JPH0666630U - MRI system - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an MRI system improved so that noise from peripheral devices is not mixed into an NMR signal. [Structure] An MRI system 1 including an MRI apparatus 2 including an MRI apparatus main body 2A and a detection apparatus 2B, and a large number of peripheral devices 3A, 3B, ... To the peripheral device 3A, the switch 4A, etc.
The operation of A, 3B, ... Is suppressed. [Effect] NMR without being disturbed by noise from peripheral devices
The signal can be received and the image quality can be improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an MRI system, and more particularly to an MRI system including an MRI device and a plurality of peripheral devices.

[0002]

[Prior art]

 FIG. 4 is an explanatory diagram of an example of a conventional MRI system. The MRI system 51 includes an MRI apparatus 52 including an MRI apparatus main body 52A and a detection apparatus 52B, and peripheral devices 3A, 3B, .... The MRI apparatus main body 52A controls the detection apparatus 52B connected via the cable 52K based on the user's instruction and the stored operation procedure, and executes the MR imaging pulse sequence. The detection device 52B includes a table on which the subject is placed, a magnetic field generation coil, an RF transmission coil, an NMR signal reception coil, and the like, and is installed in the shield room SR. Then, the NMR signal generated from the subject is received. The MRI apparatus main body 52A takes in the NMR signal received by the detection apparatus 52B via the cable 52K and reconstructs an image.

Peripheral devices 3A, 3B, ... Are devices for taking out biological signals (ECG, etc.) of a subject, input / output display devices (man-machine interface), devices for table transportation, and the like. The auxiliary machines 3Aa, 3Bb, ... Are arranged in the shield room SR. Cables 3AK, 3BK, ... Connecting the peripheral devices 3A, 3B, ... And the respective auxiliary machines 3Aa, 3Bb, .. are filters having the frequency-specified band FA, FB ,. There is.

[0004]

[Problems to be solved by the device]

 In the conventional MRI system 51 described above, the detection device 52B and the auxiliary device 3Aa are configured so that noise generated by the peripheral device itself or noise caused by external radio waves mediated by the peripheral device does not interfere with the reception of the weak NMR signal. , 3Bb, ... Are accommodated in the shield room SR, and filters FA, FB ,. However, as peripheral equipment became digitalized and high-speed clock signals began to be used in peripheral equipment, wideband noise caused by high-speed clock signals could not be completely cut by the filters and entered the shield room SR, The problem of mixing in the NMR signal has arisen. Therefore, an object of the present invention is to provide an MRI system improved so that noise from peripheral devices (particularly, broadband noise caused by a high-speed clock signal) is not mixed into an NMR signal.

[0005]

[Means for Solving the Problems]

 The MRI system of the present invention utilizes an NMR phenomenon to receive an NMR signal from a subject to obtain an MR image, and an MRI system including a plurality of peripheral devices. A constitutional feature is that the peripheral device operation suppressing means for suppressing the operation of a predetermined peripheral device is provided to prevent the peripheral device from becoming a noise source for an NMR signal.

[0006]

[Action]

 In the MRI system of the present invention, the peripheral device operation suppressing means suppresses the operation of a predetermined peripheral device during the reception period of the NMR signal. For example, stop the high-speed clock in the peripheral device that becomes the noise source. Therefore, during the reception period of the NMR signal, noise is not generated from the peripheral device, and noise is not mixed in the NMR signal.

[0007]

【Example】

 Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. However, this does not limit the present invention. FIG. 1 is an explanatory view of an embodiment of the MRI system of the present invention. The MRI system 1 includes an MRI apparatus 2 including an MRI apparatus body 2A and a detection apparatus 2B, peripheral devices 3A, 3B, ... And switches 4A ,.

