial, facial, orbital, paranasal sinus and temporal bone CT scans from January 2019 to December 2019 were analyzed. Coronal oblique images from 3D multiplanar reconstructions were obtained and a single linear measurement ('A' value) was used as the spiral coefficient to calculate the complete cochlear duct length (CDL) and two-turn length (2TL).Results: A total of 510 cochlear images were obtained from the CT scan images of 255 subjects (143 males, 112 females aged 1 to 81 years; mean age = 47 years). The mean 'A' value was 8.81 mm (SD = 0.20). The mean complete cochlear duct length was 32.68 mm (31.01 mm - 35.50 mm; SD = 0.834) while the mean two-turn cochlear duct length was 29.61 mm (28.14 mm - 32.08 mm; SD = 0.732). The complete and two-turn cochlear duct lengths in males were found to be significantly longer than in females (p = .001). No significant difference was found between cochlear measurements for left and right ears.Conclusion: The mean complete cochlear duct length among Filipinos in our study measures 32.68 mm while the mean two-turn cochlear duct length measures 29.61mm. Both complete and two-turn cochlear duct lengths were longer among Filipino males than among females.
Subject(s)
Humans , Male , Female , CochleaABSTRACT
Objective@#This study aims to measure the complete and two-turn cochlear duct lengths in a Filipino population using archived CT scan images.
Subject(s)
CochleaABSTRACT
Abstract Introduction Successful cochlear implantation requires an appropriate insertion depth of the electrode, which depends on cochlear duct length CDL). The CDL can vary due to ethnic factors. Objective The objective of the current study was to determine the CDL in an Indian adult cadaveric population. Methods The present was a cadaveric study using the temporal bones obtained after permission of the Institutional Review Board. The temporal bones were subjected to high-resolution computed tomography (HRCT), and the double oblique reformatted CT images were reconstructed through the basal turn of the cochlea. The reformatted images were then viewed in the minimum-intensity projection (minIP) mode, and the 'A' value (the diameter of the basal turn of the cochlea) was calculated. The CDL was then measured using the formula CDL = 4.16A - 4 (Alexiades et al). The data analysis was performed using the Microsoft Excel software, version 2016. Results A total of 51 temporal bones were included for imaging analysis. The CDL varied from 27.6 mm to 33.4 mm, with a mean length of 30.7 mm. There was no statistically significant difference between the two sides. Conclusion The CDL can be calculated with preoperative high-resolution CT, and can provide a roadmap for effective cochlear implant electrode insertion. The population-based anatomical variability needs to be taken into account to offer the most efficient and least traumatic insertion of the electrode.
ABSTRACT
A audiometria de altas frequências (AAF) é um exame audiológico importante na detecção precoce de perdas auditivas por lesões na base do ducto coclear. Nos últimos anos, a sua utilização foi facilitada pelo fato de os audiômetros comercializados passarem a incorporar frequências superiores a 8 kHz. Porém, existem diferenças relacionadas aos equipamentos utilizados, às metodologias empregadas e/ou aos resultados e interpretação. Assim, o objetivo deste artigo foi analisar a produção científica nacional sobre a aplicação clínica com AAF, para compreender sua utilização atual. Foram pesquisados textos publicados e indexados nas bases de dados LILACS, SciELO e Medline, num período de tempo de dez anos, utilizando como descritor audiometria de altas frequências/high-frequency audiometry. Encontraram-se 24 artigos científicos nacionais utilizando AAF, cuja população avaliada, em sua maioria, apresentava de 18 a 50 anos de idade; 13 dos estudos determinaram os limiares utilizando como referência decibel nível de audição (dBNA); alguns estudos realizaram a comparação dos limiares auditivos tonais entre grupos para definir a normalidade; os autores relataram diferenças significativas nos limiares auditivos de altas frequências entre as idades. A AAF é utilizada na clínica audiológica para identificação precoce de alterações auditivas e no acompanhamento da audição de sujeitos expostos a drogas ototóxicas e/ou agentes otoagressores.
High-frequency audiometry (HFA) is an important audiological test for early detection of hearing losses caused by leasions in the base of the cochlear duct. In recent years, its use was facilitated because audiometers began to identify frequencies higher than 8 kHz. However, there are differences related to the equipment used, the methodologies followed, and/or to the results and their interpretation. Therefore, the aim of this study was to analyze the national scientific production regarding HFA clinical application, to better understand its current use. Articles published and indexed in LILACS, SciELO and Medline databases in the last ten years were researched, using as keyword audiometria de alta frequência/high-frequency audiometry. Twenty-four Brazilian scientific papers using HFA were found; most studies evaluated participants with ages ranging from 18 to 50 years; 13 studies used decibel hearing level (dBHL) to determine the thresholds; a few studies compared tonal auditory thresholds between groups to define normality; the authors reported significant differences in high frequency auditory thresholds among age ranges. HFA is used in audiological clinic for early identification of auditory alterations and in the auditory follow-up of subjects exposed to ototoxic drugs and/or otoagressive agents.
Subject(s)
Audiometry, Pure-Tone , Cochlear Duct , Hearing , Hearing Loss/diagnosisABSTRACT
The authors observed the development of the organ of Corti in the temporal bones of 64 human fetuses of various fetal ages by means of comparing celloid sections with surface preparations. The organ of Corti just begins to appear in the second month. Most rapid development occurs in the period from the third to the fifth month. Afterwards, the principal structure of the organ of Corti tends to be stable with no further major changes, except for the differentiation and maturation of the intracellular components. In the fifth month, the major part of the higher columnar epithelial cells on the inner Side of the tunnel begins to degenerate and disintegrate before the formation of the inner spiral sulcus. But a few epithelial cells turn into large wandering cells. The authors discussed the characteristics, function and possible transformation of the wandering cells and compared them with essentially similar cells that appear in the developing central nervous system.