Noncoronary and coronary atherothrombotic plaque imaging and monitoring of therapy by MRI

Numerous imaging modalities including thermography, near infra-red spectroscopy, Raman spectroscopy, optical coherence tomography, ultrafast CT, MRI, and ultrasound have been applied to the characterization of atherothrombotic plaques and are reviewed in detail elsewhere in this issue; however, MRI has the greatest potential for clinical application. It is suited to this role because it is noninvasive, does not involve ionizing radiation, can be repeated serially, and provides high-resolution images of both vessel wall and lumen. Atherothrombosis usually develops silently over many years, although significant lesions are commonly present as early as the second decade [1]. Lipid-lowering drugs have demonstrated efficacy and safety in the primary prevention of the complications of atherothrombosis [2,3], but current guidelines do not include the presence of subclinical atherosclerosis in decisions about therapy [4]. In the future, risk stratification, which includes noninvasive identification and characterization of atherothrombosis, may direct, the type and intensity of, treatment in individual patients, even before clinical disease has been allowed to manifest. Our expanding knowledge of plaque composition, biology, and behavior demands that imaging modalities provide both quantitative and qualitative information about the plaque.