Verifying Specifications for Magnetic Resonance Examinations

Abstract

A method for verifying at least one default value for a magnetic resonance examination, a verifying unit, a magnetic resonance device and a computer program product are provided. According to the method, at least one default value for an electromagnetic property and a sequence segment are sent to a verifying unit. The verifying unit uses the sequence segment to determine at least one electromagnetic property. The at least one default value is verified by the verifying unit with respect to the at least one electromagnetic property.

Claims

1. A method for verifying at least one default value for a magnetic resonance examination, wherein the method comprises: transmitting at least one default value for an electromagnetic property to a verifying unit, the verifying unit comprising a computing device; transmitting a sequence segment to the verifying unit; determining, by the verifying unit, at least one electromagnetic property using the sequence segment; and verifying, by the verifying unit, the at least one default value with respect to the at least one electromagnetic property.

2. The method of claim 1, wherein the at least one electromagnetic property is influenced by at least one gradient signal, a radio-frequency signal, or the at least one gradient signal and the radio-frequency signal.

3. The method of claim 1, wherein the at least one default value is specified by a standard.

4. The method of claim 1, wherein the at least one default value contains a B.sub.1+ value.

5. The method of claim 1, wherein the at least one default value contains a rate of change of a B value.

6. The method of claim 1, wherein the at least one electromagnetic property contains a magnetic field strength.

7. The method of claim 6, wherein a maximum of the magnetic field strength is determined by measurement, simulation, or measurement and simulation calculation.

8. The method of claim 6, wherein the magnetic field strength of at least one gradient axis is determined.

9. The method of claim 8, wherein magnetic field strengths of a plurality of gradient axes are superimposed.

10. The method of claim 6, wherein the magnetic field strengths is determined as a function of time.

11. The method of claim 1, wherein the verification of the sequence segment is adapted as a function of a result.

12. A verifying unit for verifying at least one default value for a magnetic resonance examination, at least one default value for an electromagnetic property and a sequence segment being transmittable to the verifying unit, the verifying unit comprising; a computing device configured to: determine at least one electromagnetic property using the sequence segment; and verify the at least one default value with respect to the at least one electromagnetic property.

13. The verifying unit of claim 12, wherein the at least one electromagnetic property is influenced by at least one gradient signal, a radio-frequency signal, or the at least one gradient signal and the radio-frequency signal.

14. The verifying unit of claim 12, wherein the at least one default value is specified by a standard.

15. The verifying unit of claim 12, wherein the at least one default value contains a B.sub.1+ value.

16. The verifying unit of claim 12, wherein the at least one default value contains a rate of change of a B value.

17. A magnetic resonance device comprising: a verifying unit for verifying at least one default value for a magnetic resonance examination, at least one default value for an electromagnetic property and a sequence segment being transmittable to the verifying unit, the verifying unit comprising; a computing device configured to: determine at least one electromagnetic property using the sequence segment; and verify the at least one default value with respect to the at least one electromagnetic property.

18. In a non-transitory computer-readable storage medium storing instructions executable by a computing device of a verifying unit to verify at least one default value for a magnetic resonance examination, the instructions comprising: transmitting at least one default value for an electromagnetic property to a verifying unit; transmitting a sequence segment to the verifying unit; determining, by the verifying unit, at least one electromagnetic property using the sequence segment; and verifying, by the verifying unit, the at least one default value with respect to the at least one electromagnetic property.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 is a schematic representation of one embodiment of a magnetic resonance device with a verifying unit; and

[0039] FIG. 2 is a block diagram of one embodiment of a method; and

[0040] FIG. 3 is a detailed block diagram of a part of a method according to an embodiment.

DETAILED DESCRIPTION

[0041] FIG. 1 is a schematic representation of one embodiment of a magnetic resonance device 10. The magnetic resonance device 10 includes a magnet unit 11 having a superconducting basic magnet 12 to generate a strong and, for example, temporally constant basic magnet field 13. The magnetic resonance device 10 also includes a patient-receiving region 14 for receiving a patient 15. In this case, the patient 15 has an implant 27. In the present exemplary embodiment, the patient-receiving region 14 has a cylindrical shape and is surrounded in a circumferential direction by the magnet unit 11. However, in principle, an embodiment of the patient-receiving region 14 deviating therefrom may be provided at any time. The patient 15 may be pushed into the patient-receiving region 14 by a patient support device 16 of the magnetic resonance device 10. To this end, the patient support device 16 includes a patient table 17 embodied movably within the patient-receiving region 14.

