[Iron-oxide-enhanced MR imaging of inflammatory atherosclerotic lesions: overview of experimental and initial clinical results].
Numerous pathologic studies in the 1990's have shown atherosclerosis to be a chronic inflammatory disorder. This new insight and the advent of new plaque-stabilizing drugs, in particular antilipemic agents (statins), have led to an increased clinical interest in the development of new imaging modalities. These are aimed at visualizing the inflammatory atherosclerotic wall lesion as reflecting the active progression of the disease process and at identifying so-called vulnerable or high-risk lesions that are associated with a higher rate of vascular complications. A diagnostic modality currently undergoing investigation in terms of its potential for the diagnostic assessment of atherosclerosis is contrast-enhanced magnetic resonance imaging (MRI) using certain blood pool contrast media such as ultrasmall superparamagnetic iron oxide (USPIO) particles. Endothelial dysfunction and macrophage infiltration are two crucial pathomechanisms of atherosclerosis and these mechanisms also underlie the accumulation of iron oxide particles in experimental and human atherosclerotic lesions. Experimental results furthermore suggest that there is selective uptake of iron oxide by thrombi. The following experimental MR imaging techniques have a potential for providing complementary diagnostic information in assessing atherosclerotic lesions: 1. Unenhanced MRI for visualizing vulnerable plaques (wall thickness, fibrous cap, lipid core). 2. Visualization of the vessel lumen and quantitative assessment of stenosis using iron-oxide-enhanced MR angiography. 3. Delayed MRI studies for the functional characterization of inflammatory lesions (T 2 -effects produced by iron oxide uptake in macrophages of inflammatory lesions) with a potential for identifying mural thrombus as a sign of plaque rupture (T 1 -effects produced by binding of iron oxide to the thrombus). This article presents the experimental and initial clinical results obtained with iron-oxide-enhanced MRI of atherosclerotic lesions.
Schmitz
S A
SA
Klinik und Poliklinik für Radiologie und Nuklearmedizin, Universitätsklinikum Benjamin Franklin, Berlin. s.schmitz@medizin.fu-berlin.de
D000818:Animals; D001158:Arteries / Q000473:pathology; D001161:Arteriosclerosis / Q000175:diagnosis*; D003287:Contrast Media; D003911:Dextrans; D004730:Endothelium, Vascular / Q000473:pathology; D052203:Ferrosoferric Oxide; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007501:Iron; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D010087:Oxides; D012680:Sensitivity and Specificity
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide