High Spatial Inhomogeneity in the Intima-Media Thickness of the Common Carotid Artery is Associated with a Larger Degree of Stenosis in the Internal Carotid Artery: The PARISK Study

Purpose Inhomogeneity of arterial wall thickness may be indicative of distal plaques. This study investigates the intra-subject association between relative spatial intima-media thickness (IMT) inhomogeneity of the common carotid artery (CCA) and the degree of stenosis of plaques in the internal carotid artery (ICA). Materials and Methods We included 240 patients with a recent ischemic stroke or transient ischemic attack and mild-to-moderate stenosis in the ipsilateral ICA. IMT inhomogeneity was extracted from B-mode ultrasound recordings. The degree of ICA stenosis was assessed on CT angiography according to the European Carotid Surgery Trial method. Patients were divided into groups with a low (≤ 2 %) and a high (> 2 %) IMT inhomogeneity scaled with respect to the local end-diastolic diameter. Results 182 patients had suitable CT and ultrasound measurements. Relative CCA-IMT inhomogeneity was similar for the symptomatic and asymptomatic side (difference: 0.02 %, p = 0.85). High relative IMT inhomogeneity was associated with a larger IMT (difference: 235 µm, p < 0.001) and larger degree of ICA stenosis (difference: 5 %, p = 0.023) which remained significant (p = 0.016) after adjustment for common risk factors. Conclusion Regardless of common risk factors, high relative CCA-IMT inhomogeneity is associated with a greater degree of ICA stenosis and is therefore indicative of atherosclerotic disease. The predictive value of CCA-IMT inhomogeneity for plaque progression and recurrence of cerebrovascular symptoms will be determined in the follow-up phase of PARISK.