Extended Data Fig. 9: Schematic diagram of arterial pulsation and results of other ROI sites in 4D-flow scan.
From: Assessing cerebral microvascular volumetric with high-resolution 4D cerebral blood volume MRI at 7 T
a, Schematic diagram of arterial pulsation in large (MCA1, upper row) and small (MCA3, lower row) arteries. The first and second columns display magnitude images captured at the systole and the end of diastole, respectively, with the arterial boundaries delineated using blue and red lines. The third column displays zoomed-in images comparing the arterial boundaries between these two cardiac phases. b, The velocity pulsatility index (vePI) and volumetric pulsatility index (voPI) results in both age groups in all ROI sites except MCA. The top image is the results of vePI, and the bottom one is the results of voPI. Red is for older subjects and blue is for young subjects. 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). Young n = 9 and older n = 12 independent biological replicates, representing individual human participants, each measured once. Exact uncorrected p values are shown in the figure. Error bars indicate SEM across participants.
