Arjen Lindenholz

149 Intracranial Atherosclerotic Burden and Cerebral Parenchymal Changes at 7T MRI 6 significance. That approach would leave no association between (enhancing) vessel wall lesions and cerebral parenchymal changes. Furthermore, several other cerebral parenchymal changes have been recognized to reflect (chronic) vascular damage due to SVD, such as cerebral microbleeds, which were not assessed in this study. 27 Ideally, the inclusion of a larger group of patients could improve the statistical reliability and enable inclusion of more potential confounders or effect modifiers, while assessment of these other cerebral parenchymal changes may contribute to a broader understanding of the potential associations between intracranial vessel wall lesion burden reflecting underlying large artery disease and the cerebral sequelae associated with SVD. Another limitation of assessing intracranial vessel wall lesion burden is the absence of a gold standard method to assess ICAS lesions found on MRI. However, this is a limitation of all studies on intracranial vessel wall MRI, and several post-mortem ex vivo imaging correlation studies have been performed, tentatively increasing the confidence that detected vessel wall lesions represent true intracranial atherosclerosis. 15,18,49 Yet, the cut-off point between confirmed early stage atherosclerotic lesions and non-pathological or natural variations of vessel wall thickness may be difficult to define. Conclusions Within this relatively small sample size, intracranial vessel wall lesion burden was associated with the presence of periventricular WMH and the presence of any type of infarct often linked to SVD, while no association was found with (large) cortical infarcts. The co-occurrence of intracranial vessel wall lesions and parenchymal manifestations generally attributed to SVD suggest that either vessel wall lesions of the large intracranial parent arteries eventually result in cerebral parenchymal manifestations of SVD, e.g., by occluding the orifices of smaller branching arteries, or that vascular changes occur in both large and small intracranial arteries simultaneously. In the future, studies with larger sample sizes are required to confirm these findings.