Diagnostic value of computed tomography, magnetic resonance imaging, and scintigraphy in diagnosing actinomycosis of the mandible

Mandibular actinomycosis is an uncommon disease caused by Actinomyces israelii. Actinomycosis infection typically manifests as a chronic disease resulting in multiple abscesses, firm soft tissue mass, and presence of sulfur granules in exudates or tissues. A few reports have provided imaging findings of actinomycosis in the head and neck, but computed tomography (CT), magnetic resonance imaging (MRI), and scintigraphy of mandibular actinomycosis have not been fully described. Here, we report a case of mandibular actinomycosis with CT, MRI, and scintigraphy. The purpose of this article is to characterize the CT, MRI, and scintigraphy findings in cases of actinomycosis. Contrast-enhanced CT of the masticator space showed heterogeneous enhancement and a nonenhancing portion, suggestive of necrotic foci. Bone tissue algorithm CT showed an osteolytic lesion in the ramus of the left mandible only. On post-contrast T1-weighted images, the masticator space showed heterogeneous enhancement and nonenhancing portion, suggestive of necrotic foci. Bone scintigraphy revealed monostatic involvement of the mandible with a homogeneous intense uptake pattern. Gallium scintigraphy revealed significantly increased uptake in the left side of the face. These findings can be helpful for differentiating actinomycosis from other tumors of the mandible.