U.S. Philips Corporation

Jens D Jensen

Peter R Luyten

Ingwer C Carlsen

Wolfgang Vollmann

An MR method is presented for determining the nuclear magnetization distribution in an examination zone, the image data acquired during an MR examination by means of a surface coil arrangement, comprising at least one coil and exhibiting a locally inhomogeneous sensitivity, being corrected on the basis of auxiliary values derived from data acquired by means of a body coil arrangement having a locally at least approximately homogeneous sensitivity. Improved reconstruction is achieved in that, in addition to the MR examination, a respective MR auxiliary measurement is performed by means of the surface coil arrangement as well as by means of the body coil arrangement, that the two MR auxiliary measurements are carried out temporally separated from one another and from the MR examination, that during the two MR auxiliary measurements the magnetic fields acting on the examination zone exhibit the same variation in time, and that the auxiliary values are derived from the data acquired during the two MR auxiliary measurements.

Method for reducing inhomogeneity of surface coils through additional

A magnetic resonance imaging method for generating separate fat and water images of at least one slice utilizes a plurality of sequences acting on the slice in the presence of a steady magnetic field, each sequence including at least one first RF pulse, followed by a phase encoding gradient during which the spin resonance signal formed in the slice is detected, groups of sequences being formed with a position in time of the measuring gradient and/or a further RF pulse, if any, which differs from one group to another, the number of sequences per slice being twice as large as necessary for the formation of a similar image without fat/water separation. The phase encoding gradient is varied in steps from one sequence to another. The separate fat and water images (F,W) are formed from the resultant spin resonance signals by 2D Fourier transformation.

Magnetic resonance tomography method for generating separate fat and

An improved MRI sequence for suppressing a signal from a chemical shift component avoids image artifacts due to relatively large rf fields inhomogeneities as may be caused by using linearly polarized rf fields by selectively inverting the chemical shift component by means of an adiabatic fast passage rf pulse prior to spin echo excitation.

Magnetic resonance method and device for suppressing a signal from a

The invention relates to a fast method for the formation of a set of survey images of the nuclear magnetization in adjoining slices. First the nuclear magnetization in orthogonal slices which extend perpendicularly to the slices is excited during a plurality of successive cycles. Then the nuclear magnetization distribution for the individual slices is derived from the nuclear magnetization distribution of the orthogonal slices. Comparatively short measuring times can be achieved by means of such a method.

Magnetic resonance tomography method for determining the nuclear

The invention relates to a magnetic resonance tomography method where two slice-selective rf pulses influence the nuclear magnetization in a slice. Further slice selective rf pulses which excite sub-slices extending perpendicularly to said slice generate stimulated echo signals in the strip-shaped zone of intersection between the relevant sub-slice and the slice. The FID signals associated with the further rf pulses are suppressed by means of a subsequently activated magnetic gradient field. In order to ensure that this field does not dephase the desired stimulated echo signals at the same time magnetic gradient field having the same time integral is activated between the first and the second rf pulse.

Growing community of inventors

Hamburg, Germany

Jens D Jensen