A method for measuring the length of the coclea through magnetic resonance imaging

Sobrinho, Fernando Pochini; Lazarini, Paulo Roberto; Yoo, Hea Jung; Júnior, Luiz de Abreu; Meira, Altino de Sá

doi:10.1016/s1808-8694(15)30788-6

Cited by 6 publications

(4 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Divide the spiral canal into a number of section and to measure each one; adding up these values yielded the total length of cochlea. 1 The rulers has predefined 2.0, 1.5 and 1.0 mm markings and are placed over the cochlear images for measurements. Many rulers are required for each image until reaching the apex of the cochlea.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Measurement of Cochlear Dimensions by 3d Ct-Mri and Its Utility in Cochlear Implants Surgery

Solanki¹,

Digge²,

Viswakarma³

et al. 2017

jebmh

View full text Add to dashboard Cite

BACKGROUND We presented role of MDCT and high-field MRI in cochlear dimension before the cochlear implantation. In our institute, we used combo modality as HRCT and high-field MRI rather to use single modality for complete workup and for the selection of proper size electrode array. The aim of the study is to correlate the cochlear dimensions using CT/MRI with-(1) Intraoperative surgical findings/difficulties. (2) Preoperative electrode array option selection. MATERIALS AND METHODS MDCT and 1.5 Tesla MRI machine was used to scan the patients. Patients screened and operated at B.J. Medical College and Civil Hospital, Ahmedabad, Gujarat. 30 patients were taken within period of 2 years from March 2009 to April 2011. All the patients underwent CT and MRI study. Cochlear implant (MED-EL, Austria) was used for this study. Each scan was obtained on a 16-section spiral CT (GE, bright speed). The studies were performed with the following parameters-0.75-mm collimation, 0.625-mm section thickness, 140 kVp, 120 mAs, pitch of 0.8, a 15-cm field of view and a 512 x 512 matrix. The initial data sets were then reconstructed at 0.1 mm intervals. All 15 patients also underwent MRI (GE Signa HDx 1.5T series) examination for internal auditory canal in whom FIESTA sequence was taken with flip angle 65 degrees, slice thickness 0.8 mm, matrix 256 x 320. RESULTS Thirty cases were taken for the study. Twenty patients were completely suitable for standard electrode. Six patients needed the use of insertion test device before the actual insertion of active electrode. In 3 patients, split electrode was kept as backup implant, but was finally not needed. One patient had common cavity cochlea who refused surgery because of variable outcome. Three patients had high jugular bulb. Six patients had rotated cochlea. One patient had dehiscent facial nerve at 2 nd genu. CONCLUSION Multidetector volumetric CT scanner with 3D reconstruction and higher strength MRI provide soft tissue and bony detail with very high resolution for cochlea and also helps in minimise the intraoperative difficulties and overcoming it and also help in assessing the involvement of adjacent critical structures like internal carotid artery, jugular bulb and facial nerve.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Many rulers are required for each image until reaching the apex of the cochlea. The first six ruler (R1 to R6) measured 2 mm, the next rulers has smaller sizes to measure the cochlear contours (R7 to R14) 1 (Figure 3).…”

Section: Discussionmentioning

confidence: 99%

Measurement of Cochlear Dimensions by 3d Ct-Mri and Its Utility in Cochlear Implants Surgery

Solanki¹,

Digge²,

Viswakarma³

et al. 2017

jebmh

View full text Add to dashboard Cite

show abstract

“…There have been limited studies evaluating MR imaging for similar objectives. 14,15 One of these studies measured the intraobserver and interobserver reliability of the A-value, while the other study used the spiral ganglion as the measurement target, and only 1 observer performed the measurements. Multiple studies have been performed with CT, 3 and most measured the A-value and rarely dealt with the reproducibility of the method.…”

Section: Accuracy and Reliability Of 3d Cochlear Length Measurementsmentioning

confidence: 99%

Measuring 3D Cochlear Duct Length on MRI: Is It Accurate and Reliable?

Eser¹,

Atalay²,

Doğan³

et al. 2021

AJNR Am J Neuroradiol

View full text Add to dashboard Cite

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, À0.11 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 À0.59 mm (95% CI, À1.00 to À0.20 mm). An intraclass correlation coefficient value of 0.90 (95% CI, 0.84À0.94) for CT and 0.69 (95% CI, 0.46À0.82) 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 imag-ingÀbased 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.

show abstract

“…As well, magnetic resonance imaging (MRI) may be applied pre-operatively to quantify the geometric characteristics of the fluid-filled spaces in the cochlea for coregistration with post-operative CT data in an attempt to increase the level of detail in the 3D description of the cochlear structures. MRI can be used to determine modiolar area and volume (Kendi et al 2004;Naganawa et al 1999), volume of the labyrinth (Kendi et al 2004;Melhem et al 1998;Neri et al 2000), cochlear nerve preservation (Ketten et al 1998b;Lane et al 2007) and length of the cochlea (Sobrinho et al 2009), which are all parameters that may either be incorporated into the 3D geometry or used to validate the integrity of a model representation of a cochlea. MRI is specifically used for evaluating luminal ossification and inner ear patency before cochlear implantation (Chaturvedi et al 2006;Fishman 2012;Murugasu et al 1999;Seitz et al 2001;Taha et al 2015;Vaid et al 2014) which are important factors to consider when developing user-specific models.…”

Section: Opfos An Optical Sectioning Technique and μCt That Is A Radmentioning

confidence: 99%

Three-dimensional models of cochlear implants: A review of their development and how they could support management and maintenance of cochlear implant performance

Hanekom

2016

Network: Computation in Neural Systems

View full text Add to dashboard Cite

Three-dimensional (3D) computational modeling of the auditory periphery forms an integral part of modern-day research in cochlear implants (CIs). These models consist of a volume conduction description of implanted stimulation electrodes and the current distribution around these, coupled with auditory nerve fiber models. Cochlear neural activation patterns can then be predicted for a given input stimulus. The objective of this article is to present the context of 3D modeling within the field of CIs, the different models, and approaches to models that have been developed over the years, as well as the applications and potential applications of these models. The process of development of 3D models is discussed, and the article places specific emphasis on the complementary roles of generic models and user-specific models, as the latter is important for translation of these models into clinical application.

show abstract

A method for measuring the length of the coclea through magnetic resonance imaging

Cited by 6 publications

References 15 publications

Measurement of Cochlear Dimensions by 3d Ct-Mri and Its Utility in Cochlear Implants Surgery

Measurement of Cochlear Dimensions by 3d Ct-Mri and Its Utility in Cochlear Implants Surgery

Measuring 3D Cochlear Duct Length on MRI: Is It Accurate and Reliable?

Three-dimensional models of cochlear implants: A review of their development and how they could support management and maintenance of cochlear implant performance

Contact Info

Product

Resources

About