Figure 5. Time activity curves and bacterial heterogeneity.

(A and B) [¹¹C]-TMP PET/CT images of a 44-year-old woman with an acute exacerbation of cystic fibrosis (A) before and (B) after treatment with 2 weeks of i.v. ceftriaxone. Regions of interest were drawn around 2 separate pulmonary airspace opacities. In addition, reference regions were also drawn around a reference lymph node and paraspinal musculature and within the aorta. Comparing PET/CT images before and after treatment, the visible changes in relative [¹¹C]-TMP uptake in lesion 1 compared with lesion 2 demonstrate the bacterial heterogeneity and an apparent new infection with S. aureus based on sputum cultures. The patient received 487 MBq and 780 MBq of [¹¹C]-TMP at the first and second time points, respectively. PET images are scaled at 0–5 g/mL SUV and CT images are scaled at –1,024 to +300 HU.