Method and apparatus to determine a complete parameter of a magnetic resonance pulse sequence

Patent metadata

Field	Value
Publication number	US-9835703-B2
Application number	US-201313848985-A
Country	US
Kind code	B2
Filing date	Mar 22, 2013
Priority date	Mar 22, 2012
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

In a method to determine a complete parameter of a pulse sequence composed of multiple pulse sequence modules for operating a magnetic resonance examination apparatus parameter information of the pulse sequence modules is stored in a memory in leaves and nodes of a tree structure, and the parameter information stored in the tree structure is evaluated to determine the complete parameter of the pulse sequence.

First claim

I claim as my invention:

1. A method to determine a complete parameter of a pulse sequence comprised of multiple sequence modules, for operating a magnetic resonance apparatus, comprising:
electronically storing multiple pulse sequences, each as a tree structure comprising a plurality of nodes, in which parameter information of the respective pulse sequence modules of the respective pulse sequence is individually stored, with each node being connected in the tree structure by respective edges to multiple leaves, with a detail of the parameter information of the respective node being stored in each leaf connected thereto;
making an entry into a processor that selects a pulse sequence from said memory, as selected pulse sequence for operating the magnetic resonance apparatus and, from the processor, accessing and retrieving the tree structure for the selected pulse sequence;
in said processor, executing a tree structure evaluation algorithm for the retrieved tree structure for the selected pulse sequence, in order to determine a complete parameter of the selected pulse sequence as a combination of the parameter information stored in the nodes and leaves of that tree structure; and
in the processor, generating an electrical signal representing the complete parameter of the selected pulse sequence, and making the electronic signal available from the processor as an output.

2. A method as claimed in claim 1 comprising storing a repetition count of leaves in at least one node of said tree structure.

3. A method as claimed in claim 1 comprising associating a repetition count of leaves with at least one edge of said tree structure.

4. A method as claimed in claim 1 comprising evaluating the parameter information stored in respective portions of said tree structure, each portion comprising at least one node, in order to determine a partial parameter of said pulse sequence from each portion, and combining all partial parameters from all portions of said tree structure to determine said complete parameter.

5. A method as claimed in claim 1 comprising evaluating parameter information details from leaves of said tree structure, and compiling and storing the parameter information details from said leaves as the parameter information of the respective node connected to those leaves in said tree structure.

6. A method as claimed in claim 1 comprising, in said tree structure evaluation algorithm, implementing a depth search or a width search to traverse said tree structure and evaluate said parameter information stored in said tree structure.

7. A method as claimed in claim 1 comprising evaluating said tree structure to generate a parameter sequence with parameter information for each of said pulse sequence modules.

8. A method as claimed in claim 7 comprising comparing respective parameter information of successive pulse sequence modules.

9. A method as claimed in claim 8 comprising merging parameter information of said successive pulse sequence modules if the parameter information of two successive pulse sequence modules is the same.

10. A method as claimed in claim 7 comprising generating, as said parameter information, power information, or information describing a specific absorption rate of a pulse sequence module, and comprising calculating a specific absorption rate for the pulse sequence from said parameter information.

11. A method as claimed in claim 1 wherein said parameter information describes a duration of a pulse sequence module, and comprising calculating a total duration of said pulse sequence from said parameter information.

12. A method as claimed in claim 1 wherein said parameter information is information describing an energy of a pulse sequence module, and comprising calculating a total energy of said pulse sequence from said parameter information.

13. A magnetic resonance apparatus comprising:
a magnetic resonance data acquisition unit configured to operate according to a pulse sequence comprised of multiple sequence modules;
a memory in which multiple pulse sequences are stored, each as a tree structure comprising a plurality of nodes, in which parameter information of the respective pulse sequence modules of the respective pulse sequence is individually stored, with each node being connected in the tree structure by respective edges to multiple leaves, with a detail of the parameter information of the respective node being stored in each leaf connected thereto;
a processor having an input interface configured to receive an entry into the processor that selects a pulse sequence from said memory, as a selected pulse sequence for operating the magnetic resonance apparatus, and said the processor being configured to then access and retrieve the tree structure for the selected pulse sequence;
said processor being configured to execute a tree structure evaluation algorithm for the retrieved tree structure for the selected pulse sequence, in order to determine a complete parameter of the selected pulse sequence as a combination of the parameter information stored in the nodes and leaves of that tree structure; and
said processor being configured to generate an electrical signal representing the complete parameter of the selected pulse sequence, and to make the electronic signal available from the processor as an output.

14. A non-transitory, computer-readable data storage medium encoded with programming instructions, said storage medium being loaded into a processor of a magnetic resonance apparatus, that comprises a magnetic resonance data acquisition scanner operable according to a pulse sequence that comprises a plurality of sequence modules, and a memory in which multiple pulse sequences are stored, each as a tree structure comprising a plurality of nodes, in which parameter information of the respective pulse sequence modules of the respective pulse sequence is individually stored, with each node being connected in the tree structure by respective edges to multiple leaves, with a detail of the parameter information of the respective node being stored in each leaf connected thereto, said programming instructions causing said processor to:
receive an entry into a processor that selects a pulse sequence from said memory as a selected pulse sequence for operating the magnetic resonance apparatus and to then access and retrieve the tree structure for the selected pulse sequence;
execute a tree structure evaluation algorithm for the retrieved tree structure for the selected pulse sequence, in order to determine a complete parameter of the selected pulse sequence as a combination of the parameter information stored in the nodes and leaves of that tree structure; and
generate an electrical signal representing the complete parameter of the selected pulse sequence, and make the electronic signal available from the processor as an output.

Assignees

• Kuehn Bernd
• Siemens Ag

Inventors

• Kuehn Bernd

Classifications

• G01R33/44 Primary

  using nuclear magnetic resonance [NMR] (G01R33/24, G01R33/62 take precedence) · CPC title

• G01R33/546

  Interface between the MR system and the user, e.g. for controlling the operation of the MR system or for the design of pulse sequences · CPC title

• G01R33/288

  Provisions within MR facilities for enhancing safety during MR, e.g. reduction of the specific absorption rate [SAR], detection of ferromagnetic objects in the scanner room · CPC title

• 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

• A61B5/055 Primary

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title