The gadolinium based blood pool contrast agent gadofosveset trisodium allows first pass contrast enhanced magnetic resonance angiography (CE-MRA) similar to usual extracellular agents.  However, this is achieved at lower dose due to the increased specific relaxivity engendered as a result of protein binding.  This protein binding is also the basis for the prolonged intravascular half life of approximately 28 minutes allowing imaging up to 60 minutes. This allows high spatial resolution images to be acquired since the contrast is in a 'steady state' unlike first-pass imaging, hence there is essentially no time constraint for the image acquisition sequence.  This longer time for acquisition allows potentially very high spatial resolution and the resultant images show arteries and veins to be equally enhanced, readily allowing assessment of venous anatomy and pathology.  This is useful not only in primary venous pathologies but also in the adjunctive assessment of patients with primarily arterial disease were venous imaging can help treatment planning.