Magnetic Resonance Imaging at 1.5 Tesla With a Cochlear Implant Magnet in Place: Image Quality and Usability

Jeffrey D. Sharon, Benjamin G. Northcutt, Nafi Aygun, Howard W. Francis

Research output: Contribution to journalArticle

Abstract

OBJECTIVE:: To study the quality and usability of magnetic resonance imaging (MRI) obtained with a cochlear implant magnet in situ. STUDY DESIGN:: Retrospective chart review. SETTING:: Tertiary care center. PATIENTS:: All patients who underwent brain MRI with a cochlear implant magnet in situ from 2007 to 2016. INTERVENTION(S):: None. MAIN OUTCOME MEASURE(S):: Grade of view of the ipsilateral internal auditory canal (IAC) and cerebellopontine angle (CPA). RESULTS:: Inclusion criteria were met by 765 image sequences in 57 MRI brain scans. For the ipsilateral IAC, significant predictors of a grade 1 (normal) view included: absence of fat saturation algorithm (p?=?0.001), nonaxial plane of imaging (p?=?0.01), and contrast administration (p?=?0.001). For the ipsilateral CPA, significant predictors of a grade 1 view included: absence of fat saturation algorithm (p?=?0.001), high-resolution images (p?=?0.001), and nonaxial plane of imaging (p?=?0.001). Overall, coronal T1 high-resolution images produced the highest percentage of grade 1 views (89%). Fat saturation also caused a secondary ring-shaped distortion artifact, which impaired the view of the contralateral CPA 52.7% of the time, and the contralateral IAC 42.8% of the time. MRI scans without any usable (grade 1) sequences had fewer overall sequences (N?=?4.3) than scans with at least one usable sequence (N?=?7.1, p?=?0.001). CONCLUSION:: MRI image quality with a cochlear implant magnet in situ depends on several factors, which can be modified to maximize image quality in this unique patient population.

Original languageEnglish (US)
JournalOtology and Neurotology
DOIs
StateAccepted/In press - Aug 12 2016

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ASJC Scopus subject areas

  • Medicine(all)
  • Otorhinolaryngology
  • Sensory Systems
  • Clinical Neurology

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