High Resolution Dental MRI – Impact of New Imaging Technique

Objectives: Dental MRI is a new, radiation free diagnostic tool. Unfortunately, the application is often limited due to poor resolution, motion artifacts and artifacts due to metallic dental materials. Here, we for the first time systematically evaluated a new MRI imaging technique to address these issues.
Methods: Artifact-volume, signal-to-noise-ratio (SNR), and image quality were assessed in vitro on a 3T MRI for multiple-slab acquisition with view angle tilting gradient, based on a sampling-perfection with application-optimized contrasts using different flip-angle evolution (SPACE) sequence (MSVAT-SPACE) and compared to a standard SPACE sequence. For evaluation of artifact reduction two implant-supported-prostheses were tested (porcelain-fused-to-metal non-precious-alloy and monolithic zirconia). Furthermore, in vivo application was tested in ten patients with various diseases (periapical lesions, periodontitis, caries and osteomyelitis).
Results: New MSVAT-SPACE imaging technique was superior to standard imaging technique in terms of artifact reduction (56 % less) and acquisition time (39 % less) while normalized SNR and in vitro image quality was not significantly different. A resolution up to 440 x 440 x 440 µm³ was achieved allowing for three dimensional reconstructions in all planes. In vivo application of high resolution Dental MRI was well tolerated by all patients. Moreover, periapical lesion identification, inflamed periodontal granulation tissue, caries and bone marrow edema were depicted excellently.
Conclusions: MSVAT-SPACE is a promising new imaging technique for Dental MRI which will help to increase dissemination and exploitation of this new promising diagnostic tool.