Real-time correction of rigid body motion-induced phase errors for diffusion-weighted steady-state free precession imaging.
OBJECTIVE
Diffusion contrast in diffusion-weighted steady-state free precession magnetic resonance imaging (MRI) is generated through the constructive addition of signal from many coherence pathways. Motion-induced phase causes destructive interference which results in loss of signal magnitude and diffusion contrast. In this work, a three-dimensional (3D) navigator-based real-time correction of the rigid body motion-induced phase errors is developed for diffusion-weighted steady-state free precession MRI.


METHODS
The efficacy of the real-time prospective correction method in preserving phase coherence of the steady state is tested in 3D phantom experiments and 3D scans of healthy human subjects.


RESULTS
In nearly all experiments, the signal magnitude in images obtained with proposed prospective correction was higher than the signal magnitude in images obtained with no correction. In the human subjects, the mean magnitude signal in the data was up to 30% higher with prospective motion correction than without. Prospective correction never resulted in a decrease in mean signal magnitude in either the data or in the images.


CONCLUSIONS
The proposed prospective motion correction method is shown to preserve the phase coherence of the steady state in diffusion-weighted steady-state free precession MRI, thus mitigating signal magnitude losses that would confound the desired diffusion contrast.
Department of Radiology, Stanford University, Stanford, California, USA.
Rafael
R
O'Halloran
Murat
M
Aksoy
Eric
E
Aboussouan
Eric
E
Peterson
Anh
A
Van
Roland
R
Bammer
D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D003199:Computer Systems; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D009038:Motion; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
diffusion; diffusion tensor imaging (DTI); diffusion-weighted imaging (DWI); motion-correction; navigation; phase; steady-state free precession