Abstract: Biomodulators, optionally linked to imaging-active moieties, can be administered to a host to enhance images thereof, e.g., NMR-, X-ray- or radio-images, preferably by increasing aberrant tissue signal intensity. Biomodulators can also condition tissue to enhance up-take of otherwise non-specific imaging agents. When linked to drugs, biomodulators can target the same to particular sites in the body.

Abstract: Biomodulators, optionally linked to imaging-active moieties, can be administered to a host to enhance images thereof, e.g., NMR-, X-ray- or radio-images, preferably by increasing aberrant tissue signal intensity. Biomodulators can also condition tissue to enhance uptake of otherwise non-specific imaging agents. When linked to drugs, biomodulators can target the same to particular sites in the body.

Abstract: Biomodulators, optionally linked to imaging-active moieties, can be administered to a host to enhance images thereof, e.g., NMR-, X-ray- or radio-images, preferably by increasing aberrant tissue signal intensity. Biomodulators can also condition tissue to enhance uptake of otherwise non-specific imaging agents. When linked to drugs, biomodulators can target the same to particular sites in the body.

Abstract: Biomodulators, optionally linked to imaging-active moieties, can be administered to a host to enhance images thereof, e.g., NMR-, X-ray- or radio-images, preferably by increasing aberrant tissue signal intensity. Biomodulators can also condition tissue to enhance uptake of otherwise non-specific imaging agents. When linked to drugs, biomodulators can target the same to particular sites in the body.

Abstract: Biomodulators, in conjunction with antibodies, tumor-specific agents or conjugates thereof, optionally linked to imaging-active moieties, can be administered to a host to enhance images thereof, e.g., NMR-, X-ray- or radioimages, preferably by increasing aberrant tissue signal intensity.

Abstract: Mixed anionic complexes of the type (MW.sub.m Y.sub.n Z.sub.p).sup.r- wherein M is a paramagnetic ion; W, Y, and Z are each different ligands which chelate M; and m+n+p.gtoreq.2 but preferably less than 5, with the proviso that at least two different ligands W, Y, Z are present in the complex; are provided as versatile NMR contrast and shift reagents, especially for clinical diagnostic imaging and spectroscopic procedures. In an exemplary embodiment, at least one of the ligands W, Y, Z is metabolizable by the target tissue, and at least one of the ligands W, Y, Z is substantially inert; the complex is thus tailorable to improve both physiological tolerance and tissue specificity of NMR contrast and shift reagents, while maintaining excellent contrast and shift effects for reliable and accurate results.