Cerebrospinal fluid (CSF) is the fluid circulating through the subarachnoid space and providing a neuroprotective function as a hydraulic cushion for the brain and the spinal cord. CSF not only plays a vital role for normal brain function, but also servers numerous important functions in the central nervous system. However, CSF leaks are a key cause of new-onset headaches. Despite numerous reports characterizing CSF and its circulation in subarachnoid space, our understanding of CSF leakage remains limited. In this study, we calculate the CSF volumes in the brain and the spine of SIH patients using T2-weighted MRI images.