Imaging findings of bisphosphonate-related osteonecrosis of the jaw with emphasis on early magnetic resonance imaging findings

PURPOSE: To describe the imaging findings of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with emphasis on early magnetic resonance imaging (MRI) findings. MATERIALS AND METHODS: The medical records and computed tomography, MRI, and bone scintigraphy images of 5 female and 1male patients (n = 6) between the ages of 49 and 79 years (mean age, 70 years) who had a diagnosis of BRONJ were retrospectively reviewed, and temporal changes in imaging features were noted. RESULTS: The earliest MRI finding was the loss of the normal T1 hyperintensity of fatty marrow in the mandible and maxilla. The MRI findings of more advanced BRONJ included bone destruction, soft tissue edema and enhancement, inferior alveolar nerve thickening, and pterygoid muscle swelling and enhancement. On computed tomography, sclerosis and subtle lucencies (widening) of the periodontal ligament and cortex and around the apices of the teeth in the early stage, and osteolytic bone lesions, cortical disruption, and frank bone fragmentation in the later stages were observed. Bone scintigraphy showed increased uptake early in the disease. CONCLUSIONS: Osteonecrosis of the mandible and maxilla occurs as a complication of bisphosphonate treatment of bone metastasis and osteoporosis and typically manifests after a dental procedure. Magnetic resonance imaging and bone scintigraphy findings may precede clinical symptoms and mimic metastatic disease.