CT and MRI for Pre-Operative Cochlear Imaging

July 25, 2022 updated by: Mohamed Abdel-Tawab Mohamed, Assiut University

Role of Multislice Computed Tomography and Magnetic Resonance Imaging in Preoperative Cochlear Implant Evaluation

This study investigates the role of the preoperative computed tomography (CT) and magnetic resonance imaging (MRI) before cochlear implants and their role in selecting suitable patients for surgery.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Cochlear implant is the treatment of choice for deep sensorineural hearing loss, notably in those patients for whom conventional amplification devices do not provide significant clinical improvement. Imaging plays an important role in the workup of cochlear implant candidates not only to identify inner ear congenital and acquired abnormalities or cochlear nerve anomalies but also to detect temporal bone abnormalities that may be encountered during surgery and may alter surgical approach.

Some variations are potential surgical hazards that may lead to problems during the surgery and may alert the surgeon regarding potential surgical dangers and complications.

The radiologist and surgeon must be familiar with these imaging findings. Both computed tomography and magnetic resonance imaging should be used as they delineate, in different manners, cochlear and middle ear anatomy as well as other anatomical variants.

Mastoid pneumatization is important for planning the surgery. It is classified into pneumatic, diploic, sclerotic, and mixed. Effusion of the middle ear cleft should also be reported.

Korner's septum divides the mastoid process into a superficial squamous portion and a deep petrous portion. It may mislead the surgeon to the mastoid antrum during surgery. Mastoid emissary veins participate in extracranial venous drainage of the posterior fossa dural sinuses. Most of them disappear, however, some persist and enlarge.

Low lying dura represents difficulty to access the aditus, lateral semicircular canal, and posterior tympanotomy. It is often associated with sclerotic mastoid. Posterior tympanotomy is a well known otologic procedure that allows surgeons to access the middle ear cavity. The surgeon opens a window in the posterior wall of the middle ear in the angle between the chorda tympani and the mastoid part of the facial nerve. Laterally or anteriorly positioned mastoid part of the facial nerve may hinder the access to the facial recess or may even force the surgeon to change his approach.

The sigmoid sinus passes along the posteromedial border of the mastoid air cells. An anteriorly located sinus produces a deep bulge in the mastoid and may reach the posterior wall of the external auditory canal being separated from it only by a thin bony plate.

Jugular bulb variations are common, the roof of a normal jugular bulb lies either at or slightly below the level of the external auditory canal floor and is separated from the middle ear cavity by the thin bony sigmoid plate. The average width of the jugular bulb is 1 cm. A jugular bulb larger than 1 cm is called a giant or mega jugular bulb. A jugular bulb that extends over the basal turn of the cochlea or abuts the round window is called a high riding jugular bulb. Dehiscence of the sigmoid plate with upward protrusion of the bulb into the posterior hypotympanum is called a dehiscent jugular bulb, which may obliterate a round window niche.

The aberrant internal carotid artery is an enlarged inferior tympanic artery that occurs as a result of agenesis or underdevelopment of the cervical segment of the internal carotid artery. It runs along the medial aspect of the middle ear coursing anteriorly across the cochlear promontory to join the horizontal carotid canal through a dehiscence in the carotid plate.

Cochlear duct patency and axis, patency of the round window niche and the patent even caliber of the cochlea must be adequately evaluated by both computed tomography and magnetic resonance imaging. Otospongiotic foci compromise the insertion of the cochlear implant electrode if they occlude the round window niche or cochlear duct. Labyrinthitis ossificans may partially or completely obliterate cochlear lumen. Fibrosis may precede ossification and areas of fibrosis and ossification may coexist. Cochlear ossification with luminal obstruction is not a contraindication for implantation, however, it is important to be identified preoperatively.

Vestibular aqueduct (VA) is considered dilated if its width is greater than the width of the posterior SCC or if its midpoint width is greater than 1.5 mm. Computed tomography shows dilatation of the VA only whereas magnetic resonance imaging shows the dilatation of the VA and of the endolymphatic sac.

Study Type

Observational

Enrollment (Anticipated)

50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Egypt
      • Assiut, Egypt, 71515
        • Recruiting
        • Assiut University
        • Contact:
          • Mohamed Salah, MSc
          • Phone Number: +201003975007

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The study will be performed in Assiut University Hospital, Department of Radiology during the period from May 2019 to May 2021, and will include 50 patients from different age groups and both sex who will be clinically diagnosed as having severe to profound SNHL and fulfill the criteria for the cochlear implant.

Description

Inclusion Criteria:

  • Patients fulfilled criteria for cochlear implant including audiological criteria (as bilateral profound hearing loss not benefiting from hearing aid) and phoniatric criteria as IQ (using Stanford Binet intelligence scale) more than 80 with no medical, surgical, or radiological contraindication for surgery
  • Family motivation and commitment for audiologic and phoniatric rehabilitation and follow up
  • Confirmation of the presence of cochlear nerve using preimplant MRI.

Exclusion Criteria:

  • Patient who did not fulfill the criteria for indicating cochlear implant surgery
  • Patients with no records of preoperative investigations
  • Patients with major dysplasia or aplasia of the cochlea as a common cavity.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Only
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
"cochlear implantation" group
"cochlear implantation" group: patients undergoing cochlear implantation between December 2019 and December 2021in the ENT department of Assiut university hospital.
Diagnostic test: Computed Tomography and Magnetic resonance imaging
Preoperative imaging for patients undergoing cochlear implants

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Identifying contraindications for cochlear implant
Time Frame: Day 0

Identifying contraindications for cochlear implant including

  • cochlear nerve aplasia (evidenced by MRI)
  • cochlear and/or labyrinthine aplasia
  • absence of the internal auditory canal and of the petrous apex bone
  • absence or fusion of the ossicles
Day 0

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assiut University

Investigators

  • Study Chair: Abdelkarim H Abdallah, Professor, Assiut University
  • Study Director: Hazem A Yousef, MD, Assiut University
  • Study Director: Reham A Mahmoud, MD, Assiut University
  • Principal Investigator: Mohamed A Mohamed, MD, Assiut University
  • Study Director: Mohamed Salah sadek Ibrahim, Master, Assiut University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 1, 2019

Primary Completion (Anticipated)

November 1, 2023

Study Completion (Anticipated)

December 1, 2023

Study Registration Dates

First Submitted

October 16, 2019

First Submitted That Met QC Criteria

October 16, 2019

First Posted (Actual)

October 18, 2019

Study Record Updates

Last Update Posted (Actual)

July 26, 2022

Last Update Submitted That Met QC Criteria

July 25, 2022

Last Verified

July 1, 2022

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Imaging in Cochlear implant

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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