PET/CT Imaging of Candida Infection in Mice

Three mice from each group were anaesthetized by intraperitoneal injection of 1% pentobarbital and tails were intravenously injected with [¹⁸F]FDG (Guangzhou HTA Isotope Medical Co. Ltd) (10–11 MBq) at 24, 48 and 72 h after infection with C. albicans (5 × 10⁵ CFU). Forty minutes after the injection, the mice were scanned with a small-animal PET/CT scanner (Inveon) for 20 min. All PET images were reconstructed with the maximum a posteriori (MAP) reconstruction algorithm in Inveon Acquisition Workspace (Siemens Medical Solutions Inc.) and analysed with Inveon Research Workspace 4.2 (Siemens Medical Solutions Inc.) after the coregistration of the PET/CT images. Regions of interest (ROIs) were drawn in the kidneys. The radioactivity density from image analysis is presented as the percent injected dose per gram (% ID/g). After the final imaging time point, the mice were sacrificed. The blood, brain, heart, lungs, liver, spleen, kidneys, stomach, colon and muscle were harvested for ex vivo biodistribution analysis. The radioactivity in each organ was measured with an automatic gamma counter (Perkin-Elmer) after which the organ weights were determined with a balance. The biodistribution is presented as a percent of the injected dose per gram (% ID/g)^{45 (link),46 (link)}.