FIG 7.

Distribution of cellular uptake of radiolabeled FDG during influenza virus infection in ferrets. Female ferrets were infected with 10⁶ TCID₅₀s of the H1N1pdm virus (A/KY/180/2010). A radiolabeled glucose analog (FDG) was injected at 0.25, 1, and 3 days postinfection, and ferrets (2 per time point) were imaged 1 h later. Ferrets were euthanized immediately after imaging, and lung tissues were prepared for histology. (A) The temporal distribution of FDG uptake (maximum standard uptake value [SUVmax] within a defined volume) was measured in images taken by positron emission tomography after locating histology slices by using anatomical references in registered computed tomography images. These areas matched areas analyzed for neutrophil infiltration and approximate a 3D grid of each ferret caudal lung lobe. (B) Spatial distribution of FDG uptake at sites in the ferret lung grouped by distance from IAV nucleoprotein (NP)-positive cells within the lungs. The presence of the H1N1pdm virus was measured by immunohistochemical staining for viral nucleoprotein. Asterisks indicate statistically significant differences from mock-infected animals.