A Complexity Analysis for Normal Cerebral Blood and CSF Flow

Cerebro-spinal fluid (CSF) exhibits pulsatile flow due to systolic and diastolic blood flow in cerebral arteries and veins. We describe an investigation of the relationship between CSF flow and arterial & venous blood flow using principle component analysis (PCA). The study used Phase-Contrast Magnetic Resonance Images (PC-MRI) of 16 volunteers with no known CSF abnormalities. The immediate outcome is a linear model relating normal flows, which can be used as a comparative tool to identify abnormal flows due to disease. However, the PCA analysis also places an upper limit on the number of independent parameters required in any non-linear, physical model of the system. This could ultimately inform the development of such a model, allowing identification of the underlying biological mechanisms leading to abnormal flow in disease.