Tc-99m-labeled small biomolecules as potential radiopharmaceuticals for infection and inflammation imaging

Accurate and rapid detection of infectious and inflammatory foci is of grea t importance for elucidation of the cause of the disease, early prevention of the onset of complications and rapid implementation of a tailored therap eutic regimen. Numerous imaging procedures have been developed for the visu alization of infectious and inflammatory lesions. Morphological and functio nal imaging modalities, including ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI), provide details of structural change s, variations in density and differences in proton content in tissues. Nucl ear medicine procedures using Tc-99m-labeled small biomolecules can be used for in vivo characterization of cellular structure and function and for mo nitoring biological changes in the infectious tissues at the molecular leve l. This article will focus on those receptor-based, target-specific Tc-99m radiopharmaceuticals under investigation in preclinical or clinical studies for infection and inflammation imaging. These include Tc-99m-labeled chemo tactic peptides, tuftsin receptor antagonists, LTB4 receptor antagonists, a ntimicrobial peptides and a fragment of human platelet factor 4.