Influence of dental materials on artifacts and image quality in dental-dedicated MRI

To quantitatively and qualitatively evaluate artifacts from dental materials on dental-dedicated MR (ddMR) image quality.

Seventeen dental materials were shaped into cubes and placed in glass vials within a beaker filled with a homogenous solution. A cube with human enamel and dentin served as reference. Images were acquired using a ddMRI system at 0.55 T with four pulse sequences. Quantitative analysis evaluated mean voxel values (MVVs) in image center and periphery. Qualitative analysis was performed by three radiologists who assessed presence, extent, and type-void (ring or halo), blooming (blurring and loss of detail), double contour (parallel double line), truncation (bands around edges), and distortion (geometric distortion of cubes)-of artifacts.

The most common artifacts were blooming and distortion, more prevalent in 3D fat-suppressed images, especially sagittal and coronal planes. Endodontic materials showed larger MVVs in all sequences except 3D inflammation. Differences between MVVs in central and peripheral vials varied with sequence, and anatomy sequences showed greater differences for endodontic materials.

Dental materials may cause artifacts in ddMRI, mostly confined to the material or immediate surroundings. Endodontic materials tended to generate fewer artifacts than restorative materials. Artifact type and extent depend on pulse sequence.