Cerebrospinal fluid (CSF) diffusion into periventricular white matter is one of the pathophysiological features of hydrocephalus of any kind. In standard clinical routine periventricular hyperintensities, size of the ventricular system, and invasive CSF pressure measurement are the key diagnostic methods. Recently a method called quantitative blood oxygenation level-dependent (qBOLD) was proposed by He and Yablonskiy (Magn Reson Med 2007;57:115-126), which uses the signal evolution of a GESSE sequence to extract quantitative information about hemodynamic parameters. In this study a similar method was used to extract volume fraction information of CSF and interstitial fluid (ISF) in the human brain. A standard gradient recalled echo / echo planar imaging (GRE-EPI) sequence with variable echo time was used for the acquisition of the MRI signal. A first test on healthy subjects yielded consistent results for ISF/CSF volume fraction, which were in good agreement with results found in the literature.