Association between White Matter Ischaemia and Carotid Plaque Morphology as Defined by High-resolution In Vivo MRI

Objectives and designBoth carotid plaque morphology and severity of white matter ischaemia (WMI) have been shown to be independent predictors of stroke risk. This study tests the hypothesis that there is an association between carotid plaque morphology as determined by high-resolution carotid MRI and WMI.Materials and methodsForty patients (80 arteries) with at least 40% stenosis on screening Doppler ultrasound were recruited and underwent high-resolution axial carotid MRI at 1.5 T. In a blinded manner, plaque characteristics such as lipid core, fibrous cap, intraplaque haemorrhage, lumen area, plaque area, and American Heart Association (AHA) classification were qualitatively and quantitatively evaluated. The severity of WMI was independently quantified using a modified Scheltens score based on standard brain Fluid-Attenuated Inversion Recovery. Linear mixed effect models were used to test if carotid plaque characteristics could independently predict severity of WMI.ResultsHypertension (p = 0.005) and previous a history of transient ischaemic attack or stroke (p = 0.038) were found to be significant predictors of severity of WMI. After accounting for confounding variables, no significant association was found between the modified Scheltens score and lipid core size (p = 0.122), fibrous cap status (p = 0.991), intraplaque haemorrhage (p = 0.708), plaque area (0.835), lumen area (0.371) or an AHA Type VI complex plaque (p = 0.195).ConclusionsCarotid plaque morphology as defined by MRI does not independently predict severity of WMI.