<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>Functional magnetic resonance imaging (fMRI) is a quickly developing method for non-invasive dynamic brain studies. It uses swift acquisition sequences like echo planar imaging (EPI) that are very sensitive to susceptibility artifacts. These artifacts relate to magnetic field inhomogeneities and may cause geometric distortions. Many methods for correcting these distortions are currently used. Most common are the field mapping methods that use the map of field strength. To create a field map, different approaches can be used and different data must be acquired for each method. This paper compares a commonly used conventional gradient echo (GE) field mapping method with a 3EPI phase images based method. Although the EPI method is more sophisticated and was expected to perform better, the GE field maps showed better results in distortion correction. The cause of this is not in the method's principle itself, but in its high requirements.</p></abstract>

Functional magnetic resonance imaging (fMRI) is a quickly developing method for non-invasive dynamic brain studies. It uses swift acquisition sequences like echo planar imaging (EPI) that are very sensitive to susceptibility artifacts. These artifacts relate to magnetic field inhomogeneities and may cause geometric distortions. Many methods for correcting these distortions are currently used. Most common are the field mapping methods that use the map of field strength. To create a field map, different approaches can be used and different data must be acquired for each method. This paper compares a commonly used conventional gradient echo (GE) field mapping method with a 3EPI phase images based method. Although the EPI method is more sophisticated and was expected to perform better, the GE field maps showed better results in distortion correction. The cause of this is not in the method's principle itself, but in its high requirements.

Method for geometric distortion correction in fMRI based on three echo planar phase images

Institute of Measurement Science, Slovak Academy of Sciences, Dubravska cesta 9, 841 04, Bratislava, Slovakia

MR Center of Excellence, Medical University of Vienna, Lazarettgasse 14, A-1090 Vienna, Austria

Center for Biomedical Engineering and Physics, Medical University of Vienna, Austria

Measurement Science Review

Functional magnetic resonance imaging (fMRI) is a quickly developing method for non-invasive dynamic brain studies. It uses swift acquisition sequences like...

Method for geometric distortion correction in fMRI based on three echo planar phase images

Published Online: Oct 28, 2010

Page range: 116 - 119

DOI: https://doi.org/10.2478/v10048-010-0022-6

Keywords
Field map, distortion correction, fMRI

This content is open access.

Method for geometric distortion correction in fMRI based on three echo planar phase images

Published Online: Oct 28, 2010

Page range: 116 - 119

DOI: https://doi.org/10.2478/v10048-010-0022-6

KeywordsField map, distortion correction, fMRI

This content is open access.

Keywords
Field map, distortion correction, fMRI