title: Spatiotemporal magnetic field monitoring for MR.
abstract: MR experiments frequently rely on signal encoding by the application of magnetic fields that vary in both space and time. The accurate interpretation of the resulting signals often requires knowledge of the exact spatiotemporal field evolution during the experiment. To better fulfill this need, a new approach is presented that enables measuring the field evolution concurrently with any MR sequence. Miniature NMR probes are used to monitor the MR phase evolution around the object under investigation. Based on these data, a global phase model is calculated that can then be used as a basis for processing the actual image or spectroscopic data. The new method is demonstrated by MRI of a phantom, using spin-warp, spiral, and EPI trajectories. Throughout, the monitoring results enabled highly accurate image reconstruction, even in the presence of massive gradient imperfections.
authors.affiliation: Institute for Biomedical Engineering of the University, ETH Zurich, Department of Information Technology and Electrical Engineering, Gloriastrasse 35, Zurich, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Barmet
authors.forename: Nicola
authors.initials: N
authors.lastname: De Zanche
authors.forename: Klaas P
authors.initials: KP
authors.lastname: Pruessmann
mesh_terms: D002138:Calibration; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D008962:Models, Theoretical; D019047:Phantoms, Imaging