Feasibility of spiral fMRI based on an LTI gradient model
Spiral imaging is very well suited for functional MRI, however its use has been limited by the fact that artifacts caused by gradient imperfections and B0 inhomogeneity are more difficult to correct compared to EPI. Effective correction requires accurate knowledge of the traversed k-space trajectory...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Elsevier
2021
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| _version_ | 1797098818993389568 |
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| author | Graedel, NN Kasper, L Engel, M Nussbaum, J Wilm, BJ Pruessmann, KP Vannesjo, SJ |
| author_facet | Graedel, NN Kasper, L Engel, M Nussbaum, J Wilm, BJ Pruessmann, KP Vannesjo, SJ |
| author_sort | Graedel, NN |
| collection | OXFORD |
| description | Spiral imaging is very well suited for functional MRI, however its use has been limited by the fact that artifacts caused by gradient imperfections and B0 inhomogeneity are more difficult to correct compared to EPI. Effective correction requires accurate knowledge of the traversed k-space trajectory. With the goal of making spiral fMRI more accessible, we have evaluated image reconstruction using trajectories predicted by the gradient impulse response function (GIRF), which can be determined in a one-time calibration step.
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GIRF-predicted reconstruction was tested for high-resolution (0.8 mm) fMRI at 7T. Image quality and functional results of the reconstructions using GIRF-prediction were compared to reconstructions using the nominal trajectory and concurrent field monitoring.
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The reconstructions using nominal spiral trajectories contain substantial artifacts and the activation maps contain misplaced activation. Image artifacts are substantially reduced when using the GIRF-predicted reconstruction, and the activation maps for the GIRF-predicted and monitored reconstructions largely overlap. The GIRF reconstruction provides a large increase in the spatial specificity of the activation compared to the nominal reconstruction.
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The GIRF-reconstruction generates image quality and fMRI results similar to using a concurrently monitored trajectory. The presented approach does not prolong or complicate the fMRI acquisition. Using GIRF-predicted trajectories has the potential to enable high-quality spiral fMRI in situations where concurrent trajectory monitoring is not available. |
| first_indexed | 2024-03-07T05:15:07Z |
| format | Journal article |
| id | oxford-uuid:dce6c11b-5e0f-4f02-a4cf-ee0159f9a9b7 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T05:15:07Z |
| publishDate | 2021 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:dce6c11b-5e0f-4f02-a4cf-ee0159f9a9b72022-03-27T09:21:08ZFeasibility of spiral fMRI based on an LTI gradient modelJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:dce6c11b-5e0f-4f02-a4cf-ee0159f9a9b7EnglishSymplectic ElementsElsevier2021Graedel, NNKasper, LEngel, MNussbaum, JWilm, BJPruessmann, KPVannesjo, SJSpiral imaging is very well suited for functional MRI, however its use has been limited by the fact that artifacts caused by gradient imperfections and B0 inhomogeneity are more difficult to correct compared to EPI. Effective correction requires accurate knowledge of the traversed k-space trajectory. With the goal of making spiral fMRI more accessible, we have evaluated image reconstruction using trajectories predicted by the gradient impulse response function (GIRF), which can be determined in a one-time calibration step. <br> GIRF-predicted reconstruction was tested for high-resolution (0.8 mm) fMRI at 7T. Image quality and functional results of the reconstructions using GIRF-prediction were compared to reconstructions using the nominal trajectory and concurrent field monitoring. <br> The reconstructions using nominal spiral trajectories contain substantial artifacts and the activation maps contain misplaced activation. Image artifacts are substantially reduced when using the GIRF-predicted reconstruction, and the activation maps for the GIRF-predicted and monitored reconstructions largely overlap. The GIRF reconstruction provides a large increase in the spatial specificity of the activation compared to the nominal reconstruction. <br> The GIRF-reconstruction generates image quality and fMRI results similar to using a concurrently monitored trajectory. The presented approach does not prolong or complicate the fMRI acquisition. Using GIRF-predicted trajectories has the potential to enable high-quality spiral fMRI in situations where concurrent trajectory monitoring is not available. |
| spellingShingle | Graedel, NN Kasper, L Engel, M Nussbaum, J Wilm, BJ Pruessmann, KP Vannesjo, SJ Feasibility of spiral fMRI based on an LTI gradient model |
| title | Feasibility of spiral fMRI based on an LTI gradient model |
| title_full | Feasibility of spiral fMRI based on an LTI gradient model |
| title_fullStr | Feasibility of spiral fMRI based on an LTI gradient model |
| title_full_unstemmed | Feasibility of spiral fMRI based on an LTI gradient model |
| title_short | Feasibility of spiral fMRI based on an LTI gradient model |
| title_sort | feasibility of spiral fmri based on an lti gradient model |
| work_keys_str_mv | AT graedelnn feasibilityofspiralfmribasedonanltigradientmodel AT kasperl feasibilityofspiralfmribasedonanltigradientmodel AT engelm feasibilityofspiralfmribasedonanltigradientmodel AT nussbaumj feasibilityofspiralfmribasedonanltigradientmodel AT wilmbj feasibilityofspiralfmribasedonanltigradientmodel AT pruessmannkp feasibilityofspiralfmribasedonanltigradientmodel AT vannesjosj feasibilityofspiralfmribasedonanltigradientmodel |