scholarly journals Variation of the Anatomy of the Cochlea and Cochlear Duct Length (CDL) in Patients who Underwent Standard Cochlear Implantation – Radioanatomy with a New Tablet-Based Software

2021 ◽  
Author(s):  
JL. Spiegel ◽  
D Polterauer ◽  
J-M Hempel ◽  
M Canis ◽  
J Spiro ◽  
...  
Keyword(s):  
Cochlear Implantation ◽  
Cochlear Duct ◽  
Cochlear Duct Length

scholarly journals Cone beam CT for perioperative imaging in hearing preservation Cochlear implantation – a human cadaveric study

2019 ◽  
Vol 48 (1) ◽  
Author(s):  
Kayvan Nateghifard ◽  
David Low ◽  
Lola Awofala ◽  
Dilakshan Srikanthan ◽  
Jafri Kuthubutheen ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Cochlear Implantation ◽  
Lateral Wall ◽  
Cone Beam ◽  
Insertion Depth ◽  
Cochlear Duct ◽  
Low Radiation Dose ◽  
A Value ◽  
Cochlear Duct Length ◽  
Temporal Bones

Abstract Background Knowledge of the cochlear implant array’s precise position is important because of the correlation between electrode position and speech understanding. Several groups have provided recent image processing evidence to determine scalar translocation, angular insertion depth, and cochlear duct length (CDL); all of which are being used for patient-specific programming. Cone beam computed tomography (CBCT) is increasingly used in otology due to its superior resolution and low radiation dose. Our objectives are as followed: Validate CBCT by measuring cochlear metrics, including basal turn diameter (A-value) and lateral wall cochlear duct length at different angular intervals and comparing it against microcomputed CT (uCT).Explore the relationship between measured lateral wall cochlear duct length at different angular intervals and insertion depth among 3 different length electrodes using CBCT. Methods The study was performed using fixed human cadaveric temporal bones in a tertiary academic centre. Ten temporal bones were subjected to the standard facial recess approach for cochlear implantation and imaged by CBCT followed by uCT. Measurements were performed on a three-dimensional reconstructed model of the cochlea. Sequential insertion of 3 electrodes (Med-El Flex24, 28 and Soft) was then performed in 5 bones and reimaged by CBCT. Statistical analysis was performed using Pearson’s correlation. Results There was good agreement between CBCT and uCT for cochlear metrics, validating the precision of CBCT against the current gold standard uCT in imaging. The A-value recorded by both modalities showed a high degree of linear correlation and did not differ by more than 0.23 mm in absolute values. For the measurement of lateral wall CDL at various points along the cochlea, there was a good correlation between both modalities at 360 deg and 720 deg (r = 0.85, p < 0.01 and r = 0.79, p < 0.01). The Flex24 electrode displayed consistent insertion depth across different bones. Conclusions CBCT reliably performs cochlear metrics and measures electrode insertion depth. The low radiation dose, fast acquisition time, diminished metallic artifacts and portability of CBCT make it a valid option for imaging in cochlear implant surgery.

scholarly journals The Effect of Cochlear Size on Cochlear Implantation Outcomes

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jafri Kuthubutheen ◽  
Amandeep Grewal ◽  
Sean Symons ◽  
Julian Nedzelski ◽  
David Shipp ◽  
...  
Keyword(s):  
Cochlear Implantation ◽  
Outer Wall ◽  
X Rays ◽  
Speech Discrimination ◽  
Insertion Depth ◽  
Basal Diameter ◽  
Cochlear Duct ◽  
Significant Difference ◽  
Cochlear Duct Length ◽  
Electrode Insertion

Objectives. To determine if cochlear duct length and cochlear basal diameter, measured using routinely available radiology software, affect hearing outcomes after cochlear implantation with two different length electrodes. Methods. 55 patients who received a Med-El Flex electrode were retrospectively reviewed. 34 patients received the Flex 31 electrode (31mm) and 21 patients received the Flex 28 electrode (28mm). Preoperative high-resolution CT scans of the temporal bone were reformatted in the axial and coronal plane. The basal diameter of the cochlear (A-value) and the outer-wall lengths of the cochlear duct were measured using readily available imaging software. Postoperative plane X-rays were used to determine the degree of electrode insertion and the number of electrodes within the cochlea and speech discrimination scores at 6 months were evaluated. Results. The cochlear metrics obtained were comparable with those previously published in the literature. There was no significant difference in the degree of insertion or speech outcomes between the two electrode lengths. However, when the group who had received the shorter electrode were analysed, there was an association seen between both cochlear duct length and cochlear diameter and speech outcomes. Conclusions. Cochlear size may be a factor in determining speech outcomes that cannot be explained solely by insertion depth or degrees of insertion. Further studies are required to determine if cochlear duct length is an independent predictor of speech outcomes.

