Magnetic resonance tomography in the diagnosis of osteomyelitis of the mandible

Purpose: A prospective study of the value of MRI in the diagnosis of osteomyelitis of the mandible with special reference to the suitability of different MR sequences. Material and Methods: In 13 patients, average age 55 years (12-82), with clinical suspicion of osteomyelitis of the mandible, 18 MRI examinations were carried out (STIR, TSE T2, proton and SE T1 weighted scans with and without contrast, slice thickness 3.5 to 6 mm). Image quality of the sequences was evaluated as well as the suitability of the various sequences for showing the lesion, its location and extent. Activity of the osteomyelitis was judged by the degree of contrast uptake and was correlated with 3-phase bone scintigraphy and with histological findings. Results: In 9 of the 14 cases the findings on MRI and of the scintigraphy agreed with the histology. In two patients the activity of the inflammatory process was exaggerated by the MRI. In another follow-up examination it was slightly underestimated. All lesions were shown to be highly active by the histology were recognished as such by MRI. For the localisation and recognition of the extent of the inflammatory processes STIR sequences and T1 weighted non-enhanced SE sequences proved the most suitable. Contrast medium is essential to evaluate the inflammatory activity. Conclusion: MRI is a sensitive diagnostic method; it is as good as 3-phase bone scintigraphy in demonstrating osteomyelitis of the mandible and of its activity but is superior for showing the pathological anatomy. (orig.)