Multimodal Neuroimaging of Mouse Brain

PET and CT data of each animal was acquired within 24 h of the MR scans. The mice were anesthetized with 2 % isoflurane and positioned in a microPET Focus 220 (Siemens, Knoxville, TN). Dynamic PET data was acquired for 60 min following a retro-orbital administration of ~ 18 MBq/0.2 ml [¹⁸F]VUIIS1008. The dynamic data were binned into the following variable length frames: twelve 5-s frames, four 60-s frames, one 5-min frame, and five 10-min frames. The MAP algorithm was used to reconstruct the data into 128 × 128 × 95 slices with a voxel size of 0.095 × 0.095 × 0.08 cm³ at a beta value of 0.01. CT scans were next acquired to facilitate anatomic co-registration of the PET and MRI data. Mice were imaged in an Inveon CT (Siemens preclinical, Knoxville TN) following an IP injection of ~ 0.2 ml of the contrast agent Optiray (Mallinckrodt Inc., St. Louis, MO), which enables visualization of the bladder. Note that TSPO ligands are not cleared via the kidneys [13 (link)]. The CT data was collected using the following parameters: beam intensity = 180 mAs, tube voltage = 80 kVp, reconstructed image matrix = 512 × 512 × 512, and voxel size = 0.1 × 0.1 × 0.1 mm³.