The association between expansive arterial remodeling detected by high-resolution MRI in carotid artery stenosis and clinical presentation

Abstract

OBJECT The purpose of the present study was to investigate the association between carotid artery (CA) expansive remodeling (ER) and symptoms of cerebral ischemia. METHODS One hundred twenty-two consecutive CAs scheduled for CA endarterectomy (CEA) or CA stent placement (CAS) were retrospectively studied. After excluding 22 CAs (2 were contraindicated for MRI, 8 had near-occlusion, 6 had poor image quality, and 6 had restenosis after CEA or CAS), there were 100 CAs (100 patients) included in the final analysis. The study included 50 symptomatic patients (mean age 73.6 ± 8.9 years, 6 women, mean stenosis 68.5% ± 21.3%) and 50 asymptomatic patients (mean age 72.0 ± 5.9 years, 5 women, mean stenosis 79.4% ± 8.85%). Expansive remodeling was defined as enlargement of the internal carotid artery (ICA) with outward plaque growth. The ER ratio was calculated by dividing the maximum distance between the lumen and the outer borders of the plaque perpendicular to the axis of the ICA by the maximal luminal diameter of the distal ICA at a region unaffected by atherosclerosis using long-axis, high-resolution MRI. RESULTS The ER ratio of the atherosclerotic CA was significantly greater than that of normal physiological expansion (carotid bulb; p < 0.01). The ER ratio of symptomatic CA stenosis (median 1.94, interquartile range [IQR] 1.58–2.23) was significantly greater than that of asymptomatic CA stenosis (median 1.52, IQR 1.34–1.81; p = 0.0001). When the cutoff value of the ER ratio was set to 1.88, the sensitivity and specificity to detect symptoms were 0.6 and 0.78, respectively. The ER ratio of symptomatic patients was consistently high regardless of the degree of stenosis. CONCLUSIONS There was a significant correlation between ER ratio and ischemic symptoms. The ER ratio might be a potential indicator of vulnerable plaque, which requires further validation by prospective observational study of asymptomatic patients.

Carotid plaque with expansive arterial remodeling is a risk factor for ischemic complication following carotid artery stenting

“…ERR was calculated from the long-axis MRI T1-weighted plaque image according to the method described by Yoshida et al [10]. ERR was defined as the ratio of the maximum distance between the inner border of the arterial lumen and outer borders of the plaque to the maximal outside diameter of the internal carotid artery distal to the plaque ( Fig.…”

“…A promising approach would be to establish a logical stratification scheme to improve risk assessment for ischemic complications. Recent studies suggest that expansive arterial remodeling is related to plaque vulnerability [9,10]. Based on these findings, we tested the hypothesis that expansive arterial remodeling is a predictor of ischemic complications following CAS.…”

Carotid artery plaque assessment using quantitative expansive remodeling evaluation and MRI plaque signal intensity

“…A high value was defined as 2 standard deviations (1.66) or more of the mean control ERR (1.36), which was calculated from normal carotid arteries without stenosis in our previous study. 34 In the same previous study, the mean ERR of patients with carotid stenosis was 1.68 ± 0.40, and the receiver-operating characteristic analysis found that when the cutoff value of ERR was set at 1.88, the sensitivity and specificity for the detection of ischemic symptom were 0.6 and 0.78, respectively. If the cutoff value of ERR was set at 1.88 in the present study, the number of patients with ischemic events within 6 months was also significantly higher in Group A (rSI ≥ 1.4 and ERR ≥ 1.88) than in Group D (rSI < 1.4 and ERR < 1.88; p = 0.01).…”

“…18 The ERR was calculated using long-axis BB-MRI and the following formula ( In our previous study about the ERR, the control ERR measured in the contralateral nonatherosclerotic ICA in patients with unilateral carotid artery stenosis was reported. 34 The control ERR (mean ± SD) was 1.36 ± 0.15. Two SDs of the mean control ERR, 1.66 or more, was defined as high ERR.…”

“…34 The measurement technique for the ERR was developed by applying the method used in NASCET to evaluate stenosis. 18 The ERR was calculated using long-axis BB-MRI and the following formula ( In our previous study about the ERR, the control ERR measured in the contralateral nonatherosclerotic ICA in patients with unilateral carotid artery stenosis was reported.…”