Calibrated BOLD: Measuring Task-Related Changes in CMRO2 at Baseline and Elevated CBF

Kevin Murphy¹, Ashley D. Harris¹, Richard G. Wise¹

By administering CO2 at two different levels, we show that calibrated BOLD techniques perform similarly in baseline conditions and at altered baseline CBF levels that simulate drug or disease effects on baseline brain physiology. We combined the hypercapnic challenge and task scans of calibrated BOLD techniques into a single acquisition. A 4mmHg increase in CO2 at baseline and elevated CBF levels yields similar estimates of task-related CMRO2 change. Verifying the performance of calibrated approaches at modified CBF levels renders calibrated BOLD techniques more pertinent to a clinical setting.