Dilative arterial remodeling of the brain with different effects on the anterior and posterior circulation: an MRI study.

OBJECTIVE: The goal of the study was to investigate factors associated with dilation of the internal carotid artery (ICA) and basilar artery (BA), which reflect the anterior and posterior circulation respectively, and to examine if these arteries are affected differently by specific factors.

METHODS: The diameters of ICA and BA were measured using T2-weighted magnetic resonance (MR) images at the level of the brainstem in 304 outpatients, with the maximal width of the flow void taken as the diameter for each artery. The association between the diameters and clinical data including hemoglobin A1c (HbA1c) and estimated glomerular filtration rate (eGFR) was investigated. The same analysis was performed for the BA/ICA ratio.

RESULTS: Multiple regression analysis adjusted for confounding factors including gender and age showed that a lower eGFR was independently associated with dilation of both the ICA (beta coefficient -0.148, P=0.0135) and the BA (beta -0.219, P=0.0007). HbA1C was independently associated with a greater BA/ICA ratio (beta -0.183, P=0.0015) but eGFR did not show this association. Diabetes mellitus was significantly more frequent (P=0.0353) in patients with a BA/ICA ratio higher than the mean, compared to those with a lower BA/ICA ratio.

CONCLUSION: Kidney dysfunction was shown to be a dilative factor for the anterior and posterior circulation as reflected by the ICA and BA diameters, respectively. The association of the BA/ICA ratio with HbA1c suggests that diabetes mellitus may affect each circulation differently.