Keywords: System Imperfections, System Imperfections: Measurement & Correction, Data Acquisition, Data Processing, Gradients, Image Reconstruction
Motivation: For EPI, beat phenomena can occur and result in a slowly varying, erroneous phase component caused by mechanical resonances of the gradient system. Current phase correction approaches do not account for this error.
Goal(s): Improving EPI correction by characterization of gradient-induced, time-varying errors of zeroth and first spatial order.
Approach: EPI image projections of a spherical phantom were acquired by omitting the phase encoding blips. The resulting x-ky-data enable a characterization of zeroth- and first-order effects separately.
Results: The mechanical properties of the gradient system result in a transient state during which an erroneous, temporally and spatially modulated magnetic field gradient occurs.
Impact: EPI is a widely applied fast imaging technique but sensitive to gradient-induced magnetic field deviations. Therefore, phase correction is of utmost importance and may be improved by the proposed characterization of slowly varying, erroneous phases.
How to access this content:
For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.
After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.
After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.
Keywords