[0042] The magnet unit 11 further includes a gradient coil unit 18 for the generation of magnetic field gradients that are used for spatial encoding during imaging. The gradient coil unit 18 is controlled by a gradient control unit 19 of the magnetic resonance device 10. The gradient coil unit 19 includes three gradient coils (not shown in detail in FIG. 1) that are each embodied to generate a gradient field parallel to a gradient axis with the aid of a gradient signal. The magnet unit 11 further includes a radio-frequency antenna unit 20 that, in the exemplary embodiment, is configured as a body coil that is permanently integrated in the magnetic resonance device 10. The radio-frequency antenna unit 20 is configured for the excitation of atomic nuclei established in the basic magnetic field 13 by the basic magnet 12 with the aid of radio-frequency signals. The radio-frequency antenna unit 20 is controlled by a radio-frequency control unit 21 of the magnetic resonance device 10 and irradiates radio-frequency magnetic-resonance frequencies into an examination chamber substantially formed by a patient-receiving region 14 of the magnetic resonance device 10. The radio-frequency antenna unit 20 is also embodied to receive magnetic resonance signals.

[0043] To control the basic magnet 12 and to control the radio-frequency control unit 21, the gradient control unit 19 and the magnetic resonance device 10 respectively include a system control unit 22. The system control unit 22 controls the magnetic resonance device 10 centrally (e.g., for the performance of a predetermined imaging pulse sequence). The system control unit 22 includes an evaluation unit (not shown in further detail) for the evaluation of medical image data acquired during the magnetic resonance examination. The magnetic resonance device 10 also includes a user interface 23 connected to the system control unit 22. Control information such as, for example, imaging parameters, and reconstructed magnetic resonance images may be displayed on a display unit 24 (e.g., on at least one monitor, the user interface 23 for a medical operator). The user interface 23 also includes an input unit 25 by which the medical operator may input information and/or parameters during a scanning process.

[0044] The magnetic resonance device 10 also includes a verifying unit 26 with a computing unit (e.g., a computing device) including, for example, one or more processors and/or a memory (e.g., a non-transitory computer-readable storage medium) for carrying out a method for verifying at least one default value for a magnetic resonance examination. A program with program instructions for carrying out a method for verifying at least one default value for a magnetic resonance examination when the program is executed in the computing unit may be loaded into the memory of the programmable computing unit.

[0045] FIG. 2 is a block diagram illustrating one possible method for verifying at least one default value for a magnetic resonance examination. In act 110, at least one default value for an electromagnetic property and in act 120 a sequence segment are transmitted to the verifying unit 26. To carry out the acts 110 and/or 120, the system control unit 22 may, for example, include a database in which the at least one default value and/or the sequence segment is stored.

[0046] The at least one default value may be specified by a standard (e.g., for patients 15 with an implant 27). The at least one default value may also contain a B.sub.1.sup.+ value (e.g., an effective and/or maximum B.sub.1.sup.+ value), and/or a rate of change of a B value (e.g., an effective and/or maximum rate of change of a B value).

[0047] In act 130, at least one electromagnetic property is determined using the sequence segment with the aid of the verifying unit 26.

[0048] The at least one electromagnetic property may be influenced by at least one gradient signal and/or a radio-frequency signal. The electromagnetic property may, for example, contain a magnetic field strength. For example, a maximum of the magnetic field strength may be determined by measuring and/or simulation calculation.

[0049] In act 140, the at least one default value is verified with respect to the at least one electromagnetic property with the aid of the verifying unit 26.

[0050] In an optional further act, which is not shown in further detail here, the verification of the sequence segment is optionally adapted as a function of a result.

[0051] FIG. 3 shows by way of example the determination of a rate of change of a B value, which may be performed within the context of step 130. In act 131, a magnetic field strength is determined for each gradient axis of the gradient coil unit 18. This is advantageously performed for each spatial point of the patient-receiving region 14 (e.g., for the part of the patient-receiving region in which the patient 15 is located). In act 132, the magnetic field strengths determined in act 131 are vectorially superimposed. The determination of the magnetic field strengths in act 131 and corresponding superimposition in act 131 is performed as a function of time, so that the temporal derivation of the magnetic field strength dB/dt may be calculated in act 133. The amount of a peak |dB/dt|.sub.peak and/or effective value |dB/dt|.sub.rms is calculated in act 134.

[0052] The method described in detail above and the verifying unit and magnetic resonance device shown are only exemplary embodiments that may be modified by the person skilled in the art in wide variety of ways without leaving the scope of the invention. The use of the indefinite article “a” or “an” does not exclude the possibility of the features in question being present a number of times. The term “unit” does not exclude the possibility of the unit including a plurality of interacting components that may also be spatially distributed.

[0053] The elements and features recited in the appended claims may be combined in different ways to produce new claims that likewise fall within the scope of the present invention. Thus, whereas the dependent claims appended below depend from only a single independent or dependent claim, it is to be understood that these dependent claims may, alternatively, be made to depend in the alternative from any preceding or following claim, whether independent or dependent. Such new combinations are to be understood as forming a part of the present specification.

[0054] While the present invention has been described above by reference to various embodiments, it should be understood that many changes and modifications can be made to the described embodiments. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting, and that it be understood that all equivalents and/or combinations of embodiments are intended to be included in this description.