Remodeling of Carotid Arteries Detected with MR Imaging: Atherosclerosis Risk in Communities Carotid MRI Study

Abstract

Purpose:To determine the extent of thickening of the carotid arterial walls that may be accommodated by outward remodeling. Materials and Methods:Institutional review board approval was obtained at each participating site, and informed consent was obtained from each participant. All study sites conducted this study in compliance with HIPAA requirements. A total of 2066 participants (age range, 60-85 years) from the Atherosclerosis Risk in Communities (ARIC) study were enrolled in the ARIC Carotid MRI Study. Maximum wall thickness and luminal area were measured with gadolinium-enhanced magnetic resonance (MR) imaging in both common carotid arteries (CCAs) and in one internal carotid artery (ICA) 2 mm above the fl ow divider. Complete data were available for 1064 ICAs and 3348 CCAs. The association of maximum wall thickness with lumen area was evaluated with linear regression, and adjustments were made for participant age, sex, race, height, and height squared . Results:In the ICA, lumen area was relatively constant across patients with a wall thickness of 1.38 mm or less . In patients with a wall thickness of more than 1.38 mm, however, lumen area decreased linearly as wall thickness increased. Wall area represented a median of 61.9% of the area circumscribed by the vessel at a maximum wall thickness of 1.50 mm 6 0.05 (standard deviation) and 75.4% at a maximum wall thickness of 4.0 mm 6 0.10. In the CCA, lumen area was preserved across wall thicknesses less than 2.06 mm, representing 99% of vessels. Conclusion:Atherosclerotic thickening in the ICA appears to be accommodated for vessels with a maximum wall thickness of less than 1.5 mm. Beyond this threshold, greater thickness is associated with a smaller lumen. The CCA appears to accommodate a wall thickness of less than 2.0 mm. These estimates indicate that the carotid arteries are able to compensate for a greater degree of thickening than are the coronary arteries.q RSNA, 2010

Carotid Bifurcation Geometry Is an Independent Predictor of Early Wall Thickening at the Carotid Bulb

“…In some cases, the carotid plaque of interest was located far above the flow divider, and so the FD+1 location was not included in the black blood series. As a result, ICA wall thickness data at FD+1 were available only for N=1064 ICAs, 16 which is the cohort from which our study groups were defined by applying increasingly stringent exclusion criteria to progressively filter out those cases that were likely to include an effect of wall thickening on lumen geometry.…”

Evaluation of carotid artery outward remodeling by T1-weighted magnetic resonance imaging in carotid endarterectomy and stenting

“…In our previous study, to evaluate the effect of this natural variance, we analyzed 20 lesions (20 patients having lacunar infarction without any carotid artery stenosis; 18 men; mean age, 66. 8 the maximum stenosis of the internal carotid artery than the control group. However, the external CSVA at the distal internal carotid artery was almost identical in these groups.…”

“…In coronary arteries, this process plays an important role in plaque vulnerability. [2][3][4][5][6] Outward remodeling of the carotid artery has also been documented, 7,8 as has a high rate of stroke recurrence with low-grade (<50%) stenosis 9 and the association of symptoms with high-grade ($50%) stenosis. 10,11 Carotid plaque imaging using a T1-weighted magnetic resonance imaging (T1-MRI) technique, such as magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) or cardiac-gated black-blood MRI, is widely used to predict vulnerability.…”

Comparison of carotid arterial morphology and plaque composition between patients with acute coronary syndrome and stable coronary artery disease: a high-resolution magnetic resonance imaging study

“…We performed a comprehensive comparison in the characteristics of carotid arterial morphology between ACS and SCAD patients in Max-TVA, mean TVA, Min-LA, mean LA, Max-WA, mean WA, Max-WT, mean WT, Max-NWI, mean NWI, and Max-stenosis. TVA, LA, and WA reflect the severity of carotid atherosclerosis in outward remodeling, lumen reduction, and plaque burden [20]. Luminal Max-stenosis remains the main indictor for assessing the clinical risk from carotid atherosclerotic disease [21].…”