Cardiac devices overivew http://www.ajnr.org/content/38/12/2222
Non-MRI conditional cardiac device Mayo Clinic policy https://www.mayoclinic.org/medical-professionals/cardiovascular-diseases/news/new-protocols-allow-for-mri-in-selected-pacemaker-patients/mac-20430571
The NEJM study on 1509 non-MRI conditional cardiac devices https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5894885/
Cochlear implants MRI safety Johns Hopkins https://www.hopkinsmedicine.org/otolaryngology/specialty_areas/listencenter/resources/mris-at-hopkins.html