Associations between Morphological Characteristics of Intracranial Arteries and Atherosclerosis Risk Factors in Subjects with Less Than 50% Intracranial Arterial Stenosis

ABSTRACT

PURPOSE: To assess associations between morphological characteristics of intracranial arteries in time-of-flight MR angiography (TOF-MRA) and atherosclerotic risk factors. MATERIALS AND METHODS: From January 2014 to October 2015, a total of 129 patients (65 men and 64 women) without intracranial arterial stenosis > 50% were included in this study. All MRIs were performed using a 3T machine with 3D TOF-MRA sequences. We evaluated irregularity, tortuosity, and dilatation of intracranial arteries in maximal intensity projection (MIP) of TOF-MRA. Subjects' risk factors for atherosclerosis including history of hypertension and diabetes were collected by reviewing their medical records. Associations between morphological characteristics and each known atherosclerosis risk factor were examined using univariate regression analysis. Multivariate regression models were built to determine combined association between those risk factors and morphologic changes of intracranial arteries. RESULTS: In multivariate analysis, hypertension (coefficient [95% CI] 0.162 [0.036, 0.289], P = 0.012) and absence of diabetes (coefficient [95% CI] −0.159 [−0.296, −0.023], P = 0.022) were associated with large diameter of intracranial arteries. Males (coefficient [95% CI] 0.11 [−0.006, 0.23], P = 0.062) and higher age (coefficient [95% CI] 0.003 [−0.001, 0.008], P = 0.138) had marginal association with increased diameter. Tortuosity was associated with old age (OR 1.04 [1.02, 1.07], P < 0.001). Irregular contour of intracranial arteries was significantly associated with old age (OR 1.05 [1.02, 1.09], P = 0.004), presence of diabetes (OR 2.88 [1.36, 6.15], P = 0.0058), and previous ischemic stroke (OR 3.91 [1.41, 11.16], P = 0.0092). CONCLUSION: Morphological characteristics (irregularity, tortuosity, dilatation) of intracranial arteries seen in TOF-MRA might be associated with atherosclerotic risk factors in subjects with no or mild stenosis.