KR20090068416A - Apparatus for obtaining fusion image and driving method thereof - Google Patents

Abstract

An apparatus for obtaining a fusion image and a driving method thereof are provided to improve the quality of the image by minimizing the influence of a magnetic distortion, the reduction of a signal to noise ratio, and an eddy current. A magnetic resonance imaging unit(220) includes an RF transmitter(223) and a MR(Magnetic Resonance) data obtaining unit. The RF transmitter transmits an RF pulse signal to an object inside a magnet bore. The MR data obtaining unit obtains the MR data outputted from the object by the RF pulse signal. A positron emission tomography imaging data obtaining unit(230) is formed to be separated from the RF transmitter on a moving path of the object. The positron emission tomography data obtaining unit obtains PET(Positron Emission Tomography) data from the object. A data processor(290) generates an image fused with the positron emission tomography image and the magnetic resonance image by processing the positron emission tomography image data and the magnetic resonance image data.

Description

Apparatus for fusion image acquisition and its driving method {APPARATUS FOR OBTAINING FUSION IMAGE AND DRIVING METHOD THEREOF}

The present invention relates to a fusion image acquisition device and the like. More specifically, the present invention relates to a fusion system of a Positron Emission Tomography (PET) device and a Magnetic Resonance Imaging (MRI) device.

In general, Positron Emission Tomography (PET) devices are used to generate images of specific organs or tumors in the human body, or to generate biochemical phenomena for active sites where metabolism occurs. It is used to The PET device displays radioisotopes emitting positrons on various basic metabolites and administers them to the human body, and then detects gamma rays generated by interaction between the positrons and metabolites from outside of the body and generates tomography images. However, since the resolution of the PET image is low, the low resolution of the PET image may be obtained by using a computer tomography (CT) device or a magnetic resonance imaging (MRI) device. Complementary. Here, CT has low contrast for soft-tissues. Accordingly, the development of a system fused with PET using MRI having excellent discrimination ability of soft tissue, functional images and molecular images, and no exposure to radiation is underway.

1 is a cross-sectional view of a conventional PET-MRI fusion device.

Referring to FIG. 1, the conventional PET-MRI fusion device 100 is arranged in parallel such that the PET detector 130 and the MRI RF transmitting coil 120 have the same field of view (FOV). That is, the PET detector 130 is installed between the RF transmission coil 120 and the magnet bore 101. The structure of the PET-MRI fusion device 100 causes the interaction between PET and MRI. This creates a number of noises that degrade the quality of the image. Such noises include high magnetic field, high frequency and low frequency interference caused by MRI, magnetic field distortion caused by PET, reduction of signal-to-noise ratio, and eddy current. In particular, since the high magnetic field and high frequency energy of the MRI has the greatest impact on the PET, an RF shield 140 is installed between the RF transmitting coil 120 and the PET detector 130 to minimize this. In this case, the conductive cylinder for the RF shielding 140 degrades the performance of the RF transmission / reception coils 120 and 150 of the MRI, and eddy currents are generated in the gradient coil 110 to reduce the resolution of the MRI image. do. In addition, since the PET detector 130 is provided outside the RF transmitting coil 130 from the centrifugal of the magnet bore 101, the gamma rays emitted from the test object 170 are attenuated by the RF transmitting coil 120. Scattering reduces the magnitude of the detection signal.

In addition, as shown in Figure 1, the PET detector 130 and the conventional PET-MRI fusion device 100 is formed in a parallel structure of the RF transmission coil 120 of the MRI to secure the viewing angle of the MRI and PET A problem arises in that the size of the magnet bore 101 positioned at the outermost portion needs to be increased.

On the other hand, non-magnetic materials are used in PET detector 130, optical amplifier and electronic circuit of PET-MRI fusion device 100 to reduce the effect of PET on MRI image. However, it is difficult to use nonmagnetic materials in all devices, such as pre-amplifier capacitors and resistance devices installed in the magnet bore 101 of the MRI. Accordingly, the magnetic component present in the PET detector 130 affects the main field uniformity of the MRI. In addition, the RF shield 140 structure and other electronic circuits of the PET detector 130 may interact with a signal generated from the gradient coil 110 of the MRI to generate a eddy current. This eddy current reduces the signal-to-noise ratio of the MRI image, thereby causing a problem that the image quality of the PET-MRI fusion device 100 is degraded.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a fusion image acquisition device and a driving method thereof capable of improving the quality of a fusion image in which a positron emission tomography image and a magnetic resonance image are fused.

