Fig. 5: vePI and voPI calculation and results from 4D-flow dataset.
From: Assessing cerebral microvascular volumetric with high-resolution 4D cerebral blood volume MRI at 7 T
a, Schematic diagram of the ROI selection position of a typical subject in the circle of Willis. The lower left corner is the sagittal plane image within the black frame. b, The cardiac phase profile of velocity and cross-sectional area obtained by ICA from a random participant. c, The vePI and voPI results in both age groups within all MCA ROIs. The top image is the results of vePI, and the bottom one is the results of voPI. Red is for older participants, and blue is for young participants. The circles are the results for each participant, and the horizontal line is the average of this group of data. Statistical significance was assessed using a two-sided bootstrap test (10,000 resamples). Bonferroni correction, factor = 3. Exact P values are shown in the figure (young n = 9 and older n = 12 independent biological replicates). Error bars indicate s.e.m. across participants. d, Relationship between mvPI in deep WM and vePI in ICA and MCA1. The shading is the 95% confidence interval, and dots represent individual participants. n = 20 independent biological replicates. R2 indicates how much of the variance in the dependent variable is explained by the independent variable. e, Changes of vPI (including mvPI and voPI) as the cerebral vasculature in MCA territory. The blue and red curves represent the results for young and older participants, respectively. The light blue shaded area indicates the WM area, and the light green shaded area indicates the pial mater area. WMd and WMs on the x axis represent the deep WM and superficial WM. The values on the x axis from 1 to 0 represent the GM from deep to superficial. M1, M2 and M3 represent the MCA1, MCA2 and MCA3 segment. Young n = 9 and older n = 11 independent biological replicates. Error bars indicate s.e.m. across participants.
