RESUMO
OBJECTIVE: Three-phase bone scintigraphy has been used for the diagnosis of osteomyelitis in some regions of the body. However, its utility in patients with chronic osteomyelitis of the mandible (COM) has been reported only occasionally and the significance has not been fully examined. The aim of this study was to investigate what can be identified from each phase of the three-phase bone scintigraphy in patients with COM. METHODS: Three-phase bone scintigraphy using (99m)Tc-labeled phosphonates was performed [96 s (phase 1), 5 min (phase 2) and 3 h (phase 3)] in 15 patients with COM. An increase in accumulation was regarded as a positive result in visual analysis. We investigated the positive ratio of each phase, including in the classification of the disease type, serum white blood cell count, C-reactive protein value and morbidity period. We also calculated the uptake ratio relative to the contralateral side using mean and maximum counts of the region of interest in semiquantitative analysis and investigated the correlation between the uptake ratios of each phase. RESULTS: The positive ratio of phases 2 and 3 was 100% and higher than that of phase 1 (33.3%, p = 0.0001). Almost all patients with a positive result in phase 1 had the osteolytic type (5/6). The extent of increased uptake on phase 3 images was similar to that of phase 2 images. The uptake ratio of phase 2 correlated with that of phase 3 (mean: r = 0.88, p < 0.0001, max: r = 0.78, p = 0.0006), but was not as high as that of phase 3. CONCLUSIONS: The phase 1 results reflect hyperemia and have a strong potential to diagnose the disease type. Phase 3 alone is sufficient to diagnose the disease and the extent of lesion in patients with highly suspected COM.