Abstract #2921

Spatial Field Monitoring using Navigator Echoes

Maarten J. Versluis^1,2, Andrew G. Webb^1,2, Peter Boernert^2,3, Mark A. van Buchem¹, Matthias J. P. van Osch^1,2

¹Radiology, Leiden University Medical Center, Leiden, Netherlands; ²C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands; ³Philips Research Europe, Hamburg, Germany

Strongly T₂^*-weighted sequences are very sensitive to variations in the magnetic field due to, for example, respiration and body movements. This effect is more apparent at high magnetic field strengths (7 Tesla). Using navigator echoes it is possible to estimate and correct for global field changes. In this work we have improved this method by including the sensitivities of the different coil elements in the receive array to estimate the local field variations. Including the spatial encoding along the read out axis of the navigators yielded the best results.