Effect of Implant Position on Magnetic Resonance Image Distortion
Recruitment status was: Recruiting
Patients with Neurofibromatosis type 2 (NF2) almost always develop acoustic neuromas in both ears. As a result of the tumours themselves or the treatment of the tumours, many patients become profoundly deaf in both ears. It is possible to restore a degree of hearing by placing a hearing implant in the brainstem adjacent to the hearing pathways within the brain. This is termed an auditory brainstem implant (ABI).
The aim of this study is to find the optimum head position in relation to the MRI magnet field, which would produce least area of image distortion in patients with ABIs. This will be of benefit in optimising the MR imaging in future patients with implants.
|Study Design:||Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
|Official Title:||The Effect of Changes in Head Position on Magnetic Resonance Image Distortion in Patients With Auditory Implants|
- To study the effect of magnet orientation in auditory brainstem implants/ cochlear implants in determining the size of signal void seen on MRI scanning. [ Time Frame: 1 year ]
- To identify if there is an angle at which the signal void is minimised [ Time Frame: 1 year ]
|Study Start Date:||November 2011|
|Estimated Study Completion Date:||January 2015|
|Estimated Primary Completion Date:||January 2015 (Final data collection date for primary outcome measure)|
Auditory brainstem implants (ABI) are placed against the auditory centres in the brainstem if it is not possible to implant the cochlea or if the cochlear nerve, which conveys neural signals from the cochlea to the brainstem, is damaged or absent. The latter device is usually used in patients with Neurofibromatosis type 2 (NF2) who develop bilateral benign inner ear tumours called vestibular schwannomas as well as other neurological tumours1. These patients often become bilaterally profoundly deaf either as a result of the disease or because of surgery to remove the tumours and require an ABI.
Patients with NF2 require monitoring of their tumours. In the absence of an auditory implant it is possible to use magnetic resonance imaging. This is the gold standard imaging technique as it gives excellent views of the soft tissues of head. However, there has been concern regarding the use of MRI in patients with auditory implants until recently because of potential problems such as demagnetisation of the magnet within the implant, implant magnet displacement and risk to the integrity of the implant electronics. In addition, the magnet field of the implant magnet results in imaging artefact (manifesting as a signal void) around the implant site that limits the information that can be obtained.
Please refer to this study by its ClinicalTrials.gov identifier: NCT02246231
|Contact: Hayley Brooksemail@example.com|
|Central Manchester University Hospitals NHS Foundation Trust||Recruiting|
|Manchester, Manchester (Manchester borough), United Kingdom, M13 9WL|
|Contact: Hayley Brooks 01612764902 firstname.lastname@example.org|
|Principal Investigator: Simon Lloyd|
|Principal Investigator:||Simon Lloyd||Central Manchester University Hospitals NHS Foundation Trust|