Imaging Characteristics of Brain SPECT, PET, and MRI in Neurosyphilis.

The incidence of neurosyphilis has declined since effective penicillin therapy against Treponema pallidum was introduced. However, the diagnosis of neurosyphilis early in the disease course is very important in order to select appropriate antibiotic therapy. We report brain MRI, SPECT with Tc-99m ECD, and PET with F-18 FDG findings before antibiotic therapy in a neurosyphilis patient with neurological symptoms. The cerebral cortices showed hypoperfusion with a patchy distribution on SPECT and foci with high signal intensity on MRI, suggesting ischemia. Brain PET showed areas with hypometabolism in the temporoparietal lobes bilaterally. © Korean Society of Nuclear Medicine 2021.