FIGURE 2.  MRI and ¹⁸F-FDG PET scans of 4 subjects. (A) Control subject, male, age = 40 y, MMSE = 30, CDR = 0. (B) FAD, female, age = 35 y, MMSE = 30, CDR = 0 (Table 1, FAD-1). Bilateral hypometabolism of parietal cortex and MTL is evident on PET in absence of atrophy on MRI. Hypometabolism is more severe in left hemisphere. (C) FAD, male, age = 41 y, MMSE = 30, CDR = 0.5 (Table 1, FAD-3). Bilateral hypometabolism of parietal and temporal cortices and of MTL is evident on PET in absence of atrophy on MRI. MTL hypometabolism is more severe in left hemisphere. (D) FAD, female, age = 47 y, MMSE = 25, CDR = 0 (Table 1, FAD-6). Hypometabolism of parietal regions and MTL (bilaterally) and of left temporal lobe is evident on PET. Mild atrophy is present on MRI in parietal/precuneus regions. Within these regions, atrophy correction increased the MRglc measures by 10%, which were still 1 SD below control subjects' mean. Coregistered PET and MRI scans are shown at high (top row), middle (middle row), and low (bottom row) transaxial levels. PET scans are displayed in a blue-to-red color-coded scale, with intensity in each pixel representing radioactive counts per second. ¹⁸F-FDG PET images are shown using the same color scale. Areas of regional hypometabolism on PET are indicated by arrows on first slice showing abnormalities.