Figure 4.

Performance of d-[¹¹C]ala in a murine model of acute bacterial infection. In all cases red arrows indicate the site of inoculation with live bacteria, while white arrows correspond to heat-killed bacteria. Representative images from μPET-CT studies using d-[¹¹C]ala, [¹⁸F]FDG, and [⁶⁸Ga]gallium citrate are juxtaposed with the corresponding ex vivo tissue analyses. As reflected by the images, the mean d-[¹¹C]ala accumulation for tissues infected with live bacteria was 3.5-fold higher than that seen for heat-killed inoculation. In contrast, this difference was not seen for [¹⁸F]FDG. For [⁶⁸Ga]gallium citrate a significant difference in tracer signal between inoculation sites was seen, but only 2-fold higher on the infected side.