Efficacy of diffusion-weighted magnetic resonance imaging in the diagnosis of osteomyelitis of the mandible

Objective. This retrospective cohort study aimed to determine the diagnostic utility of apparent diffusion coefficient (ADC) values in the quantitative evaluation of mandibular osteomyelitis. Methods. We analyzed the records of 70 patients aged 30 to 90 years, with and without osteomyelitis, who underwent magnetic resonance imaging at the Nihon University School of Dentistry between April 2017 and March 2019. The mean ADC of bone marrow of patients without osteomyelitis and those with acute and chronic osteomyelitis of the mandible were calculated. Differences in ADC overall and in pair-wise comparisons were analyzed. Correlations with patient age were also calculated. Results. The mean ADC values in the nonosteomyelitis, acute osteomyelitis, and chronic osteomyelitis groups were 0.87 +/- 0.15 x 10(-3), 1.24 +/- 0.11 x 10(-3), and 1.07 +/- 0.13 x 10(-3) mm(2)/s, respectively (P < .001 for all pair-wise comparisons). Receiver operating characteristic curve analysis revealed an ADC cut-off of 0.98 for osteomyelitis. Diagnostic values for predicting osteomyelitis were >= .81. No correlations of osteomyelitis with age were found. Conclusions. The ADC was significantly higher in the osteomyelitis groups than in the nonosteomyelitis group. This suggests that ADC may be a useful parameter for quantitative evaluation of mandibular osteomyelitis.