Patent ID: 6841997

Claim:
A magnetic resonance tomography apparatus comprising: a magnetic resonance scanner adapted to receive a subject therein for exposing said subject to a basic magnetic field, exhibiting field inhomogeneities, and to a pulse sequence selected from the group consisting of spin echo pulse sequences and gradient echo pulse sequences, to excite a first spin ensemble and second spin ensemble in said subject, said first and second spin ensembles each exhibiting a magnetization and exhibiting respectively different chemical shift, said scanner obtaining nuclear magnetic resonance signals arising from both said first and second spin ensembles at respective echo times in said pulse sequence at which the respective magnetizations of said first and second spin ensembles reside perpendicularly, parallel and anti-parallel relative to each other; and a computer supplied with said nuclear magnetic resonance signals for Fourier transforming said nuclear magnetic resonance signals to obtain three complex images S 0 , S 1 and S 2 respectively for said echo times, each of said complex images representing a location-coded proton density of said first and second spin ensembles and containing a location-dependent evolution phase Φ 0 and different evolution phases Φ produced by said field inhomogeneities, said computer correcting said complex images for Φ 0 to obtain Φ 0 -corrected images and subsequently correcting said Φ 0 -corrected images for Φ to obtain fully corrected complex images, and assigning respective contributions in said fully corrected complex images to said first and second spin ensembles to calculate at least one of a pure image of said first spin ensemble and a pure image of said second spin ensemble.