18 F-DPA-714 PET/MRI reveals early and widespread neuroinflammation in sporadic Creutzfeldt–Jakob disease: a case report

Background Creutzfeldt–Jakob disease (CJD) is a fatal neurodegenerative disorder caused by prion proteins, with microglial activation being a key immunopathological feature. This case report demonstrates the application of 18 F-DPA-714 positron emission tomography (PET)/MRI, a second-generation translocator protein ligand, to visualise microglial activation in vivo in a patient with sporadic CJD (sCJD). Case presentation A 57-year-old woman presented with progressive rapid cognitive decline and behavioural change. MRI revealed restricted diffusion within the patchy cortical ribbon of bilateral frontal, parietal, occipital lobes and right caput nuclei caudate. Lumbar puncture revealed positive 14-3-3 protein and robustly positive real-time quaking-induced conversion assay, fulfilling the diagnostic criteria for definite sCJD. 18 F-DPA-714 PET/MRI showed extensive tracer uptake in bilateral cortical regions, caudate nuclei and the thalamus, indicating widespread microglial activation. The extent of abnormality on PET exceeded that seen on initial MRI, suggesting higher sensitivity for early pathological changes. Conclusions This is the first reported case of sCJD evaluated with 18 F-DPA-714 PET/MRI. The findings suggest that 18 F-DPA-714 PET/MRI may provide complementary sensitivity beyond structural MRI, potentially improving early diagnostic confidence in sCJD.