Labeled chemotactic peptides to image focal sites of infection or inflammation

The invention relates to a method of detecting a site of infection or inflammation, and a method for treating such infection or inflammation, in an individual by administering to the individual a diagnostically or therapeutically effective amount of detectably labeled, therapeutic, or therapeutically-conjugated, chemotactic peptide that accumulates substantially at the infected or inflamed site, said chemotactic peptide having the general structure X-Y-Leu-Phe-[Z]n-W, wherein: X is an amino protecting group, Y is an amino acid residue, Z is a spacer sequence, n is 0 or 1, and W is a labeling or attachment substituent.