Perivascular spaces on 7 Tesla brain MRI are related to markers of small vessel disease but not to age or cardiovascular risk factors

Abstract

Cerebral perivascular spaces (PVS) are small physiological structures around blood vessels in the brain. MRI visible PVS are associated with ageing and cerebral small vessel disease (SVD). 7 Tesla (7T) MRI improves PVS detection. We investigated the association of age, vascular risk factors, and imaging markers of SVD with PVS counts on 7 T MRI, in 50 persons aged ≥ 40. The average PVS count ± SD in the right hemisphere was 17 ± 6 in the basal ganglia and 71 ± 28 in the semioval centre. We observed no relation between age or vascular risk factors and PVS counts. The presence of microbleeds was related to more PVS in the basal ganglia (standardized beta 0.32; p = 0.04) and semioval centre (standardized beta 0.39; p = 0.01), and white matter hyperintensity volume to more PVS in the basal ganglia (standardized beta 0.41; p = 0.02). We conclude that PVS counts on 7T MRI are high and are related SVD markers, but not to age and vascular risk factors. This latter finding may indicate that due to the high sensitivity of 7T MRI, the correlation of PVS counts with age or vascular risk factors may be attenuated by the detection of "normal", non-pathological PVS.

Keywords: Cerebrovascular disease; MRI; aging; brain imaging; microcirculation; physiology.

Figure 1.

Flowchart showing the in- and exclusion of subjects from the UDES2 and PREDICT-MR study.

Figure 2.

Selection of the slices on which PVS were counted and example of PVS counting. (a) 35 mm sagittal maximum intensity projection (maxIP) showing the slices on two slices on which PVS were counted in the BG and CSO. (b) The selected slice in the CSO. A magnification of the white box is shown in C. (c) An example PVS rating: the green dots were scored as PVS.