A novel early imaging biomarker for glymphatic function: Cerebral cortical arterial pulsatility index from 2-Minute...

Arterial pulsatility is one of the driving forces of glymphatic flow.

To evaluate the feasibility of the pulsatility index (PI) of cortical arteries in the centrum semiovale (PI_CSO) as a novel non-invasive imaging biomarker for Alzheimer's disease (AD) in the context of glymphatic function.

Retrospective cross-sectional study.

Single tertiary academic center equipped with both 3.0 T MRI systems.

A total of 160 individuals were enrolled: 50 healthy volunteers, 46 cognitively normal controls, and 64 AD patients who underwent diffusion tensor imaging (DTI) and 2D phase-contrast MRI.

Diffusion Tensor Imaging Analysis along the Perivascular Space (DTI-ALPS) index and PI_CSO were assessed using 2D phase-contrast MRI. Correlations with age, DTI-ALPS index, and Mini-Mental State Examination (MMSE) scores were analyzed.

PI_CSO was significantly higher in the AD group than those in healthy volunteers (P<0.001) and cognitively normal aging (P=0.001) groups. PI_CSO correlated positively with age (rho=0.613, P<0.001) and negatively with both the DTI-ALPS index (rho=-0.439, P<0.001) and MMSE scores (rho=-0.486, P<0.001) in total group.

PI_CSO derived from 2D phase-contrast 3.0T MRI may serve as a novel imaging biomarker for Alzheimer's disease in relation to glymphatic function.