The apparatus for acquiring the fused image according to the present invention includes an RF transmitter for transmitting an RF pulse signal to an object in a magnet bore, and magnetic resonance (MR) data output from the object under test by an RF pulse signal. A magnetic resonance imaging unit including an acquired magnetic resonance data acquisition unit, formed on the movement path of the subject spaced apart from the RF transmitter, and positron emission to obtain Positron Emission Tomography (PET) data from the subject A tomography data acquisition unit and a data processing unit for generating a fusion image of the positron emission tomography image and the magnetic resonance image by integrating the magnetic resonance data and the positron emission tomography data.

It is preferable to further include an inspection object conveyance portion formed to convey the inspection object into the magnet bore.

The magnetic resonance imaging unit and the positron emission tomography data acquisition unit are preferably sequentially driven in accordance with the movement of the object carrier.

Preferably, the magnetic resonance data acquiring section is formed on the object carrying section.

The positron emission tomography data acquiring unit preferably further includes an RF blocking film formed to block the RF pulse signal.

In the method of driving the fusion image capturing apparatus, the magnetic resonance image capturing unit and the positron emission tomography data capturing unit are preferably driven at a time difference.

The apparatus for obtaining fused images according to the present invention can improve the quality of a fused image in which a positron emission tomography image and a magnetic resonance image are fused. In addition, it is possible to increase the physical space utilization of the fusion image acquisition device.

Hereinafter, a fusion image acquisition apparatus according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

2 to 5 are cross-sectional views of a fusion image obtaining apparatus according to an exemplary embodiment of the present invention.

Referring to FIG. 2, an apparatus for acquiring a fusion image according to an exemplary embodiment of the present invention includes an RF transmitter 223 and an RF transmitter for transmitting an RF pulse signal to an object 250 located inside a magnet bore 201. The magnetic resonance imaging unit 220 and the subject under test include a magnetic resonance data acquiring unit 225 for acquiring magnetic resonance (MR) data 227 output from the subject 250 by a pulse signal. A positron emission tomography data acquisition unit formed spaced apart from the RF transmitter 223 on the movement path of 250 and obtaining Positron emission tomography (PET) data 237 from the inspected object 250 ( 230 and a data processor 290 for integrating the magnetic resonance data 227 and the positron emission tomography data 237 to generate a fusion image 293 in which the positron emission tomography image and the magnetic resonance image are fused. . In addition, the test object carrying unit 260 formed to convey the test object 250 inside the magnet bore 201 is further included. The magnetic resonance data acquiring unit 225 may be formed on the object carrying unit 260. As illustrated in FIGS. 2 to 5, the test object carrier 260 may move in the order of the RF transmitter 223 and the positron emission tomography data acquisition unit 230 for each test site of the test object 250. .

The magnetic resonance imaging unit 220 includes an RF transmitter 223 and a magnetic resonance data acquisition unit 225 formed inside the magnet bore 201.

For magnetic resonance imaging, a static magnetic field is generated in the magnet bore 201 parallel to the direction of the axis of the object 250. The static magnetic field may be generated by the magnet bore 201. In addition, gradient magnetic fields in the three-dimensional direction orthogonal to each other are generated so as to overlap the static magnetic fields. The gradient magnetic field may be generated by the gradient magnetic field generation unit 210. The gradient magnetic field generated by the gradient magnetic field generating unit 210 has three magnetic fields that apply gradient to the intensity of the static magnetic field in the direction of three mutually perpendicular axes (that is, the slice axis, the phase axis, and the frequency axis).

The RF transmitter 223 applies an RF pulse signal corresponding to the Lamor frequency to the object 250 inside the magnet bore 201 in which the static and gradient magnetic fields are formed. Each nuclide constituting the subject 250 has its own Lamor frequency when placed within a constant magnetic field. Accordingly, the test object 250 to which the RF pulse signal is applied emits magnetic resonance (MR) signals corresponding to the lamore frequency. These magnetic resonance signals are collected by the magnetic resonance data acquisition unit 225 formed on the object carrier 260 and transmitted to the data processing unit 290. Here, the magnetic resonance data acquisition unit 225 is generally RF Means a receiving coil unit.

