Abstract 19163: Non-Invasive Imaging Of Arterial Restenosis Using 3T Magnetic Resonance Imaging
Background: Restenosis of the carotid artery is a common problem following carotid endarterectomy, yet currently no consensus exists as to how it is best detected and treated. Magnetic Resonance Imaging (MRI) has not previously been used to provide detailed information on the composition of restenotic plaque in vivo.
Hypothesis: 3T MRI can be used to characterise the components of restenotic carotid plaque and to determine whether it differs from primary atherosclerotic plaque.
Methods: 50 patients were recruited; 25 had previously undergone carotid endarterectomy and 25 patients with primary atherosclerotic plaques served as controls. All patients underwent 3T MRI of the carotids using gadolinium-enhanced T1-, T2-, and proton density (PD)- weighted turbo spin echo imaging. Restenotic lesions were graded according to the MRI plaque components noted; chi-squared analysis and Fisher's exact test were used to compare the prevalence of plaque components between the restenosis and the control group.
Results: Three distinct types of restenosis were seen: five (20%; figure A, T1-weighted, * marks lumen, arrow marks restenosis) patients had recurrent carotid disease that demonstrated a predominance of fibrous tissue in the arterial wall, 12 (44%, figure B) had features suggestive of fibromuscular hyperplasia, and six patients (24%, figure C) had recurrent plaque characterised by lipid accumulation. Restenotic plaques were more likely to contain fibrous tissue (p=0.05) and smooth muscle cells (p<0.01), and less likely to contain lipid (p<0.01), than primary atherosclerotic plaques.
Conclusions: This is the first description of the use of MRI to investigate arterial restenosis. Restenotic lesions of the carotid artery fall into three distinct MRI types and may differ in composition from primary atherosclerotic plaques; these findings may thus explain the lower incidence of clinical events from recurrent carotid disease.
- © 2010 by American Heart Association, Inc.