The MRI apparatus main body 2A controls the detection apparatus 52B connected via the cable 2K based on the user's instruction and the stored operation procedure to execute the pulse sequence of MR imaging. Further, the MRI apparatus main body 2A outputs the operation suppression signal S to the peripheral device 3A, the switch 4A, and the like only during the reception period of the NMR signal. The detection device 2B includes a table on which the subject is placed, a magnetic field generation coil, an RF transmission coil, an NMR signal reception coil, and the like, and is installed in the shield room SR. Then, the NMR signal generated from the subject is received. The MRI apparatus main body 2A takes in the NMR signal received by the detection apparatus 2B via the cable 2K and reconstructs an image.

The peripheral devices 3A, 3B, ... Are devices for taking out biological signals (ECG, etc.) of the subject, input / output display devices (man-machine interface), devices for table transportation, etc. The auxiliary machines 3Aa, 3Bb, ... Are arranged in the shield room SR. Cables 3AK, 3BK, ... Connecting the peripheral devices 3A, 3B, ... And the respective auxiliary machines 3Aa, 3Bb, .. are filters having the frequency-specified band FA, FB ,. There is. The peripheral device 3A receives the operation suppression signal S from the MRI apparatus main body 2A and stops the part of the digital signal processing. The switch 4A receives the operation suppression signal S from the MRI apparatus main body 2A and stops the power supply of the peripheral device 3B. The peripheral device 3B is, for example, a switching power supply or a bias power supply for a high frequency coil.

FIG. 2 is a time chart of the operation of the MRI system 1. In the preparation / excitation period P1, the peripheral devices 3A, 3B, ... Are used to take out the biological signal of the subject or to carry the table on which the subject is placed to a predetermined position in the detection device 2B. Also, instructions such as scan conditions are received from the user. Also, based on the user's instructions and the stored operation procedure, prepare the scan such as positioning of the diagnostic region and pulse sequence creation. Further, an RF pulse is transmitted to excite the subject.

In the reception period P2, an NMR signal is received. FIG. 3 illustrates a pulse sequence of general MR imaging. In the figure, TE is the echo time. SL is a slice gradient and RP is a rephase gradient. PH is the phase encode gradient. PP is the pre-phase gradient and RO is the readout gradient. The reception period P2 is a period in which at least an NMR signal is sampled by the AD converter, but may be an output period of the readout gradient RO. Here, the NMR signal is sampled by the AD converter, and the operation suppression signal S is output in synchronization with it. Peripherals stop the digital processing part or stop altogether.

In the data processing period P3, data processing such as image reconstruction is executed based on the NMR signal. At this time, the output of the operation suppression signal S is stopped and the peripheral device is operated.

As described above, in the MRI system 1, in order to suppress the operation of the peripheral devices 3A, 3B, ... During the reception period P2, the peripheral devices 3A, 3B ,. No noise is mixed in. It is more preferable to suppress the operation of the portion of the MRI apparatus 2 that is not involved in the reception and acquisition of the NMR signal during the reception period P2, because noise from the inside of the MRI apparatus 2 can be prevented from being mixed in.

[0014]

[Effect of device]

 According to the MRI system of the present invention, since the operation of the peripheral device is suppressed during the reception period of the NMR signal, it is possible to reliably prevent noise from the peripheral device from being mixed into the NMR signal, and improve the image quality. . In addition, it is possible to reduce the number of parts for the normal noise suppression part.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of an MRI system of the present invention.

2 is a time chart of the operation of the system of FIG.

FIG. 3 is an exemplary diagram of a pulse sequence according to the system of FIG.

FIG. 4 is an explanatory diagram of an example of a conventional MRI system.

[Explanation of symbols]

 1 MRI system 2 MRI device 2A MRI device main body 2B Detection device 3A Peripheral device 4A switch SR Shield room P1 1st period P2 2nd period

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 9219-2J G01N 24/00 Z 8203-2G G01R 33/22 T

Claims (1)

[Scope of utility model registration request] 1. An NM from an object using the NMR phenomenon
An MRI system including an MRI apparatus that receives an R signal to obtain an MR image and a plurality of peripheral devices, and includes peripheral device operation suppressing means that suppresses operation of a predetermined peripheral device during an NMR signal reception period. , The peripheral equipment is NM
An MRI system characterized in that it is prevented from becoming a noise source for the R signal.