ABSTRACT
The blood oxygen level–dependent (BOLD) signal is a powerful neuroimaging tool that assesses the hemodynamic response to functional activity. To accurately interpret the BOLD signal and compare between patients, however, requires a quantitative and specific understanding of its physiological sub-components. This chapter describes advanced MRI sequences to measure these sub-components, including cerebral blood flow, cerebral blood volume, cerebrovascular reactivity, and task-evoked and baseline oxygenation. For each physiological quantity, the contrast mechanism of MRI acquisition, analysis strategy, and relative advantages and disadvantages of multiple approaches are compared. Accepted ranges for quantitative cerebral physiology parameters and their applications in neurological disease are reported, with a focus on future technical development to improve robustness and clinical utility of these measurements.
