High resolution ex vivo magnetic resonance imaging of in situ coronary andaortic atherosclerotic plaque in a porcine model

Atherosclerotic plaque composition is central to the pathogenesis of plaque disruption and acute thrombosis. Thus, there is a need for accurate imagin g and characterization of atherosclerotic lesions. Even though there is no ideal animal model of atherosclerosis, the porcine model is considered to m ost closely resemble human atherosclerosis. We report the feasibility of MR imaging and characterizing of atherosclerotic lesions from in situ coronar y arteries and aortas in an ex vivo setting and validate this with histopat hology. Coronary and aortic atherosclerosis was induced in Yucatan mini-swi ne (n = 4) by a combination of atherogenic diet (6 months) and balloon inju ry. All coronary arteries were imaged ex vivo on the intact heart, preservi ng the curvature bf their course. The aorta also underwent MR imaging. The MR images were correlated with the matched histopathology sections for both the coronary arteries (n = 54) and the aortas (n = 43). MR imaging accurat ely characterized complex atherosclerotic lesions, including calcified, lip id rich, fibrocellular and hemorrhagic regions. Mean wall thickness for the coronary arteries (r = 0.94, slope: 0.81) and aortas (r = 0.94, slope: 0.8 1) as well as aortic plaque area (r = 0.97, slope: 0.90) was accurately det ermined by MR imaging (P < 0.0001). Coronary artery MR imaging is not limit ed by the curvature of the coronary arteries in the heart. MR imaging accur ately quantifies and characterizes coronary and aortic atherosclerotic lesi ons, including the vessel wall, in this experimental porcine model of compl ex atherosclerosis. This model may be useful for future study of MR imaging of atherosclerosis in vivo. (C) 2000 Elsevier Science Ireland Ltd. All rig hts reserved.