title: Evidence that cerebral blood volume can provide brain activation maps with better spatial resolution than deoxygenated hemoglobin.
abstract: With the aim of evaluating the relative performance of hemodynamic contrasts for mapping brain activity, the spatio-temporal response of oxy-, deoxy-, and total-hemoglobin concentrations were imaged with diffuse optical tomography during electrical stimulation of the rat somatosensory cortex. For both 6-s and 30-s stimulus durations, total hemoglobin images provided smaller activation areas than oxy- or deoxy-hemoglobin images. In addition, analysis of regions of interest near the sagittal sinus vein show significantly greater contrast in both oxy- and deoxy-relative to total hemoglobin, suggesting that oximetric contrasts have larger draining vein contributions compared to total hemoglobin contrasts under the given stimulus conditions. These results indicate that total hemoglobin and cerebral blood volume may have advantages as hemodynamic mapping contrasts, particularly for large amplitude, longer duration stimulus paradigms.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 4525 Scott Avenue, St. Louis, MO 63110, USA. culverj@wustl.edu
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Culver
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Siegel
authors.forename: Maria Angela
authors.initials: MA
authors.lastname: Franceschini
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Mandeville
authors.forename: David A
authors.initials: DA
authors.lastname: Boas
mesh_terms: D000465:Algorithms; D000818:Animals; D001810:Blood Volume / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004558:Electric Stimulation; D006439:Hemodynamics / Q000502:physiology; D006454:Hemoglobins / Q000737:chemistry* / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010108:Oxyhemoglobins / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014054:Tomography
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen