3D rigid-body motion information from spherical Lissajous navigators at small k-space radii: A proof of concept
| Autor: | Seong Dae Yun, Richard P. Buschbeck, N. Jon Shah |
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| Rok vydání: | 2018 |
| Předmět: |
Physics
Adult Male Rotation Phantoms Imaging Movement Mathematical analysis Spherical harmonics Motion (geometry) Motion detection Rigid body Magnetic Resonance Imaging Models Biological Imaging phantom 030218 nuclear medicine & medical imaging Lissajous curve 03 medical and health sciences 0302 clinical medicine Imaging Three-Dimensional Motion estimation Humans Radiology Nuclear Medicine and imaging Rotation (mathematics) 030217 neurology & neurosurgery Algorithms |
| Zdroj: | Magnetic resonance in medicine. 82(4) |
| ISSN: | 1522-2594 |
| Popis: | Purpose To demonstrate, for the first time, the feasibility of obtaining low-latency 3D rigid-body motion information from spherical Lissajous navigators acquired at extremely small k-space radii, which has significant advantages compared with previous techniques. Theory and methods A spherical navigator concept is proposed in which the surface of a k-space sphere is sampled on a 3D Lissajous curve at a radius of 0.1/cm. The navigator only uses a single excitation and is acquired in less than 5 ms. Rotation estimations were calculated with an algorithm from computer vision that exploits a rotation theorem of the spherical harmonics transform and has minimal computational cost. The effectiveness of the concept was investigated with phantom and in vivo measurements on a commercial 3T MRI scanner. Results Scanner-induced in vivo motion was measured with maximum absolute errors of 0.58° and 0.33 mm for rotations and translations, respectively. In the case of real, in vivo motion, the proposed method showed good agreement with motion information from FSL image registrations (mean/maximum deviations of 0.37°/1.24° and 0.44 mm/1.35 mm). In addition, phantom measurements indicated precisions of 0.014° and 0.013 mm. The computations for complete motion information took, on average, 24 ms on an ordinary laptop. Conclusions This work demonstrates a proof of concept for obtaining accurate motion information from small-radius spherical navigators. The method has the potential to overcome several previously reported problems and could help increase the utility of navigator-based motion correction both in research and in the clinic. |
| Databáze: | OpenAIRE |
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