A Rare Case of Odontogenic Lumbar Spondylodiscitis Demonstrated on 18F-FDG PET/CT

A 68-year-old man presented with 1 month of back pain after strenuous activity. No concomitant vertebral fracture was identified. Lumbar MRI revealed L2-3 endplate inflammation with vertebral bone marrow edema. ¹⁸F-FDG PET/CT demonstrated narrowing of the L2-3 intervertebral space with endplate and left facet bone destruction, paraspinal soft tissue thickening, and heterogeneous hypermetabolism. Spinal joint puncture biopsy confirmed inflammatory changes, and metagenomic next-generation sequencing of the biopsy specimen identified Streptococcus oralis as the causative pathogen. This case reports the FDG PET/CT findings of odontogenic lumbar spine infection.