JP3501414B2 - Magnetic resonance diagnostic equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic resonance diagnostic apparatus for non-invasively diagnosing a subject, and more particularly to a technique for collecting biochemical information. 2. Description of the Related Art In recent years, magnetic resonance diagnostic apparatuses have been widely used in the development of medical diagnostic apparatuses. A magnetic resonance diagnostic apparatus applies an RF pulse and x, x, and x to a subject placed in a uniformly formed static magnetic field in a predetermined pulse sequence.
A gradient magnetic field in the y- and z-axis directions is applied, and magnetic resonance signals generated thereby are collected to reconstruct a magnetic resonance image. In such a magnetic resonance diagnostic apparatus,
Spectroscopic imaging is performed to obtain biochemical information such as energy metabolism and substance metabolism of nuclides in a living body. Conventionally, when performing spectroscopic imaging, a region where a measurement object is present in a subject is imaged by a pulse sequence for imaging, and a grid-shaped region of interest is set on this image, and the region is set in this region. Perform spectroscopic imaging. As a result, for example, spectrum data as shown in FIG. 5 is obtained, and based on this, biochemical information is analyzed. [0004] However, in such a conventional magnetic resonance diagnostic apparatus, the position of the lattice-shaped region of interest is fixed on the image, so that it cannot be measured with respect to the object to be measured. The region of interest may be set at an appropriate position. That is, a magnetic resonance image 1 as shown in FIG. 6A is obtained, and when it is desired to obtain biochemical information of the measurement object 3 such as a cancer cell present on this image, the image shown in FIG. As shown, a grid-like region of interest 2 of mxn [mm] is set, and biochemical information is obtained for each region. However,
In the case of the figure, although the measurement object 3 is large enough to fit in one region of interest 2, four regions of interest 2
It straddles. Therefore, spectroscopic imaging must be performed for the four regions of interest 2, and the spectral data as shown in FIG. 5 must be analyzed for each of these regions. For this reason, there is a drawback that the analysis of the information becomes complicated and leads to a decrease in the diagnostic ability. An object of the present invention is to solve such a conventional problem. It is an object of the present invention to provide a magnetic resonance apparatus capable of arbitrarily changing a set position of a region of interest in accordance with a position of an object to be measured. It is to provide a diagnostic device. [0007] In order to achieve the above object, the present invention applies a high-frequency magnetic field and a gradient magnetic field to a subject placed in a uniform static magnetic field in a predetermined pulse sequence. In a magnetic resonance diagnostic apparatus capable of detecting a magnetic resonance signal generated from within the subject and collecting biochemical information of the measurement object, the magnetic resonance signal is obtained by reconstructing a magnetic resonance signal collected by a multi-slice method. On a plurality of continuous magnetic resonance images, setting means for setting a voxel-shaped region of interest, and the multi-slice image of the multi-slice image according to the position of an object to be measured for biochemical information on the magnetic resonance image In the plane direction, the position of the region of interest is moved and the size is changed, and in order to change the region of interest in the depth direction, the multi-slice images are sequentially displayed, and two images are designated. It is further characterized in that it comprises a changing means for changing the position dividing the voxel-shaped region of interest, and a collecting means for collecting biochemical information of the measurement object existing in the region of interest. According to the present invention configured as described above, the position of the region of interest can be arbitrarily set according to the position of the measurement target existing on the magnetic resonance image. For a plurality of images captured by the multi-slice method, a voxel-shaped region of interest can be arbitrarily set also in the depth direction of the images. Therefore, the measurement target can be placed in one region of interest even on the three-dimensional image. Therefore, analysis of biochemical information becomes easy. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a magnetic resonance diagnostic apparatus according to the present invention. The magnetic resonance diagnostic apparatus shown in the figure includes a static magnetic field coil 15 for forming a uniform static magnetic field H, a gradient magnetic field coil 4 for forming a gradient magnetic field in each of x, y, and z directions, And an RF coil 8 for receiving a pulse and applying the generated magnetic resonance signal. Also, a static magnetic field power supply 16 for supplying power to the static magnetic field coil 15, an RF transmitter 9 for outputting a high-frequency pulse signal to the RF coil 8, and an RF receiver for taking in a magnetic resonance signal received by the RF coil 8 10 and gradient magnetic field coil 4
A gradient magnetic field control device 6 for controlling the power supplied to the power supply, and an amplifier 5 for amplifying the output. The RF transmitter 9, the RF receiver 10, and the gradient magnetic field control device 6 are controlled by the control device 7. Works below. That is, the control device 7 performs control such that a high-frequency pulse and a gradient magnetic field are applied in accordance with the pulse sequence given from the arithmetic device 12. The output of the RF receiver 9 is supplied to a storage device 11 for reconstructing and storing a magnetic resonance image, and the stored magnetic resonance image is displayed on a display device 13 under the control of an arithmetic unit 12. It has become so. Further, the arithmetic unit 12 has an ROI setting unit 12a for displaying a grid-like region of interest at a desired position on the magnetic resonance image displayed on the display unit 13, and the input unit 14 Is input to set the position of the ROI. Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG. First, the RF transmitter 9 and the gradient magnetic field control device 6 are driven by a predetermined pulse sequence (for example, a spin echo method), and a magnetic resonance signal generated at a desired portion of the subject is collected by the RF receiver 10,
