Yutaka TAKUMI
1988-1994 MD, Hirosaki University School of Medicine
1994-1997 Residency, Hirosaki University School of Medicine
1997-1998 Visiting Research Fellow, Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo
2000-2009 Assistant Professor, Shinshu University School of Medicine
2009-2021 Associate Professor, Shinshu University School of Medicine
2021-Present Professor and Chairman, Shinshu University School of Medicine
Sessions
Cochlear implants (CIs) were initially incompatible with MRI. Recently, MRI-conditional implants that permit scanning without magnet removal or compressive bandaging have been introduced. However, MRI in CI recipients is often degraded by device-related artifacts, which may limit its clinical utility. In this study, we evaluated head MRI findings in some patients who underwent cochlear implantation at our institution and analyzed differences in artifact size across imaging modalities and sequences, together with their clinical applicability. Without magnet removal, diffusion-weighted imaging (DWI) and T2 star-weighted imaging produced larger artifacts and yielded limited diagnostic value. In contrast, T1-weighted, T2-weighted, fluid-attenuated inversion recovery (FLAIR), and heavily T2-weighted sequences allowed assessment of the contralateral side and central regions of the head, although visualization on the implanted side remained restricted. Image characteristics varied depending on both MRI modality and sequence, indicating that MRI protocols should be carefully selected according to clinical purpose and feasibility. Awareness of sequence-specific imaging characteristics is essential, and the expected diagnostic value should be considered in advance when determining MRI indications in CI patients.