Task-free presurgical mapping using functional magnetic resonance imaging intrinsic activity.
OBJECTIVE
Low-frequency components of the spontaneous functional MR imaging signal provide information about the intrinsic functional and anatomical organization of the brain. The ability to use such methods in individual patients may provide a powerful tool for presurgical planning. The authors explore the feasibility of presurgical motor function mapping in which a task-free paradigm is used.


METHODS
Six surgical candidates with tumors or epileptic foci near the motor cortex participated in this study. The investigators directly compared task-elicited activation of the motor system to activation obtained from intrinsic activity correlations. The motor network within the unhealthy hemisphere was identified based on intrinsic activity correlations, allowing distortions of functional anatomy caused by the tumor and epilepsy to be directly visualized. The precision of the motor function mapping was further explored in 1 participant by using direct cortical stimulation.


RESULTS
The motor regions localized based on the spontaneous activity correlations were quite similar to the regions defined by actual movement tasks and cortical stimulation. Using intrinsic activity correlations, it was possible to map the motor cortex in presurgical patients.


CONCLUSIONS
This task-free paradigm may provide a powerful approach to map functional anatomy in patients without task compliance and allow multiple brain systems to be determined in a single scanning session.
Liu
Hesheng
H
Massachusetts General Hospital/Massachusetts Institute of Technology/Harvard Medical School Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129, USA.
Buckner
Randy L
RL
Talukdar
Tanveer
T
Tanaka
Naoaki
N
Madsen
Joseph R
JR
Stufflebeam
Steven M
SM
D000293:Adolescent; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000473:pathology / Q000503:physiopathology; D002648:Child; D004558:Electric Stimulation; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006225:Hand / Q000294:innervation / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009044:Motor Cortex / Q000473:pathology* / Q000503:physiopathology; D011300:Preoperative Care / Q000379:methods*; D012680:Sensitivity and Specificity; D014059:Tongue / Q000294:innervation / Q000502:physiology; D055815:Young Adult