Article ID Journal Published Year Pages File Type
1806095 Magnetic Resonance Imaging 2016 9 Pages PDF
Abstract

PurposeTo develop and evaluate a rapid spherical navigator echo (SNAV) motion correction technique, then apply it for retrospective correction of brain images.MethodsThe pre-rotated, template matching SNAV method (preRot-SNAV) was developed in combination with a novel hybrid baseline strategy, which includes acquired and interpolated templates. Specifically, the SNAV templates are only rotated around X- and Y-axis; for each rotated SNAV, simulated baseline templates that mimic object rotation about the Z-axis were interpolated.The new method was first evaluated with phantom experiments. Then, a customized SNAV-interleaved gradient echo sequence was used to image three volunteers performing directed head motion. The SNAV motion measurements were used to retrospectively correct the brain images. Experiments were performed using a 3.0 T whole-body MRI scanner and both single and 8-channel head coils.ResultsPhantom rotations and translations measured using the hybrid baselines agreed to within 0.9° and 1 mm compared to those measured with the original preRot-SNAV method. Retrospective motion correction of in vivo images using the hybrid preRot-SNAV effectively corrected for head rotation up to 4° and 4 mm.ConclusionsThe presented hybrid approach enables the acquisition of pre-rotated baseline templates in as little as 2.5 s, and results in accurate measurement of rotations and translations. Retrospective 3D motion correction successfully reduced motion artifacts in vivo.

Related Topics
Physical Sciences and Engineering Physics and Astronomy Condensed Matter Physics
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