Prospective multiaxial motion correction for fMRI

Corruption of the image time series due to interimage head motion limits the clinical utility of functional MRI. This paper presents a method for real‐time prospective correction of rotation and translation in all six degrees of rigid body motion. By incorporating an orbital navigator (ONAV) echo for each of the sagittal, axial, and coronal planes into the fMRI pulse sequence, rotation and translation can be measured and the spatial orientation of the image acquisition sequence that follows can be corrected prospectively in as little as 160 msec. Testing of the method using a computerized motion phantom capable of performing complex multiaxial motion showed subdegree rotational and submillimeter translational accuracy over a range of ±8° and ±8 mm of motion. In vivo images demonstrate correction of simultaneous through‐plane and in‐plane motion and improved detection of fMRI activation in the presence of head motion. Magn Reson Med 43:459–469, 2000. © 2000 Wiley‐Liss, Inc.