Fig. 1

Serial brain magnetic resonance images (MRIs) and [¹⁸ F]-fluoro-2-deoxy-D-glucose positron emission tomographies (FDG-PETs). (A) Initial brain MRIs obtained 10 days after disappearance. Diffusion-weighted images (DWIs) show symmetric high signal intensities in the bilateral hippocampus and globus pallidus (upper row). Fluid-attenuated inversion recovery (FLAIR) images reveal prominent high signal intensities in the same lesions shown on DWIs (lower row). (B) Eight-month follow-up FLAIR images show diffuse cortical atrophy with confluent white matter hyperintensities. (C) FDG-PET mappings were obtained from the Australian e-Health Research Centre (https://aehrc.csiro.au/). The images were quantified and correlated with 3-D surface image using CapAIBL [20, 21] (https://milxcloud.csiro.au/). To quantify the uptake in PET images, focal uptake values are divided by those of the cerebellum (reference region). After quantification, a Z-score map is created on a 3-D surface image. Predominant precuneus hypometabolism in the initial map (upper row) progresses extensively to the bilateral frontoparietotemporal areas in the 8-month follow-up images (lower row)