The positron emission tomography data acquisition unit 230 is spaced apart from the RF transmitter 223 on the moving path of the subject 250 and acquires Positron emission tomography (PET) data 237. Do this. The positron emission tomography data acquisition unit 230 is spaced apart from each other on different concentric circles with the RF transmitter 223 applying the RF pulse signal, and is formed inside and outside the magnet bore 201, respectively. That is, the RF transmitter 223 and the positron emission tomography data acquirer 230 are formed in a serial structure, and the RF transmitter 223 and the positron emission tomography data acquirer 230 are moved from the moving point of the object 250. ) May be arranged in order. Accordingly, the subject 250 moves by the subject carrier 260 into the magnet bore 201, and the magnetic resonance imaging unit 220 and the positron emission tomography data acquisition unit 230 sequentially. Can be driven.

An RF blocking layer 240 may be formed on the positron emission tomography data acquisition unit 230 to block an RF pulse signal and a high frequency signal emitted from the RF transmitter 223. Accordingly, it is possible to maintain the sensitivity of the image obtained from the positron emission tomography data acquisition unit 230.

Magnetic resonance imaging time is several times faster than positron emission tomography time. Accordingly, the apparatus 200 for obtaining a fusion image first moves the object 250 to the RF transmitter 223 and then acquires the magnetic resonance data 227 from the object 250. Thereafter, the apparatus 200 for obtaining fusion images acquires the positron emission tomography data 237 after moving the subject 250 to the positron emission tomography data acquisition unit 230. Therefore, the magnetic resonance imaging unit 220 and the positron emission tomography data acquisition unit 230 are driven with a time difference.

The data processor 290 generates a fused image 293 using the acquired magnetic resonance data 227 and the positron emission tomography data 237.

Therefore, in the fusion image acquisition apparatus 200, the RF transmitter 223 and the positron emission tomography data acquisition unit 230 have a serial structure and are separated from each other, so that the positron emission tomography data acquisition unit 230 is magnetic. Effects such as magnetic field distortion, signal-to-noise ratio reduction, eddy current, etc. on the resonance imaging unit 220 may be minimized. In addition, the influence of the high magnetic field and strong high-frequency energy on the positron emission tomography data acquisition unit 230 by the magnetic resonance imaging unit 220 may be minimized. Accordingly, the fusion image acquisition apparatus 200 may implement high quality fusion images by integrating magnetic resonance data and positron emission tomography data with minimized interference components.

6 is a cross-sectional view of the conventional PET-MRI fusion device having a magnet bore of the same size and the cross-section of the fusion image acquisition device according to a preferred embodiment of the present invention.

First, in the conventional PET-MRI fusion apparatus 100 shown in FIG. The case where the cross section of the b-b 'direction including the RF transmitter 223 of 200 is compared is demonstrated. Referring to FIG. 6, the sizes of the magnet bore 101 of the conventional PET-MRI fusion device 100 and the magnet bore 201 of the fusion image acquisition device 200 are the same. In this case, the second field of view (FOV) 280 inside the fusion image acquisition device 200 may be larger than the first viewing angle 180 inside the conventional PET-MRI fusion device 101. .

Next, in the conventional PET-MRI fusion apparatus 100 shown in FIG. A case in which cross sections in the c-c 'direction including the positron emission tomography data acquisition unit 230 at 200 are compared will be described. Referring to FIG. 6, the third viewing angle 283 inside the fusion image acquisition device 200 may also be larger than the first viewing angle 180 inside the conventional PET-MRI fusion device 100.

Therefore, when the size of the magnet bore is the same condition, the fusion image acquisition apparatus 200 is formed by the RF transmitter 223 and the positron emission tomography data acquisition unit 230 in a series structure, the conventional PET-MRI fusion device It is possible to secure a larger internal space than (100).

7 is a cross-sectional view of a conventional PET-MRI fusion device having a same viewing angle inside a magnet bore and a fusion image acquisition device according to a preferred embodiment of the present invention.

First, in the conventional PET-MRI fusion apparatus 100 shown in FIG. The case where the cross section of the b-b 'direction including the RF transmitter 223 of 200 is compared is demonstrated. Referring to FIG. 7, the fifth viewing angle 285 of the magnet bore 201 of the fusion imaging apparatus 200 is greater than the fourth viewing angle 183 of the magnet bore 101 of the conventional PET-MRI fusion apparatus 100. It can be formed small.

