Arjen Lindenholz

141 Intracranial Atherosclerotic Burden and Cerebral Parenchymal Changes at 7T MRI 6 Distribution of intracranial vessel wall lesions and cerebral parenchymal changes Sixty-two patients (75%) had a total of 193 vessel wall lesions and 35 patients (43%) a total of 81 enhancing vessel wall lesions. The total number of (enhancing) vessel wall lesions per arterial segment is shown in Supplemental Table 1 . Sixty-eight patients (83%) had at least one cerebral parenchymal vascular lesion. Fifty-five patients (67%) had a total of 122 cortical infarcts. One patient (1%) had a small subcortical infarct of < 20mm, 23 patients (28%) had a total of 54 lacunes of presumed vascular origin, 15 patients (18%) had a total of 21 subcortical deep grey matter infarcts, and 16 patients (20%) had a total of 43 cortical microinfarcts. For the periventricular WMH 24 patients (29%) and for the deep WMH 25 patients (30%) had a Fazekas score of 2 or 3. All details regarding the detected cerebral parenchymal changes are shown in Supplemental Table 2. Intracranial vessel wall lesion burden and cerebral parenchymal changes Unadjusted and adjusted relative risks for the association between intracranial vessel wall lesion burden and the presence of cerebral parenchymal changes are shown as primary analyses in Table 2 . In our study population, vessel wall lesion burden was not associated with the presence of small cortical infarcts (adjusted relative risk 1.07, 95% CI, 0.98-1.17). Neither was an association found between vessel wall lesion burden and presence of lacunes of presumed vascular origin (adjusted relative risk 1.13, 95% CI, 0.95-1.34), deep grey matter infarcts (adjusted relative risk 1.25, 95% CI, 0.98-1.60 and cortical microinfarcts (adjusted relative risk 1.07, 95% CI, 0.85-1.36). When all subcortical infarcts were combined into one composite variable composing the infarcts often considered to be a manifestation of SVD, an association was found between vessel wall lesion burden and presence of an infarct (adjusted relative risk, 1.18; 95% CI, 1.03-1.35). In addition, the presence of moderately to severe (Fazekas 2-3) periventricular WMH was associated with vessel wall lesion burden (adjusted relative risk, 1.21; 95% CI, 1.02-1.42). No association was found between deep WMH and vessel wall lesion burden. An example of the presence of vessel wall lesions and a high WMH score is shown in Figure 2.