DiSpect Consistently and Repeatably Reveals Modulation and Redistribution of Venous Blood Flow Caused by Functional Brain Activation

Motivation: DiSpect can trace blood draining from the capillary bed through the cerebral venous system and map venous territories. Goal(s): Determine whether DiSpect can detect blood flow changes in the veins during neural activation. Approach: DiSpect was performed during a motor cortex task and at baseline for two subjects, each with two repeats to ensure consistency and repeatability. Results: Modulation and redistribution of flow were observed during the task, specifically in veins near the BOLD fMRI activated regions. The measurements showed good repeatability for both subjects. Impact: BOLD contrast is affected by a complex interplay of several physiological processes. DiSpect measures changes in venous blood flow dynamics during neural activation and can potentially help to better understand the venous sources of the BOLD signal.