Visualization of combined perio-endo lesions by means of MRI

Up to now, evidence based radiographical parameters that allow a reliable prognosis of combined perio-endo lesions before treatment, do not exist. Therapeutical changes of the periradicular tissues can be detected by means of conventional radiographic procedures only several months after performing the endodontical treatment or re-treatment. The present pilot study aims to investigate the visibility of perio-endo lesions in MRI. Materials and Methods: Three patients, in whom one or more combined perio-endo lesions were diagnosed and from whom apical or panoramic x-rays existed, were examined with a 3 tesla MRI Scanner (Magnetom Trio, Siemens, Erlangen, Germany) in the Department of Neuroradiology. The investigations were performed with special head and neck coils with a fat-saturated t2-sequence (t2_STIR_fatsat) at a voxel size of 0.6/0.6/0.6 mm. Results: The periradicular osteolysis discernable on the apical/panoramic x-rays (periodontal space width of 3-5 mm at a magnification of 1.5) could be detected on the MR Images as an opaque periradicular cuff. The width of the periodontal space ranged between 1.8 mm for two patients and 5.6 mm for the third one. Conclusions: Perio-endo lesions can be detected in MR Images. In order to assess therapeutical changes after endodontical treatment or re-treatment in MR Images earlier than in conventional x-rays, further investigations need to be performed. Keywords: Perio-endo lesions, dental MRI, bone loss, periodontitis, periodontal space