Volumetric navigators for prospective motion correction and selective reacquisition in neuroanatomical MRI.
We introduce a novel method of prospectively compensating for subject motion in neuroanatomical imaging. Short three-dimensional echo-planar imaging volumetric navigators are embedded in a long three-dimensional sequence, and the resulting image volumes are registered to provide an estimate of the subject's location in the scanner at a cost of less than 500 ms, ~ 1% change in contrast, and ~3% change in intensity. This time fits well into the existing gaps in sequences routinely used for neuroimaging, thus giving a motion-corrected sequence with no extra time required. We also demonstrate motion-driven selective reacquisition of k-space to further compensate for subject motion. We perform multiple validation experiments to evaluate accuracy, navigator impact on tissue intensity/contrast, and the improvement in final output. The complete system operates without adding additional hardware to the scanner and requires no external calibration, making it suitable for high-throughput environments.
Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA. tisdall@nmr.mgh.harvard.edu
M Dylan
MD
Tisdall
Aaron T
AT
Hess
Martin
M
Reuter
Ernesta M
EM
Meintjes
Bruce
B
Fischl
André J W
AJ
van der Kouwe
D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009038:Motion; D009485:Neuroradiography / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity