Arjen Lindenholz

110 CHAPTER 5 Abstract Background: Intracranial atherosclerosis is an important cause of ischemic stroke and is associated with several vascular risk factors. Current imaging is mainly based on the assessment of luminal narrowing rather than abnormalities in the vessel wall. Purpose: To investigate the relation between vascular risk factors and atherosclerotic lesion burden of intracranial arteries assessed with vessel wall MRI at 7T in participants with ischemic stroke or transient ischemic attack (TIA). Materials and Methods: In this prospective study (Trial ID NTR2119, www.trialregister.nl ), study participants who presented with ischemic stroke or TIA of the anterior circulation between December 2009 and September 2017 underwent pre- and postcontrast 7T vessel wall MRI within three months onset. All large arteries of the intracranial circulation were assessed for number, location, and enhancement of vessel wall lesions. Generalized Estimating Equations for Poisson regression were used to investigate the relationship between vascular risk factors and number or enhancement of vessel wall lesions. Results: Ninety participants (52 men; mean age, 60 years) were evaluated. Increasing age (relative risk (RR), 1.02; 95% confidence interval (CI), 1.01-1.03), hypertension (RR, 1.46; 95% CI, 1.06-2.02), diabetes mellitus (RR, 1.67; 95% CI, 1.20- 2.33), and a higher multivariable vascular risk score (the Second Manifestations of ARTerial disease (SMART) risk score, RR, 1.01; 95% CI, 1.00-1.02) were associated with a higher number of vessel wall lesions in the anterior circulation. Contrast- enhancing vessel wall lesions were only associated with increasing age (RR, 1.03; 95% CI, 1.01-1.05). No association was found between smoking and the number of vessel wall lesions. Conclusions: Except for smoking, traditional common cardiovascular risk factors were associated with a higher number and enhancement of intracranial vessel wall lesions at 7T MRI in individuals evaluated after ischemic stroke or transient ischemic attack.