Fig. 6: Hypothesis model on physiological mechanisms of laminar changes in arterial pulsatility.
From: Assessing cerebral microvascular volumetric with high-resolution 4D cerebral blood volume MRI at 7 T
a, Potential physiological mechanisms of arterial pulsatility changes with laminae in normal or abnormal brain. The blue box at the top of the image illustrates the physiological mechanisms underlying the changes in vPI and vePI across arteries in young, healthy brains. Upward-pointing arrows indicate that these parameters increase along the arterial transmission pathway, whereas downward-pointing arrows signify a decrease. Conversely, the red box at the bottom of the image depicts the mechanisms of abnormal vPI and vePI in elderly or pathological brains. In this context, red arrows indicate an increase in parameters relative to healthy brains, whereas blue arrows denote a decrease. b, The laminar profiles distribution of arterial total volume, blood pressure, predicated vPI (including mvPI and voPI) and vePI in young and elderly individuals predicted by the hypothetical model.
