Figure 3a:
Neurovascular response to breath hold. (a) Magnitude image intensity of superior sagittal sinus (SSS, box). Insets show velocity maps at different points of the velocity time-course (40 seconds [t40], 50 seconds [t50], and 70 seconds [t70]). (b) Sample SSS blood flow velocity time-course (red line) shown for a representative participant. The thick black line is linear fit during breath holds, the slope of which is the breath-hold index (BHI). ΔVSSS = post–breath hold relative velocity increase.