Head-to-Head Comparison of 68 Ga-Citrate and 18 F-FDG PET/CT for Detection of Infectious Foci in Patients with Staphylococcus aureus Bacteraemia

This study evaluated the potential of Ga-citrate positron emission tomography/computed tomography (PET/CT) for the detection of infectious foci in patients with bacteraemia by comparing it with 2-[ F]fluoro-2-deoxy- -glucose ( F-FDG) PET/CT. Four patients admitted to hospital due to bacteraemia underwent both F-FDG and Ga-citrate whole-body PET/CT scans to detect infectious foci. The time from hospital admission and the initiation of antibiotic treatment to the first PET/CT was 4-10 days. The time interval between F-FDG and Ga-citrate PET/CT was 1-4 days. Three patients had vertebral osteomyelitis (spondylodiscitis) and one had osteomyelitis in the toe; these were detected by both F-FDG (maximum standardised uptake value [SUV ] 6.0 ± 1.0) and Ga-citrate (SUV 6.8 ± 3.5, = 0.61). Three patients had soft tissue infectious foci, with more intense F-FDG uptake (SUV 6.5 ± 2.5) than Ga-citrate uptake (SUV 3.9 ± 1.2, = 0.0033). Our small cohort of patients with bacteraemia revealed that Ga-citrate PET/CT is comparable to F-FDG PET/CT for detection of osteomyelitis, whereas F-FDG resulted in a higher signal for the detection of soft tissue infectious foci.