Abdominal magnetic resonance venography.

With the refinement of fast gradient-echo imaging, it is now possible to perform abdominal magnetic resonance venography completely noninvasively, without the use of oral or injected contrast agents. In this paper, we emphasize two-dimensional, time-of-flight angiographic techniques, as applied to the study of patency and flow in the veins of the abdomen. Magnetic resonance venography is routinely applicable to patients with portal disease, or suspected occlusion of the inferior vena cava, iliac veins or renal veins. Sequential, single-slice venographic images, acquired during breath holding, can be postprocessed to form projected venograms. Hemodyanmic information is derived using presaturation schemes, bolus-tracking or phase imaging. These techniques can also be used to establish the integrity of surgical portosystemic shunts.