Fig. 3
[18F]FDG PET/CT of a 69-year-old man on the 20th day of acute COVID-19, with respiratory failure, without neurological symptoms. Maximum intensity projection (MIP) (A) and axial PET/CT image fusion of the brain (B) show marked bilateral [18F]FDG uptake in lenticular nuclei. The axial plane of automatic delimitation of frontal and occipital lobes is shown in C and D. Quantitative data are displayed in a rainbow color scale as standard deviation (#StdDev) of the mean uptake of a normal database: in an axial plane in D, and as three-dimensional surface rendered displays of the left hemisphere of the brain in E (lateral view) and F (medial view). Reduced metabolism is seen in frontal lobes and temporo-occipital areas (respectively dark blue and light blue) in A and E. Also note the markedly increased brain metabolism in lenticular nuclei and thalami (red in D and F), suggesting a redistribution of brain metabolism from the neocortex to evolutionary ancient brain structures. During a 13-month follow up, no neurological symptoms or sequelae were detected. Quantification values (in #StdDev units) are: -4.6 / -2.6, for right / left frontal lobes; -3.3 / -2.4, for right / left temporal lobes; -3.0 / -3.9, for right / left occipital lobes; 11.5 / 12.5, for right / left lenticular nuclei; 3.7 / 4.8, for right / left thalami