Magnetic resonance imaging with bipolar multi-echo sequences

A method for magnetic resonance imaging (MRI), comprising:

• a) applying a magnetic resonance excitation in a MRI apparatus, comprising an imaging excitation and detection system and a controller, which controls the imaging excitation and detection system;
• b) acquiring a plurality of k-space echoes bi-directionally wherein at least one echo is an even echo acquired in a first direction and at least one echo is an odd echo acquired in a second direction opposite from the first direction, in the imaging excitation and detection system;
• c) correcting k-space echo realignment between the even and odd echoes in the controller, wherein the correcting the k-space echo realignment is performed in k-space, wherein the correcting the k-space echo realignment comprises performing a one-dimensional search algorithm to minimize a cross-correlation coefficient;
• d) correcting field inhomogeneity induced artifacts in the controller, wherein the correcting field inhomogeneity is performed in image space;
• e) correcting chemical shift induced artifacts between at least two species in the controller, wherein the correcting chemical shift induced artifacts is performed in k-space;
• and
• f) generating an image using the correction k-space echo realignment in the controller, correction field inhomogeneity, and correction chemical shift.

A method for magnetic resonance imaging (MRI), comprising:

• a) applying a magnetic resonance excitation in a MRI apparatus, comprising an imaging excitation and detection system and a controller, which controls the imaging excitation and detection system;
• b) acquiring a plurality of k-space echoes bi-directionally, in the imaging excitation and detection system, wherein at least one echo is an even echo acquired in a first direction and at least one echo is an odd echo acquired in a second direction opposite from the first direction;
• c) correcting k-space echo realignment between the even and odd echoes in the controller, wherein the correcting the k-space echo realignment is performed in k-space;
• d) correcting field inhomogeneity induced artifacts in the controller, wherein the correcting field inhomogeneity is performed in image space;
• e) correcting chemical shift induced artifacts between at least two species in the controller, wherein the correcting chemical shift induced artifacts is performed in k-space;
• f) separating a number of species more than two species, wherein the number of the plurality of echoes is at least the number of species in the controller;
• and
• g) generating an image using the correction k-space echo realignment, correction field inhomogeneity, and correction chemical shift in the controller.

A magnetic resonance imaging apparatus, comprising:

• a magnetic resonance imaging excitation and detection system;
• and
• a controller electrically connected to the magnetic resonance imaging excitation and detection system, comprising:
• a display;
• at least one processor;
• and
• computer readable media, comprising:
• computer readable code for applying a magnetic resonance excitation;
• computer readable code for acquiring a plurality of k-space echoes bi-directionally wherein at least one echo is an even echo acquired in a first direction and at least one echo is an odd echo acquired in a second direction opposite from the first direction;
• computer readable code for correcting k-space echo realignment between the even and odd echoes;
• computer readable code for correcting field inhomogeneity induced artifacts;
• and
• computer readable code for simultaneously correcting chemical shift induced artifacts between at least two species.