Artifact on MR imaging by a dental magnetic attachment keeper: Preliminary study on a new keeper removable phantom

Aims Dental magnetic attachments with satisfactory retentive force and stability are now commercially available for dental treatment. The aim of this study was to investigate a new phantom for evaluation of the artifact on magnetic resonance (MR) imaging by a dental magnetic attachment keeper. Material and Methods We developed a new keeper removable phantom for evaluation of the artifact on MR imaging. A keeper was inserted in an acrylic pole in a PET bottle. The keeper from acrylic pole of the phantom was removable. The keeper with saline solution in the PET bottle with a head and neck coil underwent MR imaging at our university hospital. We measured the real size (unit: mm) of artifact of the phantom with the keeper using a DICOM viewer. Furthermore, the size of artifact of a patient's image with the same three keepers in the mouth was measured on the image using the DICOM viewer, too. Results In MR images of the phantom with a keeper, the maximum size of artifact on axial T1-weighted, T2-weighted and STIR images were 78 mm, 85 mm, and 67 mm, respectively. Regarding MR images of the patient with three keepers, the maximum size of artifact on axial T1-weighted, T2-weighted and STIR images were 106 mm, 111 mm and 100 mm, respectively. Conclusions We investigated a new keeper removable phantom for evaluation of the artifact on MR imaging. The phantom can be used to evaluate the artifact on MR imaging by a dental magnetic attachment keeper.