The present application discloses compositions and methods of synthesis and use of 18F or 19F-labeled molecules of use in PET, SPECT and/or MR imaging. Preferably, the 18F or 19F is conjugated to a targeting molecule by formation of a complex with a group IIIA metal and binding of the complex to a bifunctional chelating agent, which may be directly or indirectly attached to the targeting molecule. In other embodiments, the 18F or 19F labeled moiety may comprise a targetable construct used in combination with a bispecific antibody to target a disease-associated antigen. The disclosed methods and compositions allow the simple and reproducible labeling of molecules at very high efficiency and specific activity in 30 minutes or less. In preferred embodiments, the labeled molecule may be used for imaging in a subject without purification after labeling.