PET Imaging of Osteomyelitis with [⁶⁸Ga]Ga-BP

A low-cost, easy-to-adopt noninvasive imaging modality for differentiating bacterial infection from inflammation is desirable to accurately diagnose bacterial infections. Herein, a bacteria-specific PET probe, [⁶⁸Ga]-Ga-BP, was developed and evaluated in rat models of foreign body-associated osteomyelitis induced by methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae and was directly compared with sterile inflammation and uninstrumented uninfected controls. [⁶⁸Ga]-Ga-BP-based imaging of MRSA-infected tibiae was also compared to [⁶⁸Ga]-Ga-citrate and [¹⁸F]-FDG. After iron depletion, dynamic PET/CT imaging was performed at 15-120 min postinjection of radiotracers, followed by assessment of ex vivo biodistribution. [⁶⁸Ga]-Ga-BP successfully detected tibial infection and demonstrated >6-fold higher uptake in infected tibiae with all three bacterial species versus contralateral tibiae via PET imaging. [⁶⁸Ga]-Ga-BP outperformed [⁶⁸Ga]-Ga-citrate and [¹⁸F]-FDG in identifying MRSA infection. [⁶⁸Ga]-Ga-BP represents a promising, noninvasive PET imaging agent for direct bacterial detection and bacterial infection treatment monitoring.