This is reconstructed in the storage device 11 to create a magnetic resonance image (step ST1). Then, this image is displayed on the display device 13 (step ST2). As a result, for example, as shown in FIG. 3A, a magnetic resonance image 1 in which the measurement target 3 such as cancer exists is obtained. Thereafter, when a display command of a ROI (region of interest) is inputted from the input device 14, the region of interest 2 in the form of a mxn [mm] lattice as shown in FIG.
Is displayed. Then, the operator sees this screen and recognizes that the measurement target 3 exists over the four regions of interest 2, and issues a command to move the position of the region of interest 2 from the input device 14, and an instruction to move the position of the region of interest. A command to determine the size is input (step ST3). Further, the size of the voxel is determined as shown in FIG. 7 (step ST4). Here, FIG. 7A shows a case where the voxel size i × j is 3 × 3, and FIG. 7B shows a case where the voxel size is 7 × 7. Then, the ROI setting unit 12a changes the position and size of the region of interest (step ST5). As a result, FIG. 3 (C)
Is obtained as shown in FIG. If the position and size are acceptable (YES in step ST6), a scan plan is made by setting the spectroscopic imaging conditions, for example, the repetition time TR, the echo time TE, and the like (step S6).
T7). Next, spectroscopic imaging is performed using this scan plan (step ST8), and the collected data is displayed on the display device 13 (step ST8).
9). In this way, spectroscopic imaging can be performed by placing the measurement target 3 on the screen in one region of interest 2. As described above, in the present embodiment, the position, size, and number of voxels of the region of interest 2 can be set arbitrarily, so that the object to be measured can be placed in one region of interest 2. , Spectrum analysis becomes easy. FIG. 4 is an explanatory view showing a second embodiment of the present invention. In the above-described embodiment, an example has been described in which the region of interest 2 is arbitrarily set on one image. In this embodiment, the region of interest in the normal direction of a plurality of continuous images captured by the multi-slice method is defined. To set. That is, the region of interest is set in a voxel shape, and the position of the voxel can be set not only in the plane direction of the image but also in the depth direction. Now, for example, when a multi-slice image as shown in FIG. 4 (A) is obtained, these images are sequentially displayed on the display device 13 and the operator displays the measurement object 3 on the image. The image whose existence is confirmed is designated as the start position (see FIG. 3B). After that, while confirming the existence of the measurement object 3, the image in which the existence ends is designated as the end position (see FIG. 3D). If the image from the start to the end is set as the region of interest in the depth direction, the desired measurement target 3 is contained in one region of interest, and spectroscopic imaging can be easily performed. Thus, in the second embodiment,
Since the position and size of the region of interest can be set arbitrarily also in the depth direction of the multi-slice image, when creating a three-dimensional image from this multi-slice image, the measurement target is placed in one voxel. To collect spectral data. As described above, according to the present invention,
Since the position of the region of interest at the time of performing spectroscopic imaging can be arbitrarily set on the image plane and in the depth direction, analysis of spectrum data is facilitated, and an effect of improving diagnostic performance is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of a magnetic resonance diagnostic apparatus according to the present invention. FIG. 2 is a flowchart showing the operation of one embodiment of the present invention. FIG. 3 is an explanatory diagram showing an ROI setting according to an embodiment of the present invention. FIG. 4 is an explanatory diagram showing an ROI setting according to a second embodiment of the present invention. FIG. 5 is an explanatory diagram showing spectral data collected by spectroscopic imaging. FIG. 6 is an explanatory diagram showing a conventional ROI setting. [Description of Signs] 1 Magnetic resonance image 2 Region of interest 3 Measurement object 4 Gradient magnetic field coil 7 Control device 8 RF coil 9 RF transmitter 10 RF receiver 11 Storage device 12 Processing device 12a ROI setting unit 13 Display device 14 Input device

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-168606 (JP, A) JP-A-4-158836 (JP, A) JP-A-5-154131 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A61B 5/055

Claims (1)

(57) [Claims 1] A high frequency magnetic field and a gradient magnetic field are applied in a predetermined pulse sequence to a subject placed in a uniform static magnetic field, and a magnetic field generated from inside the subject. In a magnetic resonance diagnostic apparatus capable of detecting a resonance signal and collecting biochemical information of an object to be measured, on a plurality of continuous magnetic resonance images obtained by reconstructing a magnetic resonance signal collected by a multi-slice method Setting means for setting a voxel-shaped region of interest, and the position of the region of interest in the plane direction of the multi-slice image according to the position of an object to measure biochemical information on the magnetic resonance image The multi-slice images are sequentially displayed for changing the region of interest in the depth direction while moving and changing the size of the region, and by specifying two images, the position separating the voxel-shaped region of interest Magnetic resonance imaging apparatus characterized by comprising changing means for changing, a collecting means for collecting the biochemical information of the measurement object present in the ROI.