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Since Ogawa et al.(Proc Natl Acad Sci USA 1990; 87: 9868–9872) made the fundamental discovery of blood oxygenation leveldependent (BOLD) contrast in MRI, most efforts have been directed toward the study of dynamic BOLD (ie, temporal changes in the MRI signal during changes in brain activity). However, very little progress has been made in elucidating the nature of BOLD contrast during the resting or baseline state of the brain, which is important for understanding normal human performance because it accounts for most of the enormous energy budget of the brain. It is also crucial for deciphering the consequences of baseline-state impairment by cerebral vascular diseases. The objective of this study was to develop a BOLD MR-based method that allows quantitative evaluation of tissue hemodynamic parameters, such as the blood volume, deoxyhemoglobin concentration, and oxygen extraction fraction …