Developing Topics.

Background: MR-visible perivascular space (PVS) burden is associated with clinical and MRI features of cerebrovascular disease. Its utility as an in vivo biomarker of post-mortem pathology is uncertain.

Method: Eighteen older adults (age at death 98.0, sd 5.5; 83% female) with autopsy consent were followed longitudinally in the Oregon Alzheimer's Disease Research Center with MRI and cognitive assessments until death. In vivo MR-visible white matter (WM) PVS volumes were derived using an automated segmentation algorithm based on T1 intensity thresholding and morphological constraints. Basal ganglia (BG) PVS were hand-traced on a single axial T1 slice with highest number of PVS. WM and BG PVS volumes were summed and normalized to brain volume to create a PVS score. General linear models (GLM) examined relationships between whole brain PVS score and: 1) cognition, and 2) post-mortem vascular pathologies. Models were adjusted for age, sex, and time between MRI and death when applicable.

Result: In vivo MRI PVS score was associated with greater post-mortem deep microvascular lesions (p = 0.002), arteriolosclerosis (p = 0.004), and atherosclerosis (p = 0.002). In separate models, PVS score was associated with worse performance on Trails B (p = 0.006) and MMSE (p = 0.02), but not memory (p = 0.6).

Conclusion: Greater whole brain in vivo PVS burden is associated with worse cognitive performance in domains commonly associated with cerebrovascular disease and multiple post-mortem cerebrovascular pathologies. Findings support the use of in vivo PVS as a candidate "V" marker in A/T/N classifications of older individuals.