Determination of a pulse sequence for a magnetic resonance system

Patent metadata

Field	Value
Publication number	US-9632160-B2
Application number	US-201414182538-A
Country	US
Kind code	B2
Filing date	Feb 18, 2014
Priority date	Feb 18, 2013
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

In a method and a pulse sequence determination device to determine a pulse sequence for a magnetic resonance system, control protocol parameter values are initially acquired. A determination of k-space trajectory node points within k-space then takes place in a processor on the basis of the control protocol parameter values. The determination of the pulse sequence then takes place on the basis of the k-space trajectory node points. A method for operating a magnetic resonance system uses such a pulse sequence, and a magnetic resonance system embodies such a pulse sequence determination device.

First claim

We claim as our invention:

1. A method to determine a pulse sequence for operating a magnetic resonance system, comprising:
providing control protocol parameters to a processor that define operational features of said magnetic resonance system in order to acquire magnetic resonance data from a subject, said control protocol parameters being selected from the group consisting of a sequence type of a pulse sequence for operating said magnetic resonance system to acquire said magnetic resonance data from the subject, an echo time in said pulse sequence, a repetition time of said pulse sequence, a resolution of said magnetic resonance data, a readout bandwidth of said magnetic resonance data, and a target magnetization of nuclear spins in the subject;
in said processor, automatically determining, dependent on said control protocol parameter values, a plurality of k-space trajectory node points of a trajectory that will be traversed in k-space in order to enter said magnetic resonance data into k-space, said trajectory comprising a plurality of trajectory branches that are successively traversed in said trajectory, each branch having a starting point in k-space and an ending point in k-space and each node point coinciding with one of the respective starting points or ending points; and
in said processor, for each k-space trajectory node point, determining a node point time associated therewith that is a time, following a start of said trajectory, at which said magnetic resonance data are entered at the respective k-space trajectory node point, dependent on at least some of said control parameter values;
in said processor, determining respective k-space trajectories, and curves of a gradient pulse series, needed to reach the respective k-space trajectory node point at the respective trajectory node point time associated therewith; and
in said processor, determining said pulse sequence for operating said magnetic resonance system based on said plurality of k-space trajectory node points and said curves of said gradient pulse series, and making said pulse sequence available at an output of said processor in electronic form with a format for operating said magnetic resonance system.

2. A method as claimed in claim 1 comprising selecting at least some of said k-space trajectory node points to coincide with a time of occurrence at least one defined event in the operation of said magnetic resonance system selected from the group consisting of emission of a radio-frequency pulse and activating a readout gradient during which said magnetic resonance data are acquired from the subject.

3. A method as claimed in claim 1 comprising providing said processor with system specification parameter values that define physical attributes of said magnetic resonance system and, in said processor, determining said pulse sequence also dependent on said system specification parameter values.

4. A method as claimed in claim 1 comprising providing said processor, as one of said protocol parameter values, with a designation of a sequence type for said pulse sequence, said sequence type requiring auxiliary gradient moments for gradient pulses in said pulse sequence, and determining said pulse sequence in said processor also dependent on said auxiliary gradient moments.

5. A method as claimed in claim 1 comprising, in said processor, after determining said k-space trajectory node points then determining, for each k-space trajectory node point:
(a) a minimum of the k-space trajectory node point time respectively associated therewith;
(b) determine adjustable parameter value ranges for at least one of said control protocol parameter values;
(c) present the adjustable parameter value ranges at a display monitor in communication with said processor and thereafter detecting change commands entered into said processor that change any of said control protocol parameter values;
(d) checking each minimum node point time dependent on any changed control protocol parameter values to obtain a check result;
if said check result indicates any of said possible minimum node point times is not achievable, repeating (a), (b), (c) and (d); and
if said check result indicates said minimum node point times are achievable, determining said pulse sequence based on said k-space trajectory node points respectively associated with the possible minimum node point times.

6. A method as claimed in claim 1 comprising entering said k-space trajectory node points via a user interface of said processor.

7. A method as claimed in claim 1 comprising, in said processor, determining at least one of said pulse sequence and said k-space trajectory node points using a programming language that is independent of said magnetic resonance system.

8. A method as claimed in claim 1 comprising, in said processor, determining at least one of said pulse sequence and said k-space trajectory node points using a scripting language.

9. A method to operate a magnetic resonance system, comprising:
providing control protocol parameters to a processor that define operational features of said magnetic resonance system in order to acquire magnetic resonance data from a subject, said control protocol parameters being selected from the group consisting of a sequence type of a pulse sequence for operating said magnetic resonance system to acquire said magnetic resonance data from the subject, an echo time in said pulse sequence, a repetition time of said pulse sequence, a resolution of said magnetic resonance data, a readout bandwidth of said magnetic resonance data, and a target magnetization of nuclear spins in the subject;
in said processor, automatically determining, dependent on said control protocol parameter values, a plurality of k-space trajectory node points of a trajectory that will be traversed in k-space in order to enter said magnetic resonance data into k-space, said trajectory comprising a plurality of trajectory branches that are successively traversed in said trajectory, each branch having a starting point in k-space and an ending point in k-space and each node point coinciding with one of the respective starting points or ending points; and
in said processor, for each k-space trajectory node point, determining a node point time associated therewith that is a time, following a start of said trajectory, at which said magnetic resonance data are entered at the respective k-space trajectory node point, dependent on at least some of said control parameter values;
in said processor, detennining respective k-space trajectories, and curves of a gradient pulse series, needed to reach the respective k-space trajectory node point at the respective trajectory node point time associated therewith;
in said processor, determining said pulse sequence for operating said magnetic resonance system based on said plurality of k-space trajectory node points and said curves of said gradient pulse series, and making said pulse sequence available at an output of said processor in electronic form with a format for operating said magnetic resonance system; and
operating said magnetic resonance system according to said pulse sequence.

10. A pulse sequence determination device for determining a pulse sequence to operate a magnetic resonance system, said pulse sequence determination device comprising:
a processor having an interface provided with control protocol parameters that define operational features of said magnetic resonance system in order to acquire magnetic resonance data from a subject, said control protocol parameters being selected from the group consisting of a sequence type of a pulse sequence for operating said magnetic resonance system to acquire said magnetic resonance data from the subject, an

Assignees

• Grodzki David
• Heismann Bjoern
• Siemens Ag

Inventors

• Grodzki David
• Heismann Bjoern

Classifications

• G01R33/543 Primary

  Control of the operation of the MR system, e.g. setting of acquisition parameters prior to or during MR data acquisition, dynamic shimming, use of one or more scout images for scan plane prescription (G01R33/546 takes precedence) · CPC title

• G01R33/482

  using a Cartesian trajectory · CPC title

• G01R33/4824

  using a non-Cartesian trajectory · CPC title