CT-scan contouring technique allows for direct and reliable measurements of the cochlear duct length: implication in cochlear implantation with straight electrode-arrays

2019 ◽  
Vol 276 (8) ◽  
pp. 2135-2140 ◽  
Author(s):  
Thi Hau Vu ◽  
Chiara Perazzini ◽  
Mathilde Puechmaille ◽  
Aurélie Bachy ◽  
Aurélien Mulliez ◽  
...  
Keyword(s):  
Ct Scan ◽  
Cochlear Implantation ◽  
Electrode Arrays ◽  
Cochlear Duct ◽  
Cochlear Duct Length

Computed Tomography Estimation of Cochlear Duct Length Can Predict Full Insertion in Cochlear Implantation

2016 ◽  
Vol 37 (3) ◽  
pp. 223-228 ◽  
Author(s):  
James D. A. Johnston ◽  
Daniel Scoffings ◽  
Mark Chung ◽  
David Baguley ◽  
Neil P. Donnelly ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cochlear Implantation ◽  
Cochlear Duct ◽  
Cochlear Duct Length

Mapping Cochlear Duct Length to Electrically Evoked Compound Action Potentials in Cochlear Implantation

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Robert Mlynski ◽  
Adele Lüsebrink ◽  
Tobias Oberhoffner ◽  
Soenke Langner ◽  
Nora M. Weiss
Keyword(s):  
Cochlear Implantation ◽  
Action Potentials ◽  
Cochlear Duct ◽  
Compound Action Potentials ◽  
Cochlear Duct Length ◽  
Compound Action

scholarly journals Cochlear Duct Length Measurements in Computed Tomography and Magnetic Resonance Imaging Using Newly Developed Techniques

OTO Open ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 2473974X2110453
Author(s):  
Johannes Taeger ◽  
Franz Tassilo Müller-Graff ◽  
Lukas Ilgen ◽  
Phillip Schendzielorz ◽  
Rudolf Hagen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Cochlear Implantation ◽  
Tertiary Care ◽  
Resonance Imaging ◽  
Cochlear Duct ◽  
Tertiary Care Medical Center ◽  
Length Measurements ◽  
Cochlear Duct Length

Objective Growing interest in measuring the cochlear duct length (CDL) has emerged, since it can influence the selection of cochlear implant electrodes. Currently the measurements are performed with ionized radiation imaging. Only a few studies have explored CDL measurements in magnetic resonance imaging (MRI). Therefore, the presented study aims to fill this gap by estimating CDL in MRI and comparing it with multislice computed tomography (CT). Study Design Retrospective data analyses of 42 cochleae. Setting Tertiary care medical center. Methods Diameter (A value) and width (B value) of the cochlea were measured in HOROS software. The CDL and the 2-turn length were determined by the elliptic circular approximation (ECA). In addition, the CDL, the 2-turn length, and the angular length were determined via HOROS software by the multiplanar reconstruction (MPR) method. Results CDL values were significantly shorter in MRI by MPR ( d = 1.38 mm, P < .001) but not by ECA. Similar 2-turn length measurements were significantly lower in MRI by MPR ( d = 1.67 mm) and ECA ( d = 1.19 mm, both P < .001). In contrast, angular length was significantly higher in MRI ( d = 26.79°, P < .001). When the values were set in relation to the frequencies of the cochlea, no clinically relevant differences were estimated (58 Hz at 28-mm CDL). Conclusion In the presented study, CDL was investigated in CT and MRI by using different approaches. Since no clinically relevant differences were found, diagnostics with radiation may be omitted prior to cochlear implantation; thus, a concept of radiation-free cochlear implantation could be established.

Assessment of Inter- and Intra-Rater Reliability of Tablet-Based Software to Measure Cochlear Duct Length

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Shayna P. Cooperman ◽  
Ksenia A. Aaron ◽  
Ayman Fouad ◽  
Emma Tran ◽  
Nikolas H. Blevins ◽  
...  
Keyword(s):  
Rater Reliability ◽  
Cochlear Duct ◽  
Cochlear Duct Length

A study on modelling cochlear duct mid-scalar length based on high-resolution computed tomography, and its effect on peri-modiolar and mid-scalar implant selection

2019 ◽  
Vol 133 (09) ◽  
pp. 764-769
Author(s):  
G Pamuk ◽  
A E Pamuk ◽  
A Akgöz ◽  
E Öztürk ◽  
M D Bajin ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Round Window ◽  
Chronic Otitis Media ◽  
Lateral Wall ◽  
High Resolution Computed Tomography ◽  
Cochlear Duct ◽  
Implant Selection ◽  
Cochlear Duct Length ◽  
Implant Length

AbstractObjectiveTo determine cochlear duct mid-scalar length in normal cochleae and its role in selecting the correct peri-modiolar and mid-scalar implant length.MethodsThe study included 40 patients with chronic otitis media who underwent high-resolution computed tomography of the temporal bone. The length and height of the basal turn, mid-modiolar height of the cochlea, mid-scalar and lateral wall length of the cochlear duct, and the ‘X’ line (the largest distance from mid-point of the round window to the mid-scalar point of the cochlear canal) were measured.ResultsCochlear duct lateral wall length (28.88 mm) was higher than cochlear duct mid-scalar length (20.08 mm) (p &lt; 0.001). The simple linear regression equation for estimating complete cochlear duct length was: cochlear duct length = 0.2 + 2.85 × X line.ConclusionUsing the mid-scalar point as the reference point (rather than the lateral wall) for measuring cochlear duct mid-scalar length, when deciding on the length of mid-scalar or peri-modiolar electrode, increases measurement accuracy. Mean cochlear duct mid-scalar length was compatible with peri-modiolar and mid-scalar implant lengths. The measurement method described herein may be useful for pre-operative peri-modiolar or mid-scalar implant selection.

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