It should be considered that there can be variation in matching FDG uptake with histologic severity because more severe architectural distortion can lead to necrosis with more dead cells, therefore showing less uptake of radiotracer among metabolically inactive dead cells and nonviable tissue. Our study, however, shows that progressing inflammatory infiltrates on histology in the studied time period after acute influenza infection corresponds to radiologic trends. Additionally, our study demonstrates spatial progression with increased size and number of abnormal foci in the lung parenchyma during acute infection.