Next, the cross section in the a-a 'direction including the RF coil 120 and the PET detector 130 in the conventional PET-MRI fusion device shown in FIG. 1 and the positron emission monolayer of the fusion image acquisition device shown in FIG. The case where the cross section of c-c 'direction including the imaging data acquisition part 230 is compared is demonstrated. Referring to FIG. 7, the sixth viewing angle 285 of the magnet bore 201 of the fusion imaging device 200 is larger than the fourth viewing angle 183 of the magnet bore 101 of the conventional PET-MRI fusion device 100. It can be formed small.

Therefore, when the width of the inside of the magnet bore is the same condition, the overall size of the fusion image acquisition device 200 may be implemented to be smaller than the conventional PET-MRI fusion device 100. Accordingly, the space utilization of the fusion image acquisition device 200 may be increased.

In the fusion image acquisition apparatus according to the preferred embodiment of the present invention, since the magnetic bores are separately formed in series inside and outside of the magnet bore, effects such as magnetic field distortion, signal-to-noise ratio reduction, and eddy current may be minimized. Accordingly, the quality of the fused image in which the positron emission tomography image and the magnetic resonance image are fused can be improved. In addition, it is possible to increase the physical space utilization of the fusion image acquisition device.

Features of the method of driving the fusion image acquisition device according to an embodiment of the present invention, as shown in Figures 2 to 5 attached, the subject 250 located inside the magnet bore (201) Bore (201) The magnetic resonance data acquiring unit 225 for acquiring the magnetic resonance (MR) data 227 outputted from the test object 250 by the RF pulse signal and the RF transmitter 223 for transmitting the RF pulse signal. The magnetic resonance imaging unit 220 including the magnetic resonance imaging unit 220 is spaced apart from the RF transmitter 223 on a moving path of the test object 250, and positron emission tomography (PET) data from the test object 250 is included. Convergence image of positron emission tomography image and magnetic resonance image by integrating positron emission tomography data acquisition unit 230 and magnetic resonance data 227 and positron emission tomography data 237 to obtain (237) Data Processing to Generate (293) In the fused image capture device that includes the unit 290, the magnetic resonance imaging unit (220) and positron emission tomography data acquisition unit 230 will be driven with a time difference.

Description of the driving method of the fusion image acquisition apparatus is replaced by the description of the above-described fusion image acquisition apparatus.

As described above, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the appended claims rather than the foregoing description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

1 is a cross-sectional view showing a conventional PET-MRI fusion device.

2 to 5 are cross-sectional views showing a fusion image acquisition apparatus according to a preferred embodiment of the present invention.

6 and 7 is a view comparing the fusion image acquisition device according to a preferred embodiment of the present invention and the conventional PET-MRI fusion device.

******** Explanation of symbols for the main parts of the drawing ********

201: magnet bore

210: gradient magnetic field generation unit

220: magnetic resonance imaging unit

223: RF transmitter

225: magnetic resonance data acquisition unit

230: Positron emission tomography data acquisition unit

240: RF cutout

290: data processing unit

Claims (6)

An RF transmitter for transmitting an RF pulse signal to an object under test in a magnet bore, and a magnetic resonance data acquisition unit for obtaining magnetic resonance (MR) data output from the object under test by the RF pulse signal; Magnetic resonance imaging unit; A positron emission tomography data acquisition unit formed spaced apart from the RF transmitter on the movement path of the subject and obtaining Positron Emission Tomography (PET) data from the subject; And And a data processor configured to integrate the magnetic resonance data and the positron emission tomography data to generate a fusion image in which the positron emission tomography image and the magnetic resonance image are fused. The method of claim 1, And a test subject carrying section configured to convey the test subject into the magnet bore. The method of claim 2, The magnetic resonance imaging unit and the positron emission tomography data acquisition unit are sequentially driven in accordance with the movement of the object carrier. The method of claim 2, And the magnetic resonance data acquisition unit is formed on the object carrier. The method of claim 1, The positron emission tomography data acquisition unit further comprises an RF blocking film formed to block the RF pulse signal, fusion image acquisition device. The method of driving the fusion image acquisition device of claim 1, And the magnetic resonance image capturing unit and the positron emission tomography data obtaining unit are driven at a time difference.

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