Abstract: An improved method for lymphoscintigraphy or magnetic resonance lymphography involves subtraction of a negative image produced using a gross imaging agent from a positive image produced with a specific antibody imaging agent. Another embodiment of the invention uses an antibody to lymphatic tissue as an imaging agent for lymphatics. A further embodiment uses a magnetic resonance image enhancing agent for magnetic resonance lymphography. Yet another embodiment uses labeled antibodies against organ antigens for scintigraphic and magnetic resonance organ imaging.Reagents and kits for use in the foregoing method are also provided.

Abstract: .sup.99 m Tc-labeling of antibodies and antibody fragments, either unconjugated or conjugated to DTPA, is effected in the presence of molar excess of free or carrier-bound DTPA to substantially completely inhibit direct technetium binding to non-stable binding sites on the antibody. The resultant .sup.99m Tc-labeled antibody has a stable label and is useful for, inter alia, tumor imaging by gamma scintigraphy and/or tumor therapy. Rhenium-labeling can be similarly effected.