Reduction of susceptibility artifacts in subencoded single-shot magnetic resonance imaging
AssigneeKoninklijke Philips Electronics N.V.
InventorsThomas Jaermann, Klaas Paul Pruessmann, Markus Weiger, Conny Frauke Schmidt, Peter Boesiger
Life of this patent
Estimating the term…
Abstract
In a magnetic resonance imaging method an echo train is generated of successive magnetic resonance signals from an object to be examined. The magnetic resonance signals are received with a degree of undersampling and by means of a receiver antennae system having a spatial sensitivity profile and the degree of undersampling is set on the basis of an amount of phase evolution due to a magnetic susceptibility distribution of the object to be examined.
Claims6
A magnetic resonance imaging method comprising:
- applying a static main magnetic field with a main field strength;
- applying an acquisition sequence with an RF-excitation which generates an echo train of successive magnetic resonance signals from an object to be examined, the acquisition sequence including a diffusion sensitization subsequence;
- receiving the magnetic resonance signals with a degree of undersampling by means of a receiver antennae system having a spatial sensitivity profile, the degree of undersampling is set on the basis of an amount of phase evolution due to a magnetic susceptibility distribution of the object to be examined;
- reconstructing a magnetic resonance image from the magnetic resonance signals and the spatial sensitivity profile;
- repeatedly applying the excitation sequence, receiving the magnetic resonance signals and reconstructing the magnetic resonance image to produce a series of magnetic resonance images;
- matching said magnetic resonance images and determining mutual matches between said magnetic resonance images;
- selecting a number of the magnetic resonance images from the series on the basis of the mutual matches;
- averaging over said selected number magnetic resonance images.
A computer processor or media programmed to perform the steps of:
- repeatedly applying an excitation sequence, receiving resultant magnetic resonance signals, and reconstructing the magnetic resonance signals to produce a series of magnetic resonance images;
- comparing the magnetic resonance images of the series to determine images with at least a preselected degree of similarity;
- combining the magnetic resonance images of the series which have at least the preselected degree of similarity.
A magnetic resonance imaging system including a main magnet which applies a static magnetic field, an RF coil, a transmitter for applying an acquisition sequence with an RF excitation which generates an echo train of successive magnetic resonance signals from an object to be examined, a receiver antenna system having a spatial sensitivity profile, a receiver for receiving magnetic resonance signals with a degree of undersampling from the receiver antenna system, and a controller, the controller being programmed to:
- selectively adjust the degree of undersampling in accordance with an amount of phase evolution artifacting attributable to a magnetic susceptibility distribution of the object to be examined.
Dependencies are inferred from the claim text.