Neuroimaging clinics of North America
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Neuroimaging Clin. N. Am. · Aug 2002
ReviewDiffusion and perfusion MRI for the assessment of carotid atherosclerosis.
Atherosclerotic disease of the extracranial vessels is a frequent cause of cerebral ischemia and stroke. Many natural history studies and prospective treatment trials with large patient samples have focused on optimal patient assessment in regard to medical or interventional measures. ⋯ Besides MRA improvements, DWI and PWI are increasingly used in addition to conventional MR contrasts (PD, T2-, T1-weighted MRI) in attempts to gather information on tissue status and the pathophysiology of hemodynamic compromise and cerebral ischemia in patients with carotid artery stenosis. Obtaining background information using this array of MR data may eventually become a basis for optimal risk-benefit assessment in patients with carotid artery stenosis.
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Neuroimaging Clin. N. Am. · Aug 2002
ReviewNoninvasive imaging of atherosclerotic plaque in the arch of the aorta with transcutaneous B-mode ultrasonography.
Atherosclerotic plaque at the arch of the aorta has been identified as a potential source for atheroembolic stroke. Imaging of aortic arch plaque can be performed with transesophageal echocardiography (TEE), but TEE is an invasive procedure. ⋯ Noninvasive imaging of the aortic arch can be employed in diagnosing the etiology of cerebrovascular disease in patients with stroke or transient ischemic attack in conjunction with duplex B-mode sonography of the extracranial carotid arteries. It also provides a noninvasive method for studying atherosclerotic plaque in the aortic arch which is applicable for investigational studies of the mechanisms of atherosclerosis and evaluation of pharmacological agents designed to treat atherosclerotic disease.
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Neuroimaging Clin. N. Am. · Aug 2002
ReviewB-mode ultrasound and spiral CT for the assessment of carotid atherosclerosis.
More studies on the natural history of carotid artery plaques are needed to predict more reliably which plaque types or features are the most dangerous (see Table 2). Studies on carotid and coronary endarterectomy specimens indicate a dynamic process of rupture, thrombus formation, healing, and remodeling of the plaque. A plaque from a symptomatic patient may not show any signs of plaque rupture if the plaque has healed or evolved since the debut of symptoms. ⋯ This progress is most necessary, considering the very high demands for surrogate endpoints and risk markers in clinical intervention studies. Whether ultrasonic plaque characterization can be implemented in broad general clinical practice, for example, in screening of individuals at high risk of developing atherosclerosis and ischemic events, has to be based upon data from large prospective studies with long-term follow-up. IMT is already used in population screening, as in the ARIC study [9,101].
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The assessment of atherothrombotic plaques by imaging techniques is essential for the in vivo identification of vulnerable plaques. Several invasive and noninvasive imaging techniques are available to assess atherothrombotic disease. The use of some of the available imaging modalities for the study of regression and progression of atherothrombosis are described in more detail in the subsequent articles.
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Neuroimaging Clin. N. Am. · Aug 2002
ReviewNoncoronary and coronary atherothrombotic plaque imaging and monitoring of therapy by MRI.
In the future, the use of imaging methods to quantify the progression and regression of atherosclerosis could play a strong role in the management of patients. High-resolution, noninvasive MRI may provide exhaustive 3-D anatomic information about the lumen and the vessel wall. ⋯ The high resolution of MRI and the development of sophisticated contrast agents offer the promise of molecular in vivo molecular imaging of the plaque. This may aid early intervention (e.g., lipid lowering drug regiments) in both primary and secondary treatment of vascular disease in all arterial beds.