Evaluation of MRI Artifact in some selected centers in Kano Metropolis, Nigeria

Background: Magnetic Resonance Imaging (MRI) artifacts can occur due to hardware or software related problems, human physiologic phenomenon or physical restrictions. Careful study design and scanning protocols can prevent certain artifacts from occurring, but some are unavoidable. Study aims: The study aimed at evaluating MRI artifact in some selected centers in Kano metropolis, Nigeria. Methodology: A descriptive cross-sectional study was conducted involving both prospective and retrospective phases across three centres in the Kano metropolis from March 2019 to August 2019. Using the purposive sampling method, 3 centers were selected. A data capture sheet was designed for data collection. Results: Thirty five (50%) of the artifacts encountered were from the centreA, 28(40%) from the centre B, and 7(10%) from the centre C. Motion-induced artifact was the most frequently encountered artifact 26(37.1%), followed by wrap-around artifact 15(21.4%), and then frequency-induced artifact 13(18.6%). Thoracic spine MRI had the highest number of artifacts 28(40%), followed by brain 20(28.6%), and then lumbar spine 19(27.1%). Conclusion: In Kano metropolis the most encountered MRI artifact was the motion-induced artifact and thoracic spine MRI had the highest number of artifacts. The artifacts had a negative effect on image quality. Keywords: MRI artifacts; image quality; Kano metropolis.

Comparison of Cochlear Implant Magnets and Their MRI Artifact Size

Introduction. Recent developments regarding cochlear implant magnets (e.g., a bipolar diametral magnet) and refined surgical techniques (e.g., implant positioning) have had a significant impact on the relation between cochlear implants and MRIs, making the reproducible visibility of cochlea and IAC possible. MRI scanning has changed from a contraindication to a diagnostic tool. Magnet artifact size plays a central role in the visual assessment of the cochlea and IAC. Objective. The aim of this study is to compare the CI magnet-related maximum artifact sizes of various cochlea implant systems. Materials and Methods. We performed an in vivo measurement of MRI artifacts at 1.5 and 3 Tesla with three cochlear implant magnet systems (AB 3D, Medel Synchrony, and Oticon ZTI). The implant, including the magnet, was positioned with a head bandage 7.0 cm and 120° from the nasion, external auditory canal. We used a TSE T2w MRI sequence on the axial and coronal plains and compared the artifacts in two volunteers for each tesla strength. Results. Intraindividual artifact size differences between the three magnets are smaller than interindividual maximum artifact size differences. 3 T MRI scans, in comparison to 1.5 T MRI scans, show a difference between soft artifact areas. Conclusion. We observed no major difference between maximum implant magnet artifact sizes of the three implant magnet types.