Meeting Banner
Abstract #4954

Open-Source Simulator for Spatial Encoding Effects in Highly Variable B0 and Gradient Fields

Radhika Tibrewala1,2,3, Christopher Collins1,2,3, Jan Paska1,2, Jakob Assländer1,2,3, and Daniel K Sodickson1,2,3
1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, 3Vilcek Institute of Graduate Biomedical Sciences, New York University Grossman School of Medicine, New York, NY, United States

Synopsis

Keywords: Hybrid & Novel Systems Technology, Simulations, spatial encoding

Motivation: Design of accessible scanners may require accounting for substantial magnetic field inhomogeneities, which challenge assumptions used in MRI simulators.

Goal(s): To capture the encoding effects of strong field variations accurately and efficiently, predicting distortions of input images.

Approach: We discretized magnetic fields as usual but extended the MR signal simulation at each grid point from the 0th-order approximation, which assumes a locally-constant field, to a 1st-order approximation, which assumes a locally-linear field.

Results: The 1st-order approximation, which has an analytic solution, better captures strongly varying fields and enables simulations on a coarser grid, greatly improving computational efficiency.

Impact: The simulator enables evaluation of scanner designs with strongly varying magnetic fields. Simulated images can be utilized to generate training data efficiently from existing ground-truth images, enabling exploration of machine-learning techniques prior to the construction of prototype systems.

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.

Click here for more information on becoming a member.

Keywords