Fig. 1

PET, CT, and fused PET/CT images illustrate anatomical distribution of [¹⁸F]FPEB, a mGluR5 imaging ligand in an ALS mouse. Separate CT (left), PET (right bottom), and fused PET/CT (right above) images of an ALS mouse at stage 3. In the fused image, the sagittal slice (thickness 0.6 mm) shows enhanced accumulation of [¹⁸F]FPEB in brain, spinal cord, abdominal area, and bladder 60 min after administration of radioligand (120 μCi iv). Coronal, sagittal, and axial views of the brain in the PET study show high accumulation in cortical areas. Crosshair in the images illustrates the location of each slice. In these mice, we have observed progressively enhanced mGluR5 expression when the general health status declined. The CT image demonstrates the level of spatial detection that can be achieved with the present imaging technology. We can accurately detect and quantitate modulation of receptor binding and inflammatory response in small areas in spinal cord and brain