Paramagnetic pharmaceuticals for magnetic resonance imaging. 
Complexes of paramagnetic ions that are tissue-, organ- or tumor-specific will supplement routine magnetic resonance imaging, help assess organ perfusion, and in some cases assess specific organ function.  Studies are described in animals and man and the results suggest that dilute iron solutions may be useful for contrast-enhancement of the gastrointestinal tract; that ferrioxamine B, a stable ferric iron complex, appears to permit identification of focal blood-brain-barrier defects and to assess renal excretory function; and that gadolinium-DTPA can produce contrast-enhancement of a variety of lesions.  In addition, gadolinium-DTPA can detect a breakdown in the blood-brain-barrier and can delineate functioning myocardium in the setting of acute ischemia.