HYBRID SYSTEM FOR PERFORMING A MAGNETIC RESONANCE TOMOGRAPHY AND A RADIOFREQUENCY ABLATION, AND METHOD FOR THE OPERATION THEREOF

Abstract

The invention relates to a hybrid system for performing a magnetic resonance tomography (MRT) and a radiofrequency ablation on a patient, comprising the following characteristics: a) the hybrid system comprises a magnetic resonance tomography system in which MRT high-frequency signals for carrying out the magnetic resonance tomography can be generated and supplied on an output terminal of the magnetic resonance tomography system; b) the hybrid system comprises at least one ablation electrode for performing the radiofrequency ablation; and c) the at least one ablation electrode is coupled to the output terminal of the magnetic resonance tomography system such that the radiofrequency ablation can be carried out by the at least one ablation electrode by means of the MRT high-frequency signals. The invention also relates to a method for operating such a hybrid system.

Claims

1. A hybrid system for carrying out magnetic resonance imaging (MRI) and radiofrequency ablation on a patient (6), comprising: a magnetic resonance imaging system in which MRI radiofrequency signals for carrying out magnetic resonance imaging are generatable and providable at an output connector of the magnetic resonance imaging system, at least one ablation electrode for carrying out radiofrequency ablation, wherein the at least one ablation electrode is coupled to the output connector of the magnetic resonance imaging system such that radiofrequency ablation is able to be carried out by way of the at least one ablation electrode using the MRI radiofrequency signals.

2. The hybrid system as claimed in claim 1, further comprising a pulse generation circuit for supplying the MRI radiofrequency signals to the at least one ablation electrode in pulsed fashion.

3. The hybrid system as claimed in claim 1 wherein the at least one ablation electrode is fed with a radiofrequency signal from the MRI radiofrequency signals that is at the Larmor frequency.

4. The hybrid system as claimed in claim 1 further comprising an imaging unit associated with magnetic resonance imaging system, wherein the imaging unit is configured to record and visualize an ablation current which is fed into a patient by the at least one ablation electrode.

5. The hybrid system as claimed in claim 1 wherein hybrid system is configured to supply the MRI radiofrequency signals either to the at least one ablation electrode or to an MRI transmit coil of the magnetic resonance imaging system.

6. A method for operating a hybrid system as claimed in claim 1 comprising supplying the MRI radiofrequency signals of the magnetic resonance imaging system to the at least one ablation electrode intermittently.

7. The method as claimed in claim 6, wherein the MRI radiofrequency signals of the magnetic resonance imaging system are alternately supplied to the at least one ablation electrode and an MRI transmit coil of the magnetic resonance imaging system.

8. The method as claimed in claim 6, further comprising interrupting generation an image for visualizing the magnetic resonance imaging examination while the at least one ablation electrode is fed with the MRI radiofrequency signals.

9. The method as claimed in claim 6 further comprising recording a magnetic eddy current field generated in a patient by an ablation current of the at least one ablation electrode by the magnetic resonance imaging system; and visualizing a recorded magnetic eddy current field as a current profile.

Description

[0021] In the drawings:

[0022] FIG. 1 shows a schematic illustration of a hybrid system and

[0023] FIG. 2 shows the generation of pulsed radiofrequency signals and

[0024] FIGS. 3 and 4 show further embodiments of a hybrid system.

[0025] FIG. 1 shows a hybrid system 1 comprising a magnetic resonance imaging system 2. The magnetic resonance imaging system 2 can be of a conventional, known design. By way of example, the magnetic resonance imaging system 2 comprises a tube 5 to be used for magnetic resonance imaging examinations, into which a patient 6 can be placed. The MRI radiofrequency signals provided by a radiofrequency amplifier 7 of the magnetic resonance imaging system 2 are transferred to the patient 6 by way of transmit coils, which are arranged, for example, in the wall of the tube 5. The resultant signals of the magnetic resonance imaging system, recorded on the receiver side, are captured and processed by way of an imaging unit 3 of the magnetic resonance imaging system 2. The image information generated thereby can be presented on an image display device 4.

[0026] The hybrid system 1 is further configured to carry out a radiofrequency ablation on the patient 6. To this end, at least one ablation electrode 9 is present, which can be placed, for example, against a tumor to be removed within the patient 6. The ablation electrode 9 is connected to an output connector 8 of the magnetic resonance imaging system, e.g., an output connector of the RF output amplifier 7, via a line. In this way, the MRI radiofrequency signals provided at the output connector 8 are supplied to the ablation electrode 9 and fed into the patient 6.

[0027] FIG. 2 shows an exemplary time profile of the MRI radiofrequency signals 20. The MRI radiofrequency signals 20 can be generated in the form of individual pulse trains, of which two pulse trains are illustrated in FIG. 2. A pulse train consists of a multiplicity of individual radiofrequency pulses. There is a pause, e.g., a pause of approximately 2 seconds in the illustrated example, between the individual pulse trains. The line 21 represents a mean voltage, which is established as effective voltage for the ablation process on the ablation electrode 9. By way of example, the first pulse train 20 illustrated in FIG. 2 can be used for radiofrequency ablation and consequently only be supplied to the ablation electrode and the other, second illustrated pulse train 20 can be used for imaging within the scope of magnetic resonance imaging, i.e., this pulse train is only supplied to an MRI transmit coil.

[0028] FIG. 3 shows further features of the hybrid system 1, which can be realized, for example, in the hybrid system explained on the basis of FIG. 1. A patient couch 30, on which the patient 6 is placed, is identifiable. Further, the ablation electrode 9 is illustrated once again. The ablation electrode 9 is connected to a function block 35 by way of an interface circuit 38. The function block 35 contains a changeover switch 37, e.g., in the form of an RX-TX switch. By way of the changeover switch 37, the ablation electrode 9 can alternatively be connected to a transmitter channel or receiver channel of the hybrid system 1. The transmitter channel can be connected to the function block 35 via a transmitter line 33, the receiver channel via a receiver line 34. The function block 35 comprises a preamplifier 36 for the receiver channel, said preamplifier being connected to the receiver line 34. The transmitter line 33 and the receiver line 34 are connected to a coil plug 32, to which the transmitter channel and the receiver channel of the hybrid system 1 can be connected. The coil plug 32 can be connected to a coil terminal 31, from which the radiofrequency signals for imaging or ablation can be taken.

[0029] During the operation of the hybrid system as per FIG. 3, the changeover switch 37 is changed over in computer-controlled fashion, for example alternately in the case of the pulse trains illustrated in FIG. 2, such that the MRI radiofrequency signals are alternately supplied to the one or the other application, and so the ablation electrode 9 alternately acts in the transmission case or in the reception case.

[0030] FIG. 4 shows a further configuration of the hybrid system 1, which differs from the embodiment of FIG. 3 as follows: An MRI coil 40, e.g., in the form of a conductor loop, is present for MR imaging or for recording the magnetic fields to carry out MR imaging. The MRI coil 40 is connected to the function block 35 by way of an interface circuit 42. In addition to the aforementioned changeover switch 37 and the preamplifier 36, the function block 35 additionally comprises a further changeover switch 41.

[0031] During the operation of the hybrid system as per FIG. 4, the changeover switch 41 is changed over in computer-controlled fashion, for example alternately in the case of the pulse trains illustrated in FIG. 2, such that the MRI radiofrequency signals are alternately supplied to the ablation electrode 9 or the MRI coil 40.

[0032] The ablation application is possible when the changeover switch 41 is switched to the ablation electrode 9 and the MR imaging application is possible when said changeover switch is switched to the MRI coil 40.