Contrast-enhanced MR angiography of the mesenteric circulation: a pictorial essay.

Outstanding results have been achieved with magnetic resonance (MR) angiography, which has become competitive with conventional angiography as a vascular imaging technique. With the advances in gradient technology and the capability of imaging vessels in a single breath hold, one can track an intravenous bolus of paramagnetic contrast agent and evaluate the entire mesenteric circulation. Use of a breath-hold technique obviates the problem of motion artifact. Use of targeted maximum-intensity projection images from the three-dimensional (3D) volume data allows evaluation of the vascular anatomy at different phases (arterial and venous) of contrast enhancement. MR angiography performed with a contrast-enhanced breath-hold fat-suppressed 3D technique allows visualization of the superior mesenteric vessels, celiac artery, and portal vein in healthy subjects. Pathologic conditions of the mesenteric vessels that can be identified with this technique include stenosis or occlusion of the superior mesenteric artery, celiac artery aneurysm, thrombosis of the superior mesenteric vein, portal hypertension with varices, and vascular invasion by pancreatic carcinoma.