Haddad J, Latoche JD, Nigam S, et al. - This study was undertaken to explore the role of targeted imaging of very late antigen-4 (VLA-4), as a key integrin mediating the adhesion and recruitment of immune cells to inflamed tissues, in evaluating lung inflammation in a mouse model of lipopolysaccharide-induced acute lung injury (ALI). In C57BL/6J mice, ALI was induced by a single intratracheal administration of lipopolysaccharide (10, 20, or 40 μg per mouse). This study’s findings reveal the feasibility of molecular imaging of VLA-4, as a mechanistically relevant target in ALI, and the accuracy of VLA-4–targeted PET in the quantification of ongoing lung inflammation in a murine model.