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Arterial walls stiffen with age, cardiovascular risk factors, and various vascular diseases, which may lead to less damping of the arterial blood flow pulse, subsequent microvascular damage, and enlarged perivascular spaces (PVS). However, the exact interplay between these processes is unclear. This study aimed to investigate the relation between blood flow velocity pulsatility in the small lenticulostriate arteries and their supplying middle cerebral artery and the respective damping factor (DF), with the number of MRI-visible PVS in elderly subjects. Blood flow velocity waveforms were obtained in 45 subjects (median age [range]: 64 [48–81] years, 47% male) using 7T MRI. PVS were scored in the basal ganglia (BG) and centrum semiovale (CSO). Spearman correlation analyses were used to determine associations of the blood flow pulsatility and the DF, with PVS score, adjusted for age and sex. We found a significant association between a lower DF and a higher number of PVS in the BG (rs = −0.352, P = 0.021), but not in the CSO. This finding supports the supposed pathophysiological mechanism in which excessive kinetic energy deposition leads to damage of small perforating arteries and contributes to the enlargement of PVS at the level of the BG, but possible other pathways might also be of influence. [ABSTRACT FROM AUTHOR]

4D phase contrast magnetic resonance imaging (PC-MRI) allows for the visualization and quantification of the cerebral blood flow. A drawback of software that is used to quantify the cerebral blood flow is that it oftentimes assumes a static arterial luminal area over the cardiac cycle. Quantifying the lumen area pulsatility index (aPI), i.e. the change in lumen area due to an increase in distending pressure over the cardiac cycle, can provide insight in the stiffness of the arteries. Arterial stiffness has received increased attention as a predictor in the development of cerebrovascular disease. In this study, we introduce software that allows for measurement of the aPI as well as the blood flow velocity pulsatility index (vPI) from 4D PC-MRI. The internal carotid arteries of seven volunteers were imaged using 7 T MRI. The aPI and vPI measurements from 4D PC-MRI were validated against measurements from 2D PC-MRI at two levels of the internal carotid arteries (C3 and C7). The aPI and vPI computed from 4D PC-MRI were comparable to those measured from 2D PC-MRI (aPI: mean difference: 0.03 (limits of agreement: −0.14 – 0.23); vPI: 0.03 (−0.17–0.23)). The measured blood flow rate for the C3 and C7 segments was similar, indicating that our proposed software correctly captures the variation in arterial lumen area and blood flow velocity that exists along the distal end of the carotid artery. Our software may potentially aid in identifying changes in arterial stiffness of the intracranial arteries caused by pathological changes to the vessel wall. [ABSTRACT FROM AUTHOR]