ABSTRACT
The impact of functional magnetic resonance imaging (fMRI) on neuroscience has been vast since the earliest human experiments conducted at Medical College of Wisconsin, Yale University, Max Planck Institute, Massachusetts General Hospital, and University of Minnesota (Bandettini et al., 1992; Blamire et al., 1992; Frahm et al., 1992; Kwong et al., 1992; Ogawa et al., 1992). But shortly after these 1992 fMRI studies, there were concerns about how well the blood oxygenation level-dependent (BOLD) signal reflected underlying changes in neural activity (Barinaga, 1997). As described below, the component of the BOLD contrast that best correlates with neural activity is the change in oxygen consumption (ΔCMRO2). A field of quantitative MRI emerged as a consequence to convert the BOLD response into a quantitat ive measure of the oxidative energy consumed during brain function [for a historical perspective, see Hyder and Rothman (2012)].
